Re: Leaning tower of falcon 9

[Robert Clark]

The LA Times is reporting today's landing attempt was unsuccessful:

SpaceX launches two satellites, but drone ship landing is unsuccessful.
http://www.latimes.com/business/la-fi-spacex-launch-20160614-snap-story.html

Elon Musk Verified account
‏@elonmusk
Looks like thrust was low on 1 of 3 landing engines. High g landings v
sensitive to all engines operating at max.
https://twitter.com/elonmusk/status/743097337782763521

My opinion, in order to land successfully in a consistent fashion SpaceX
will have to give the F9 hovering ability.

High g landings are endemic to a "hover-slam" landing, more commonly
referred to as a "suicide-burn", more accurately referred to as "land or
slam", since without hovering ability, you only get one chance at it. You
either stick the landing on the first try, or you crash and burn.

Bob Clark


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"Dr J R Stockton" wrote in message
news:PiD6NT66...@invalid.uk.co.demon.merlyn.invalid...

In sci.space.policy message <MPG.31bf250f...@news.eternal-
september.org>, Mon, 6 Jun 2016 07:14:24, Jeff Findley
<jfin...@cinci.nospam.rr.com> posted:

>In article <vONymAZN...@invalid.uk.co.demon.merlyn.invalid>,
>repl...@merlyn.demon.co.uk.invalid says...
>>
>> In sci.space.policy message <MPG.31bba923b...@news.eternal-
>> september.org>, Fri, 3 Jun 2016 15:48:38, Jeff Findley
>> <jfin...@cinci.nospam.rr.com> posted:
>>
>> >3. Getting the thing vertical when the barge is moving in the ocean
>> >would be "challenging".
>>
>> I think not. One need only pump ballast within the barge in the
>> compensating direction. It is getting the thing perpendicular to the
>> deck that should be difficult.
>
>You could do this, but I would think doing so would screw up the ability
>for the tug to get it back to port in a timely fashion.

Many seagoing vessels have been towed to port, often in extreme
conditions, with very considerable lists. Even the "Flying Enterprise"
was nearly saved : <https://en.wikipedia.org/wiki/SS_Flying_Enterprise>.


>> Since the vast majority of the mass of an empty stage is at the bottom,
>> actual tilt is relatively unimportant.
>
>In other words, "if it ain't broke, don't fix it". So what if it was
>leaning? It made it back to port safely, which is what matters.

Yes; I was only challenging the 'would be "challenging"', not advocating
that it would be _useful_ to do it.


--
(c) John Stockton, Surrey, UK. ¬@merlyn.demon.co.uk Turnpike v6.05
MIME.
Merlyn Web Site < > - FAQish topics, acronyms, &
links.



---
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[Jeff Findley]

In article <njrt9k$hej$1...@dont-email.me>,
rgrego...@gmSPAMBLOACKail.com says...

>
> The LA Times is reporting today's landing attempt was unsuccessful:
>
> SpaceX launches two satellites, but drone ship landing is unsuccessful.
> http://www.latimes.com/business/la-fi-spacex-launch-20160614-snap-story.html

Yes, but the launch *was* successful, so the paying customer is happy
and the Falcon flight program will continue. :-)

> Elon Musk Verified account
> ?@elonmusk

> Looks like thrust was low on 1 of 3 landing engines. High g landings v
> sensitive to all engines operating at max.
> https://twitter.com/elonmusk/status/743097337782763521

He also Tweeted that SpaceX has already been working on ways to handle
this situation. In other words, it's just like the launch that "ran out
of hydraulic fluid" for the grid fins. Even before that failure, they
were working on increasing the fluid available for landings.

> My opinion, in order to land successfully in a consistent fashion
> SpaceX will have to give the F9 hovering ability.

I respectfully disagree. Again, this is a known issue that was already
being worked on. This is a *test flight program*. SpaceX has yet to
even refly a stage! Problems are expected during a test flight program.
You develop fixes for problems as they become known. In this case, the
problem was already known and a fix was already in the works. This was
not an "unknown unknown" this time. It was a known risk that they took
in order to fly the mission for the customer without making them wait
for a landing fix they largely don't care about.

The customer just wants their satellites in the proper orbit. That
mission was accomplished.

> High g landings are endemic to a "hover-slam" landing, more commonly
> referred to as a "suicide-burn", more accurately referred to as "land or
> slam", since without hovering ability, you only get one chance at it. You
> either stick the landing on the first try, or you crash and burn.

You only got one chance at final approach and landing a shuttle orbiter,
but they were all successful (with arguably a few close calls). So
that, in and of itself, doesn't disqualify the hover slam approach.
Besides, the Falcon 9 first stage is unmanned, so nobody was killed.

Remember, "perfect is the enemy of good enough". If they can make this
"good enough", they can learn from it and incorporate all of the lessons
learned in their next generation vehicle. Not everything has to be
fixed in version 1.X of a vehicle. Version 1 just has to be "good
enough". Version 2.0 can contain major upgrades and will hopefully be
even better.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.

[JF Mezei]

On 2016-06-15 18:02, Jeff Findley wrote:

> Remember, "perfect is the enemy of good enough". If they can make this
> "good enough", they can learn from it and incorporate all of the lessons
> learned in their next generation vehicle. Not everything has to be
> fixed in version 1.X of a vehicle. Version 1 just has to be "good
> enough". Version 2.0 can contain major upgrades and will hopefully be
> even better.

There is one issue not being mentioned: right now, they are testing the
limits of the vehicle.

They may come to the conclusion that for high performance launches,
there is too much speed and not enough fuel to make a reliable landing.
Say they manage 50% of landings (for sake of discussion).

What is the cost of the attempted landing (drone ship, crews, helicopter
to video it etc) as well as the cost of repairing the drone ship after
the big explosion. Economics may dictate that for such flights, it is
best to ditch in ocean. Aka: value of 5 recovered rockets < then cost of
trying to land 10 rockets, and repairing damage from the 5 failed ones.

But we're not there yet because it is too soon to establish the
economics of landing the rocket.

[Jeff Findley]

In article <5761dc6e$0$29122$c3e8da3$3863...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-15 18:02, Jeff Findley wrote:
>
> > Remember, "perfect is the enemy of good enough". If they can make this
> > "good enough", they can learn from it and incorporate all of the lessons
> > learned in their next generation vehicle. Not everything has to be
> > fixed in version 1.X of a vehicle. Version 1 just has to be "good
> > enough". Version 2.0 can contain major upgrades and will hopefully be
> > even better.
>
>
> There is one issue not being mentioned: right now, they are testing the
> limits of the vehicle.
>
> They may come to the conclusion that for high performance launches,
> there is too much speed and not enough fuel to make a reliable landing.
> Say they manage 50% of landings (for sake of discussion).

Possibly, but I doubt it. Out of the last three GTO missions (high
performance) they successfully landed two out of three. That's not bad,
IMHO, considering how early in the test program it is and the fact that
Musk has said repeatedly that these post GTO mission landings are very
high risk because they really are at the very edge of the capabilities
of the stage.

> What is the cost of the attempted landing (drone ship, crews, helicopter
> to video it etc) as well as the cost of repairing the drone ship after
> the big explosion. Economics may dictate that for such flights, it is
> best to ditch in ocean. Aka: value of 5 recovered rockets < then cost of
> trying to land 10 rockets, and repairing damage from the 5 failed ones.

Ditching in the ocean was tried before the barges were available. Every
one was lost, even the ones that successfully "soft landed" on the ocean
surface. They all broke apart due to wave action. There is a reason
ships have very thick hulls. Liquid fueled launch vehicle stages do not
have thick hulls. The solid fueled shuttle SRBs survived because they
had very thick steel casings.

> But we're not there yet because it is too soon to establish the
> economics of landing the rocket.

The economics of recovering and ref-lying a vehicle is a narrow view.
Widen your view to the overall company's economics...

At this point, reducing pressure on the manufacturing capacity is quite
important, even if these first few re-flights don't "save" any money.
Also, getting the stages back for inspections is a good thing. It
allows for more engineering data than dropping it in the ocean and
letting it sink, which is the alternative that every other current US
launch vehicle provider uses.

[Greg (Strider) Moore]

"Jeff Findley" wrote in message
news:MPG.31cbb1c2a...@news.eternal-september.org...

>
>In article <5761dc6e$0$29122$c3e8da3$3863...@news.astraweb.com>,
>jfmezei...@vaxination.ca says...
>>
>> On 2016-06-15 18:02, Jeff Findley wrote:
>>
>> > Remember, "perfect is the enemy of good enough". If they can make this
>> > "good enough", they can learn from it and incorporate all of the
>> > lessons
>> > learned in their next generation vehicle. Not everything has to be
>> > fixed in version 1.X of a vehicle. Version 1 just has to be "good
>> > enough". Version 2.0 can contain major upgrades and will hopefully be
>> > even better.
>>
>>
>> There is one issue not being mentioned: right now, they are testing the
>> limits of the vehicle.
>>
>> They may come to the conclusion that for high performance launches,
>> there is too much speed and not enough fuel to make a reliable landing.
>> Say they manage 50% of landings (for sake of discussion).
>
>Possibly, but I doubt it. Out of the last three GTO missions (high
>performance) they successfully landed two out of three. That's not bad,
>IMHO, considering how early in the test program it is and the fact that
>Musk has said repeatedly that these post GTO mission landings are very
>high risk because they really are at the very edge of the capabilities
>of the stage.
>

True, but I think JF's overall point is close to the mark and mirrors what
you're saying. Ultimately, they don't need to land 100% of them
successfully, just "enough" of them. At some point they may say "this is
good enough".

>> What is the cost of the attempted landing (drone ship, crews, helicopter
>> to video it etc) as well as the cost of repairing the drone ship after
>> the big explosion. Economics may dictate that for such flights, it is
>> best to ditch in ocean. Aka: value of 5 recovered rockets < then cost of
>> trying to land 10 rockets, and repairing damage from the 5 failed ones.
>
>Ditching in the ocean was tried before the barges were available. Every
>one was lost, even the ones that successfully "soft landed" on the ocean
>surface. They all broke apart due to wave action. There is a reason
>ships have very thick hulls. Liquid fueled launch vehicle stages do not
>have thick hulls. The solid fueled shuttle SRBs survived because they
>had very thick steel casings.
>

Agreed. If they hit the ocean, write them off. But again, that should be a
pretty low number.

>> But we're not there yet because it is too soon to establish the
>> economics of landing the rocket.
>
>The economics of recovering and ref-lying a vehicle is a narrow view.
>Widen your view to the overall company's economics...
>
>At this point, reducing pressure on the manufacturing capacity is quite
>important, even if these first few re-flights don't "save" any money.
>Also, getting the stages back for inspections is a good thing. It
>allows for more engineering data than dropping it in the ocean and
>letting it sink, which is the alternative that every other current US
>launch vehicle provider uses.
>

This is one of the more overlooked values of the shuttle program: the value
of the engineering data.
Never before had we reflown engines like that. Never before had we learned
about stresses on airframes.
Never before had we learned (and unfortunately ignored) about burn-through
on large SRBs.


So yeah, this was a loss for SpaceX, but their approach takes this into
account. They're using every flight as an opportunity to learn.

>Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

[JF Mezei]

On 2016-06-15 19:41, Jeff Findley wrote:

> Possibly, but I doubt it. Out of the last three GTO missions (high
> performance) they successfully landed two out of three. That's not bad,

I agree. But it may turn out that after 10 such missions, only 2 will
have succeeded. Or maybe 9. So too early to tell.

The good news is that with every experience, they find another software
"glitch" that they can fix to give the rocket wider range of conditions
where it can land succesfully.

> high risk because they really are at the very edge of the capabilities
> of the stage.

Exactly. But financial realities will dictate whether the failure rate
for those "at the very limit" warrants even bothering to send a ship out
to greet rocket. Let it ditch in water and build a new one.


Refurbishing rockets has costs (send the ship, refurb the rocket, and
reduced revenues when launching paylod on refurb rocket). Hopefully,
those are significantly lower than building new stage1.

The problem is that for mission profiles with high landing failure rate,
the cost of sending ship out and then having to repair it after
explosion for failed landings may outweight the cost advantage for those
missions that succeeded.

> Ditching in the ocean was tried before the barges were available. Every
> one was lost, even the ones that successfully "soft landed"

The idea being that if the risk of failure are high enough, you drop
rocket at sea and don't even bother to send ships out to watch it. (or
bother firing engines to make soft water landing.

Right now, SpaceX has to make all the attempst possible to calculate the
risks of success/failure and debug/fine tune the system.

But eventually, the R&D phase for landings and refurbishing will end and
the accountants will decide whether for high risk launches, it is worth
bothering with ships and trying to recuperate rocket.

Also, eventually, they will also get to know how many times a rocket can
be economically refurbiushed. So when a rocket has done that number of
launches, then why bother sending ships out when the rocket won't be
re-used ?

> At this point, reducing pressure on the manufacturing capacity is quite
> important, even if these first few re-flights don't "save" any money.

Selling more fur coats at $10 when they cost you $15 won't magically
make this profitable. In an R&D phase, you want as many launches as
possible to debug, test the limits etc. But eventually, the banks,
accountants will demand the endeavour make money and they then have to
take a cold hard look to see what sort of missions allow the
refurbishing to be profitable and which ones don't.

[Jeff Findley]

In article <57620c85$0$15612$c3e8da3$9dec...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-15 19:41, Jeff Findley wrote:
>
> > Possibly, but I doubt it. Out of the last three GTO missions (high
> > performance) they successfully landed two out of three. That's not bad,
>
> I agree. But it may turn out that after 10 such missions, only 2 will
> have succeeded. Or maybe 9. So too early to tell.

Agreed.

> The good news is that with every experience, they find another software
> "glitch" that they can fix to give the rocket wider range of conditions
> where it can land succesfully.

Also agreed. They'll fix what they can with the hardware and software
and keep flying.

> > high risk because they really are at the very edge of the
capabilities
> > of the stage.
>
> Exactly. But financial realities will dictate whether the failure rate
> for those "at the very limit" warrants even bothering to send a ship out
> to greet rocket. Let it ditch in water and build a new one.

I agree that's how it should be run. It all depends on the cost versus
potential benefit. Right now, Musk and the engineers really want to get
stages back for inspection, so they'll spend the money to send the barge
out even if the chances of recover are low. Later, when they better
understand the odds, is when they will have a better handle on what the
chances of recovery are for a given flight.

> Refurbishing rockets has costs (send the ship, refurb the rocket, and
> reduced revenues when launching paylod on refurb rocket). Hopefully,
> those are significantly lower than building new stage1.
>
> The problem is that for mission profiles with high landing failure rate,
> the cost of sending ship out and then having to repair it after
> explosion for failed landings may outweight the cost advantage for those
> missions that succeeded.

Agreed, in the long term. But for now, they'll spend the money even on
a slim recovery chance, because they still have a lot to learn from the
ones they do recover.

> > Ditching in the ocean was tried before the barges were available.
Every
> > one was lost, even the ones that successfully "soft landed"
>
> The idea being that if the risk of failure are high enough, you drop
> rocket at sea and don't even bother to send ships out to watch it. (or
> bother firing engines to make soft water landing.
>
> Right now, SpaceX has to make all the attempst possible to calculate the
> risks of success/failure and debug/fine tune the system.
>
> But eventually, the R&D phase for landings and refurbishing will end and
> the accountants will decide whether for high risk launches, it is worth
> bothering with ships and trying to recuperate rocket.
>
> Also, eventually, they will also get to know how many times a rocket can
> be economically refurbiushed. So when a rocket has done that number of
> launches, then why bother sending ships out when the rocket won't be
> re-used ?

Agreed, eventually.

> > At this point, reducing pressure on the manufacturing capacity is quite
> > important, even if these first few re-flights don't "save" any money.
>
> Selling more fur coats at $10 when they cost you $15 won't magically
> make this profitable. In an R&D phase, you want as many launches as
> possible to debug, test the limits etc. But eventually, the banks,
> accountants will demand the endeavour make money and they then have to
> take a cold hard look to see what sort of missions allow the
> refurbishing to be profitable and which ones don't.
>

I think we're in violent agreement. :-)

Some people have said that the space shuttle program never truly got out
of its test program, even though it was declared "operational" after
five official test flights. There were so few flights, statistically
speaking, that every flight found some new anomaly that at least needed
to be studied and documented. The first five official test flights
clearly weren't sufficient in this regard.

My guess is that with Falcon, it will take many years to transition from
test program mode (where you'll do nearly anything to try to recover a
first stage) to an operational mode where it's relatively easy to decide
that you need to write off a stage without even attempting recovery.

[Jeff Findley]

In article <njrt9k$hej$1...@dont-email.me>,
rgrego...@gmSPAMBLOACKail.com says...
>

> The LA Times is reporting today's landing attempt was unsuccessful:
>
> SpaceX launches two satellites, but drone ship landing is unsuccessful.
> http://www.latimes.com/business/la-fi-spacex-launch-20160614-snap-story.html
>
> Elon Musk Verified account

> ?@elonmusk

> Looks like thrust was low on 1 of 3 landing engines. High g landings v
> sensitive to all engines operating at max.
> https://twitter.com/elonmusk/status/743097337782763521
>
> My opinion, in order to land successfully in a consistent fashion SpaceX
> will have to give the F9 hovering ability.

SpaceX released a video showing how close this landing was. Apparantly
the stage ran out of LOX right above the deck. You'll want to take a
look because it actually looks very close to hovering in the video.

https://www.reddit.com/r/spacex/comments/4ogmvc/elon_musk_on_twitter_loo
ks_like_early_liquid/

[Fred J. McCall]

Jeff Findley <jfin...@cinci.nospam.rr.com> wrote:

>In article <njrt9k$hej$1...@dont-email.me>,
>rgrego...@gmSPAMBLOACKail.com says...
>>
>> The LA Times is reporting today's landing attempt was unsuccessful:
>>
>> SpaceX launches two satellites, but drone ship landing is unsuccessful.
>> http://www.latimes.com/business/la-fi-spacex-launch-20160614-snap-story.html
>
>Yes, but the launch *was* successful, so the paying customer is happy
>and the Falcon flight program will continue. :-)
>

Right. And since right now he's charging as if he's not going to get
the stages back, SpaceX is also happy (enough).

>
>> Elon Musk Verified account
>> ?@elonmusk
>> Looks like thrust was low on 1 of 3 landing engines. High g landings v
>> sensitive to all engines operating at max.
>> https://twitter.com/elonmusk/status/743097337782763521
>
>He also Tweeted that SpaceX has already been working on ways to handle
>this situation. In other words, it's just like the launch that "ran out
>of hydraulic fluid" for the grid fins. Even before that failure, they
>were working on increasing the fluid available for landings.
>

And even if they don't, if it works only part of the time they still
come out ahead as long as the cost of recovery and refurbishment is
lower than a new booster.

>> My opinion, in order to land successfully in a consistent fashion
>> SpaceX will have to give the F9 hovering ability.
>
>I respectfully disagree. Again, this is a known issue that was already
>being worked on. This is a *test flight program*. SpaceX has yet to
>even refly a stage! Problems are expected during a test flight program.
>You develop fixes for problems as they become known. In this case, the
>problem was already known and a fix was already in the works. This was
>not an "unknown unknown" this time. It was a known risk that they took
>in order to fly the mission for the customer without making them wait
>for a landing fix they largely don't care about.
>
>The customer just wants their satellites in the proper orbit. That
>mission was accomplished.
>

I agree with you. Not only would building in 'hover' for recovery
invalidate all the work they've already done (essentially start over
and crash some more until the landing software was right), but it
would require an expensive redesign of the engines. Since SpaceX can
already compete on price with the existing system, it's just not worth
the cost.

This is the problem with a lot of people who just think about 'theory'
and push for performance. They lose sight of the economics of the
thing.

>> High g landings are endemic to a "hover-slam" landing, more commonly
>> referred to as a "suicide-burn", more accurately referred to as "land or
>> slam", since without hovering ability, you only get one chance at it. You
>> either stick the landing on the first try, or you crash and burn.
>
>You only got one chance at final approach and landing a shuttle orbiter,
>but they were all successful (with arguably a few close calls). So
>that, in and of itself, doesn't disqualify the hover slam approach.
>Besides, the Falcon 9 first stage is unmanned, so nobody was killed.
>
>Remember, "perfect is the enemy of good enough". If they can make this
>"good enough", they can learn from it and incorporate all of the lessons
>learned in their next generation vehicle. Not everything has to be
>fixed in version 1.X of a vehicle. Version 1 just has to be "good
>enough". Version 2.0 can contain major upgrades and will hopefully be
>even better.
>

SpaceX essentially gets the recovered stages for 'free', since they
charge the customer as if the stage is going to be expended. There
are at least three different cost models that would allow SpaceX to
lower costs based on booster recovery. All of them work just fine
(given analysis of costs and recovery success rates) with an
'imperfect' percentage of successful recovery attempts.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

[Fred J. McCall]

Jeff Findley <jfin...@cinci.nospam.rr.com> wrote:

>In article <5761dc6e$0$29122$c3e8da3$3863...@news.astraweb.com>,
>jfmezei...@vaxination.ca says...
>>
>> On 2016-06-15 18:02, Jeff Findley wrote:
>>
>> > Remember, "perfect is the enemy of good enough". If they can make this
>> > "good enough", they can learn from it and incorporate all of the lessons
>> > learned in their next generation vehicle. Not everything has to be
>> > fixed in version 1.X of a vehicle. Version 1 just has to be "good
>> > enough". Version 2.0 can contain major upgrades and will hopefully be
>> > even better.
>>
>>
>> There is one issue not being mentioned: right now, they are testing the
>> limits of the vehicle.
>>
>> They may come to the conclusion that for high performance launches,
>> there is too much speed and not enough fuel to make a reliable landing.
>> Say they manage 50% of landings (for sake of discussion).
>
>Possibly, but I doubt it. Out of the last three GTO missions (high
>performance) they successfully landed two out of three. That's not bad,
>IMHO, considering how early in the test program it is and the fact that
>Musk has said repeatedly that these post GTO mission landings are very
>high risk because they really are at the very edge of the capabilities
>of the stage.
>

There will be missions where the size of the payload precludes
recovery (because you can't reserve the landing fuel and get the
performance the customer needs). They have a pretty good idea of
where that line is. For anything else, given the cost of building a
new stage, it is probably always going to be cheaper to try to recover
the stage than not even bother with the attempt. After all, you've
already paid for the recovery hardware ("Of Course I Still Love You")
and the staff required are still on salary, so the marginal cost of
attempting a recovery is low.

>
>> What is the cost of the attempted landing (drone ship, crews, helicopter
>> to video it etc) as well as the cost of repairing the drone ship after
>> the big explosion. Economics may dictate that for such flights, it is
>> best to ditch in ocean. Aka: value of 5 recovered rockets < then cost of
>> trying to land 10 rockets, and repairing damage from the 5 failed ones.
>
>Ditching in the ocean was tried before the barges were available. Every
>one was lost, even the ones that successfully "soft landed" on the ocean
>surface. They all broke apart due to wave action. There is a reason
>ships have very thick hulls. Liquid fueled launch vehicle stages do not
>have thick hulls. The solid fueled shuttle SRBs survived because they
>had very thick steel casings.
>

And even the SRBs required a lot of work before they could have been
reflown.

The only real 'delta cost' for recovery is the fuel to move the barge
(which you already own) plus flight hours on any aircraft (and you
don't HAVE to video the thing - SpaceX does that for the 'cool
factor', Musk recognizing that a lot of us geeks (like the ones he has
working for him) like to see it). Damage from an 'explosion' of the
stage to the landing ship is probably unlikely. Remember, these
things are designed to have firing rocket engines impinge on them.
Despite how flashy the explosion might be, that's probably tougher on
the landing ship than any uncontained explosion of a stage.

>
>> But we're not there yet because it is too soon to establish the
>> economics of landing the rocket.
>
>The economics of recovering and ref-lying a vehicle is a narrow view.
>Widen your view to the overall company's economics...
>
>At this point, reducing pressure on the manufacturing capacity is quite
>important, even if these first few re-flights don't "save" any money.
>Also, getting the stages back for inspections is a good thing. It
>allows for more engineering data than dropping it in the ocean and
>letting it sink, which is the alternative that every other current US
>launch vehicle provider uses.
>

Not only that, but as long as the cost of FUEL for the recovery
systems plus necessary refurbishment is less than the cost of
manufacturing a new stage, recovery is a big incremental economic win
regardless of which cost model(s) are used to recover the cost of
recovery.

Sorry, about all the 'recovery' in that statement, but I'm still in
recovery. :-)

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-15 19:41, Jeff Findley wrote:
>>
>> high risk because they really are at the very edge of the capabilities
>> of the stage.
>
>Exactly. But financial realities will dictate whether the failure rate
>for those "at the very limit" warrants even bothering to send a ship out
>to greet rocket. Let it ditch in water and build a new one.
>

But once you have the recovery ship (and you need it if you plan on
recovering any) and are paying the personnel involved, the incremental
cost of deploying for recovery is small. A new first stage costs
around $18 million.

>
>Refurbishing rockets has costs (send the ship, refurb the rocket, and
>reduced revenues when launching paylod on refurb rocket). Hopefully,
>those are significantly lower than building new stage1.
>

If you have reduced NET revenue when launching payload on a refurbed
rocket then you're doing it wrong. There might not be ANY reduced
revenue when launching on a refurbed rocket, depending on what the
reliability of refurbed stages is (and I wouldn't expect it to be
significantly worse than new).

>
>The problem is that for mission profiles with high landing failure rate,
>the cost of sending ship out and then having to repair it after
>explosion for failed landings may outweight the cost advantage for those
>missions that succeeded.
>

I doubt there's much 'repair' needed after a stage explosion. Let's
suppose that you only succeed in recovering 50%. The recovery ship
and personnel costs are already sunk costs, so the only real
incremental cost is the fuel to send the recovery stuff out and back.
Probably less than a million dollars. Assume it costs another million
dollars to refurb a stage.

So for 10 attempted recoveries, the total cost is around $15 million.
That's less than the cost of ONE new stage. And it's a 'savings' of
$90 million on building new stages, so the net is like $75 million. If
the success rate is worse the 'saving' go down, but so does the 'cost'
because I don't refurb stages I don't recover. Even if I only recover
10%, my net is like $7 million so it's still worth doing at the
margin.

Now, at some point my success rate could be so low that it's not worth
the fixed costs and I have no idea what those fixed costs amount to.

>
>>
>> Ditching in the ocean was tried before the barges were available. Every
>> one was lost, even the ones that successfully "soft landed"
>
>The idea being that if the risk of failure are high enough, you drop
>rocket at sea and don't even bother to send ships out to watch it. (or
>bother firing engines to make soft water landing.
>
>Right now, SpaceX has to make all the attempst possible to calculate the
>risks of success/failure and debug/fine tune the system.
>
>But eventually, the R&D phase for landings and refurbishing will end and
>the accountants will decide whether for high risk launches, it is worth
>bothering with ships and trying to recuperate rocket.
>
>Also, eventually, they will also get to know how many times a rocket can
>be economically refurbiushed. So when a rocket has done that number of
>launches, then why bother sending ships out when the rocket won't be
>re-used ?
>

If you're going to recover any, it's almost always going to be worth
attempting the recovery. Most of the costs of recovery are sunk
costs.

>
>> At this point, reducing pressure on the manufacturing capacity is quite
>> important, even if these first few re-flights don't "save" any money.
>
>Selling more fur coats at $10 when they cost you $15 won't magically
>make this profitable. In an R&D phase, you want as many launches as
>possible to debug, test the limits etc. But eventually, the banks,
>accountants will demand the endeavour make money and they then have to
>take a cold hard look to see what sort of missions allow the
>refurbishing to be profitable and which ones don't.
>

It's always worthwhile to attempt a recovery of any stage that has any
chance of recovery if you're going to maintain the infrastructure to
recover any of them. The only marginal costs are fuel for the ships,
which amounts to peanuts.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

[JF Mezei]

On 2016-06-18 07:30, Fred J. McCall wrote:

> There will be missions where the size of the payload precludes
> recovery (because you can't reserve the landing fuel and get the
> performance the customer needs).

There are obviuos cases where ditching stage 1 is happening, and there
are borderline cases. That "borderline" area right now is those GTO
launches.

> For anything else, given the cost of building a
> new stage, it is probably always going to be cheaper to try to recover
> the stage than not even bother with the attempt.

Accountants will decide this once SpaceX has enough data points and once
its software has matured. Right now, it appears there is still much
fine tuning of software possible. But once optimized to the max, they
will know pretty well what the limits are in terms of having enough fuel
to reliably land.

> After all, you've
> already paid for the recovery hardware ("Of Course I Still Love You")
> and the staff required are still on salary, so the marginal cost of
> attempting a recovery is low.

That is for accountants to decide. There is the cost of refurbishing the
barge after an explosion.

Also, the marginal cost of deploying vs leaving in port may not be so
small. If engines require maintenance based on hours of operation, then
the more you use it, the most it costs to maintain. And while crews are
at sea, they may cost much more than on land (meals, overtime etc). It
is also not clear whether SpaceX owns the support ships that we never
see or whether it leases them "on demand".

Accountants would have such numbers by now. (including cost of refurb
after landing failure).

And if the cost of refurbishing the barge is high, accountants may ask
engineers to have rocket decide whether landing is possible or not (fuel
remaining vs speed/altitude) or have the software wilfully ditch next to
the barge if it thinks it can't make a safe landing due to insufficient
fuel.

> And even the SRBs required a lot of work before they could have been
> reflown.

SRBs landed in salt water.

Nobody is suggesting refurbishing a stage1 that falls flat on its belly
in the ocean.


With regards to revenues for flights on new rockets, it would not
surprise me if negotiations included a rebate if stage1 is recovered.
(or recoverable because of easier flight profile).

[JF Mezei]

On 2016-06-18 11:47, Fred J. McCall wrote:

> If you have reduced NET revenue when launching payload on a refurbed
> rocket then you're doing it wrong. There might not be ANY reduced
> revenue when launching on a refurbed rocket, depending on what the
> reliability of refurbed stages is

We can turn this around: if NASA demands new stages for the flights it
buys, SpaceX can charge a premium for that. Hence more revenues.

Once reliability of refurb engines is proven and even NASA doesn't
demand new stages for its flights, then yeah, the price to launch will
not be affected by whether a stage is reused or not.

And one has to consider the possibility that a "new" stage may have half
its engines new and half used.

> I doubt there's much 'repair' needed after a stage explosion.

Accountants know, we don't.

> Now, at some point my success rate could be so low that it's not worth
> the fixed costs and I have no idea what those fixed costs amount to.

But this applies on a mission profile basis. Some types of missions
would have higher reliable landings, while others have too high a risk
of explosion to bother trying to recover. And SpaceX doesn't yet have
enough data poimts to draw such a line.

And for now, they try all of them to establish those data points and
fine tune the software to move that line even higher to be able to
recover more of the stages.

> It's always worthwhile to attempt a recovery of any stage that has any
> chance of recovery if you're going to maintain the infrastructure to
> recover any of them.

It depends on how much its costs to refurbish the stage. Something which
SpaceX hasn't done yet.

Remember that the shuttle was originally pitched as requiring little
maintance between flights, but turned out differently.

[Greg (Strider) Moore]

"Fred J. McCall" wrote in message
news:3ibamb126trss48sb...@4ax.com...

>
>The only real 'delta cost' for recovery is the fuel to move the barge
>(which you already own) plus flight hours on any aircraft (and you
>don't HAVE to video the thing - SpaceX does that for the 'cool
>factor', Musk recognizing that a lot of us geeks (like the ones he has
>working for him) like to see it). Damage from an 'explosion' of the
>stage to the landing ship is probably unlikely. Remember, these
>things are designed to have firing rocket engines impinge on them.
>Despite how flashy the explosion might be, that's probably tougher on
>the landing ship than any uncontained explosion of a stage.

Yeah, someone I was talking to suggested that an explosion might cause a lot
of damage, but I tend to doubt it.

You already have a pretty solid deck built for the Falcon 9 to "crash" onto
and it's built to withstand an engine blast.

So sure, maybe a handrail or two and maybe a camera, but as long as you're
hitting the deck, my guess is most of the effort is sweeping the debris off
after.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-18 07:30, Fred J. McCall wrote:
>
>> There will be missions where the size of the payload precludes
>> recovery (because you can't reserve the landing fuel and get the
>> performance the customer needs).
>
>There are obviuos cases where ditching stage 1 is happening, and there
>are borderline cases. That "borderline" area right now is those GTO
>launches.
>

Wrong. It is always worthwhile to try to recover a stage if there is
ANY chance of recovery.

>
>> For anything else, given the cost of building a
>> new stage, it is probably always going to be cheaper to try to recover
>> the stage than not even bother with the attempt.
>
>Accountants will decide this once SpaceX has enough data points and once
>its software has matured. Right now, it appears there is still much
>fine tuning of software possible. But once optimized to the max, they
>will know pretty well what the limits are in terms of having enough fuel
>to reliably land.
>

They pretty well know that now.

>> After all, you've
>> already paid for the recovery hardware ("Of Course I Still Love You")
>> and the staff required are still on salary, so the marginal cost of
>> attempting a recovery is low.
>
>That is for accountants to decide. There is the cost of refurbishing the
>barge after an explosion.
>

I seriously doubt that's a big cost because I seriously doubt an
uncontained explosion on a landing pad is going to damage anything
other than some surface mounted support equipment.

>
>Also, the marginal cost of deploying vs leaving in port may not be so
>small. If engines require maintenance based on hours of operation, then
>the more you use it, the most it costs to maintain. And while crews are
>at sea, they may cost much more than on land (meals, overtime etc). It
>is also not clear whether SpaceX owns the support ships that we never
>see or whether it leases them "on demand".
>

Engine maintenance on a ship is, relatively speaking, pretty damned
cheap. Keeping it in port costs money in port fees. There aren't a
lot of people involved, so paying and feeding them is down in the
noise. There is only one other ship involved.

Again, if there is even a 10% chance of recovery attempting the
recovery is a 'win'.

>
>Accountants would have such numbers by now. (including cost of refurb
>after landing failure).
>

Well, no, they won't. This hasn't been done enough and a refurbed
booster has never been reflown.

>
>And if the cost of refurbishing the barge is high, accountants may ask
>engineers to have rocket decide whether landing is possible or not (fuel
>remaining vs speed/altitude) or have the software wilfully ditch next to
>the barge if it thinks it can't make a safe landing due to insufficient
>fuel.
>

So you take all the expense of a recovery and then toss $18 million in
the water. Makes no sense.

>
>>
>> And even the SRBs required a lot of work before they could have been
>> reflown.
>>
>
>SRBs landed in salt water.
>

Which was irrelevant. Just the impact messed them up, which is what
was being discussed. Salt water doesn't hurt an SRB casing all that
much, given that there's no engine in there that you're trying to
recover.

>
>Nobody is suggesting refurbishing a stage1 that falls flat on its belly
>in the ocean.
>

Nobody sane is suggesting trying to recover a stage from the water,
period. You can't get them down soft enough.

>
>With regards to revenues for flights on new rockets, it would not
>surprise me if negotiations included a rebate if stage1 is recovered.
>(or recoverable because of easier flight profile).
>

That's certainly one funding model that could be used. I can think of
several others that could all be used independently or in combination.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-18 11:47, Fred J. McCall wrote:
>>
>> If you have reduced NET revenue when launching payload on a refurbed
>> rocket then you're doing it wrong. There might not be ANY reduced
>> revenue when launching on a refurbed rocket, depending on what the
>> reliability of refurbed stages is
>>
>
>We can turn this around: if NASA demands new stages for the flights it
>buys, SpaceX can charge a premium for that. Hence more revenues.
>

That's the same thing and if you're getting lower NET revenue for
reflown stages then you are doing it wrong.

>
>Once reliability of refurb engines is proven and even NASA doesn't
>demand new stages for its flights, then yeah, the price to launch will
>not be affected by whether a stage is reused or not.
>

Do you know what NET means?

>
>And one has to consider the possibility that a "new" stage may have half
>its engines new and half used.
>

Why the hell would they do that? The idea is to not have to take the
stage apart like that.

>
>> I doubt there's much 'repair' needed after a stage explosion.
>
>Accountants know, we don't.
>

Accountants don't know shit.

>
>>
>> Now, at some point my success rate could be so low that it's not worth
>> the fixed costs and I have no idea what those fixed costs amount to.
>>
>
>But this applies on a mission profile basis. Some types of missions
>would have higher reliable landings, while others have too high a risk
>of explosion to bother trying to recover. And SpaceX doesn't yet have
>enough data poimts to draw such a line.
>

Do you know what "fixed costs" mean? Fixed costs are costs that are
FIXED regardless of what you do.

>
>And for now, they try all of them to establish those data points and
>fine tune the software to move that line even higher to be able to
>recover more of the stages.
>

You really don't understand what's going on and you don't seem willing
to listen when someone tries to tell you.

>
>>
>> It's always worthwhile to attempt a recovery of any stage that has any
>> chance of recovery if you're going to maintain the infrastructure to
>> recover any of them.
>>
>
>It depends on how much its costs to refurbish the stage. Something which
>SpaceX hasn't done yet.
>

Non sequitur. Go back and read what I said.

>
>Remember that the shuttle was originally pitched as requiring little
>maintance between flights, but turned out differently.
>

Yeah, it was pitched that way WHEN IT WAS AN INITIAL DESIGN CONCEPT.
Nobody believed that by the time they had the final design.

Falcon 9 isn't a 'paper bird'. It's flying hardware.

[JF Mezei]

On 2016-06-19 11:45, Fred J. McCall wrote:

> Non sequitur. Go back and read what I said.

Your assumptions are based on sending the barge to a failed landing and
refurbiushing it after the explosion being minimal costs.

My statement is that only accountants know this now. They have
experience in how much it costs to run the barge and support ship, and
they have had a few crashes to know what sort of damage is involved and
how many man hours/equipment this costs.

Elon Musk in an interveiw a while back even admitted that they don't yet
have all the numbers and enough data points to know whether refurbishing
will be good business.

Note that yesterday, he tweeted that he now expects 70% of landings to
be succesful. But IF those statistics were broken down to 95% of
ISS/LEO meissions being succesful and only 30% of GTO missions being
successful, you can see that this would affect whether they bother
trying to recover GTO missions to begin with.

I am not stating that they should or shouldn't bother. What I am saying
is that they need to have statistics on how each type of mission affects
recovery chances and run the numbers to see if this is a paying
proposition in the long term.

(and to get those numbers, they have to try as many landings as possible
which is what they are doing now.) Hopefully it does turn out that the
costs are low enough and success rate is high enough that they try to
recover all of them. But they don't have enough numbers yet, and since
the software is still evolving, the cutover between reliable landing and
unreliable landing is also moving to include more "reliable" landings.

> Falcon 9 isn't a 'paper bird'. It's flying hardware.

The landing part is still very much R&D. And the refurbishing of the
stage 1 is also R&D.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-19 11:45, Fred J. McCall wrote:
>
>> Non sequitur. Go back and read what I said.
>
>Your assumptions are based on sending the barge to a failed landing and
>refurbiushing it after the explosion being minimal costs.
>

I note that when called on a non sequitur response, your 'answer' is
to start snipping out context. Cost of sending the barge is DIESEL
FUEL. That's pretty much down in the noise. Have you LOOKED at one
of these barges? Just what do you think there is for an explosion to
damage? There are two cargo containers with 'support equipment'.
That's it.

>
>My statement is that only accountants know this now. They have
>experience in how much it costs to run the barge and support ship, and
>they have had a few crashes to know what sort of damage is involved and
>how many man hours/equipment this costs.
>

A lot of these numbers are public or easily inferred.

>
>Elon Musk in an interveiw a while back even admitted that they don't yet
>have all the numbers and enough data points to know whether refurbishing
>will be good business.
>

The expectation is that they won't have to 'refurbish' anything. Just
inspect and refly.

>
>Note that yesterday, he tweeted that he now expects 70% of landings to
>be succesful. But IF those statistics were broken down to 95% of
>ISS/LEO meissions being succesful and only 30% of GTO missions being
>successful, you can see that this would affect whether they bother
>trying to recover GTO missions to begin with.
>

Why?

>
>I am not stating that they should or shouldn't bother. What I am saying
>is that they need to have statistics on how each type of mission affects
>recovery chances and run the numbers to see if this is a paying
>proposition in the long term.
>
>(and to get those numbers, they have to try as many landings as possible
>which is what they are doing now.) Hopefully it does turn out that the
>costs are low enough and success rate is high enough that they try to
>recover all of them. But they don't have enough numbers yet, and since
>the software is still evolving, the cutover between reliable landing and
>unreliable landing is also moving to include more "reliable" landings.
>

Well, doh!

>
>> Falcon 9 isn't a 'paper bird'. It's flying hardware.
>
>The landing part is still very much R&D. And the refurbishing of the
>stage 1 is also R&D.
>

Non sequitur. But you cut all the context.

The idea is that you don't need to 'refurbish' the stages. You do a
quick inspection and then refly them.


--
"Ignorance is preferable to error, and he is less remote from the
truth who believes nothing than he who believes what is wrong."
-- Thomas Jefferson

[JF Mezei]

On 2016-06-20 13:56, Fred J. McCall wrote:

> A lot of these numbers are public or easily inferred.

So, SpaceX accounting is public ?

> The expectation is that they won't have to 'refurbish' anything. Just
> inspect and refly.

NASA had the same expectation with the Shuttle too. I don't believe Musk
as released any info on what's needed to get a landed Stage1 ready to
fly again. And I suspect they want a few more samples back before
drawing conclusions, so your conclusion that it is just "inspect and
refly" is premature.

It may end up as "inspect and refly". But until there is enough
experience, nobody can draw that conclusion.

> The idea is that you don't need to 'refurbish' the stages. You do a
> quick inspection and then refly them.

At the moment, this is the dream. Whether that becomes reality depends
on the outcome of the tests being done with recent launches where a
stage was recovered.

One issue is that they may find a stage to be fine and "inspect and
refly" is decided but at launch, something goes wrong and they realise
they forgot to inspect X for Y type of damage. That will come with
experience.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-20 13:56, Fred J. McCall wrote:
>
>> A lot of these numbers are public or easily inferred.
>
>So, SpaceX accounting is public ?
>

Read what I said, yammerhead.

OK, I'm going to type what follows REALLY SLOWLY. Read each sentence
and actually think about it until you understand what I've said.

>
>> The expectation is that they won't have to 'refurbish' anything. Just
>> inspect and refly.
>
>NASA had the same expectation with the Shuttle too.
>

False. NASA had no such expectation for anything that even
approximated the vehicle that they actually built. The original
Shuttle concept was for a much smaller vehicle with much less
crossrange capability. That concept never got much beyond that stage.
THAT concept was the one NASA had the low refurbishment estimates for.
They NEVER had a 'zero refurbishment' expectation and they certainly
never had it for the vehicle they actually designed and built.
Claiming that they did is A LIE.

Learn something about the actual development history of the Space
Shuttle.

>
>I don't believe Musk
>as released any info on what's needed to get a landed Stage1 ready to
>fly again. And I suspect they want a few more samples back before
>drawing conclusions, so your conclusion that it is just "inspect and
>refly" is premature.
>
>It may end up as "inspect and refly". But until there is enough
>experience, nobody can draw that conclusion.
>

With SpaceX we're talking about REAL HARDWARE. That hardware, unlike
the Space Shuttle, was designed around the idea that it could be
reflown around ten times with little to no refurbishment. SpaceX has
dismantled and inspected the first booster they recovered. They have
stated that it all looks clean and virtually brand new.

Learn something about what SpaceX is saying.

>
>>
>> The idea is that you don't need to 'refurbish' the stages. You do a
>> quick inspection and then refly them.
>>
>
>At the moment, this is the dream. Whether that becomes reality depends
>on the outcome of the tests being done with recent launches where a
>stage was recovered.
>

No. At the moment, this is the intended design goal. All evidence to
date indicates that design goal is being met.

Again, learn something about what SpaceX is saying.

>
>One issue is that they may find a stage to be fine and "inspect and
>refly" is decided but at launch, something goes wrong and they realise
>they forgot to inspect X for Y type of damage. That will come with
>experience.
>

And fairies may shit magic dust all over things and make it all fail.

Again, learn something about what SpaceX is saying.

[JF Mezei]

On 2016-06-20 17:30, Fred J. McCall wrote:

> No. At the moment, this is the intended design goal. All evidence to
> date indicates that design goal is being met.

Evidence based on 1 recovered stage 1. You are stating that the design
goal is being met based on that 1 point of data. I am stating it is too
early to state that it is being met.

You state that it can be reflow 10 times. I say that until they have
take a stage and reflown it multiple times, it is too early to say how
many times a stage can economically be reflown. ( refurb costs may
increase with number of flights for instance).

[Vaughn Simon]

On 6/20/2016 5:30 PM, Fred J. McCall wrote:
> SpaceX has
> dismantled and inspected the first booster they recovered. They have
> stated that it all looks clean and virtually brand new.

Yet curiously SpaceX hasn't yet static test fired any recovered
boosters. I know that SpaceX is busy trying to increase their launch
tempo (and having considerable success) but this delay really is
starting to get curious, particularly in the face of their success at
recovery. Their stated goal was to static fire a recovered booster
several times, and to do it quickly. It hasn't happened. Why not?

[Jeff Findley]

In article <57687133$0$35688$b1db1813$6557...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-20 17:30, Fred J. McCall wrote:
>
> > No. At the moment, this is the intended design goal. All evidence to
> > date indicates that design goal is being met.
>
> Evidence based on 1 recovered stage 1. You are stating that the design
> goal is being met based on that 1 point of data. I am stating it is too
> early to state that it is being met.

SpaceX has recovered more than one stage. They've recovered four so
far. Here is an article with a picture showing all four (the one on the
right has been cleaned up a bit, but you can still see some of the soot
at the top end of the stage).

http://www.space.com/33102-spacex-leaning-rocket-comes-ashore-
photos.html

> You state that it can be reflow 10 times. I say that until they have
> take a stage and reflown it multiple times, it is too early to say how
> many times a stage can economically be reflown. ( refurb costs may
> increase with number of flights for instance).

They've done extensive tests of the Merlin engines, which should be the
"long pole in the tent" when it comes to reflights without
refurbishment. I'm betting they'll meet that 10 flights without
refurbishment goal. Perhaps not right away, but given enough time.

[Jeff Findley]

In article <nka0b4$p0l$1...@gioia.aioe.org>, vaugh...@gmail.com says...

>
> On 6/20/2016 5:30 PM, Fred J. McCall wrote:
> > SpaceX has
> > dismantled and inspected the first booster they recovered. They have
> > stated that it all looks clean and virtually brand new.
>
> Yet curiously SpaceX hasn't yet static test fired any recovered
> boosters.

Actually, they did in January:

SpaceX fire up returned Falcon 9 first stage at SLC-40
January 15, 2016 by Chris Bergin
https://www.nasaspaceflight.com/2016/01/spacex-fire-up-falcon-9-first-
stage-slc-40/

> I know that SpaceX is busy trying to increase their launch
> tempo (and having considerable success) but this delay really is
> starting to get curious, particularly in the face of their success at
> recovery. Their stated goal was to static fire a recovered booster
> several times, and to do it quickly. It hasn't happened. Why not?

I'm betting it's the huge backlog of launches to take care of. Paying
customers no doubt come first.

[Fred J. McCall]

And I'm stating that you are a fool and wasting my time.

[Fred J. McCall]

Because they're busy. Nothing 'curious' about that.

[JF Mezei]

On 2016-06-20 21:55, Jeff Findley wrote:

> SpaceX has recovered more than one stage. They've recovered four so
> far.

If the first one that was recovered isn't the one which will fly first,
it means that it isn't really flyiable without refurb if another stage
is in a better condition.

I have no problem with SpaceX taking its time to examine things. But the
fact that no a single stage has been designated for a reflight yet means
nobody should be making claims that "it'd a proven technology, it will
be able to fly 10 times without refurb" etc etc.

Just because there is higher degree of confindece that what SpaceX does
will happen (as opposed to NASA) doesn't mean that it is a done deal at
this point in time.


Since this is all new stuff, SpaceX has to develop validation tests for
those inspections. I am sure it os far mroe involved than looking at the
stage with a flashlight and using some Palmolive and s sponge to clean
off some burn marks.

Consider the one that landed "leaning". If landing was hard enough to
cause a leg to crumple, they probably have to do more expensive tests to
ensure the rest of the stack is fine since the other legs transfered the
full force of landing.

And I would suspect that for each flight, they would have high speed
video of launch and several phases to detect any anomalies. Say they saw
something strange on takeoff, but stack landed fine. They will still
want to investigate.


In fact, the crumpled leg one is likely a good candidate to help develop
inspection/testing procedures since the likelyhood of something being
broken is higher on that one.

[JF Mezei]

On 2016-06-20 21:59, Jeff Findley wrote:

> I'm betting it's the huge backlog of launches to take care of. Paying
> customers no doubt come first.

Would it be correct to state that production of new stage1s has been
"productized" and is now running smoothly ? If they need to increase
production rate, then it is a matter of duplicating machines and
employees. Easier said than done, but folks like Boeing, Airbus increase
production rates routinely.

Would it be correct to state that recovery, inspection and attempts at
relaunch of used stage1s would be an R&D effort that would operate
separately from the production line ?

If so, it would not be impacted by attempts at increasing production of
new parts for stage1.

However, budgets may be such that the R?D for reflight is limited
because not so strategically important/urgent. or maybe they reaslize it
is more work tnan they had thought.

Wher I can see some impact with production is in inspecting the landed
stages, they discover some part that is damaged and then tell production
folks to strenghten that part. (and then wait for that stage with
improve part to land so they can inspect it and perhaps use that one for
first reflight).

There are too many possibilities to draw any conclusions on this.

[Jeff Findley]

In article <5768d162$0$15575$c3e8da3$9dec...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-20 21:55, Jeff Findley wrote:
>
> > SpaceX has recovered more than one stage. They've recovered four so
> > far.
>
> If the first one that was recovered isn't the one which will fly first,
> it means that it isn't really flyiable without refurb if another stage
> is in a better condition.

Wrong. The first one is special, because it was first! It will
eventually go back to their headquarters in California to be permanently
displayed. Considering the amount of flown space vehicles in museums,
this is not at all surprising.

> I have no problem with SpaceX taking its time to examine things. But the
> fact that no a single stage has been designated for a reflight yet means
> nobody should be making claims that "it'd a proven technology, it will
> be able to fly 10 times without refurb" etc etc.

It should. There is nothing fundamental about a liquid fueled rocket
stage from an orbital launch vehicle that prevents reuse. It's just
that no one has *tried* all that hard to reuse one, until now.

Advocates of reusable launch vehicle tech have known this since the days
of the X-15 (earlier if you want to count the German rocket powered
fighter experience). It was rocket powered and the three copies which
were built flew so many times, I can never remember exactly how many
flights were made. Between then and now, engines have been repeatedly
fired on the test stand to test and qualify them. There is no
fundamental problem here that needs solving.

> Just because there is higher degree of confindece that what SpaceX does
> will happen (as opposed to NASA) doesn't mean that it is a done deal at
> this point in time.

You're allowed to be a bit skeptical, but at the same time, there really
isn't much reason for it. A SpaceX first stage has to perform several
burns just to complete it's primary mission, then kill horizontal
velocity, then reentry burn, then landing burn. That's already
demonstrating several rapid restarts in the time span of a few minutes!

> Since this is all new stuff, SpaceX has to develop validation tests for
> those inspections. I am sure it os far mroe involved than looking at the
> stage with a flashlight and using some Palmolive and s sponge to clean
> off some burn marks.

What "new stuff"? Visual inspections? Validation firings on a test
stand? What do you expect them to do between flights?

> Consider the one that landed "leaning". If landing was hard enough to
> cause a leg to crumple, they probably have to do more expensive tests to
> ensure the rest of the stack is fine since the other legs transfered the
> full force of landing.

Possibly, but I doubt it since that's what the crushable inner core is
supposed to do. It wasn't unexpected at all.

> And I would suspect that for each flight, they would have high speed
> video of launch and several phases to detect any anomalies. Say they saw
> something strange on takeoff, but stack landed fine. They will still
> want to investigate.

Certainly, but if there had been a significant problem during that main
burn, there would not have been enough fuel left for a landing in the
first place. The landing fuel would have been burnt to make up for any
performance shortfall during the main burn to put the second stage and
payload on the right trajectory. So a successful primary mission is a
very good indicator that nothing serious went wrong.

> In fact, the crumpled leg one is likely a good candidate to help develop
> inspection/testing procedures since the likelyhood of something being
> broken is higher on that one.

Again, possibly. But, pressurized tanks, which make up most of the
structure of the stage, are really freaking strong. As long as they
don't rupture, the stage as a whole is very likely o.k. I'm sure SpaceX
has done analysis and possibly even ground testing for this case and
already know what to expect. No, analysis and ground testing aren't a
replacement for flight testing, but this assumption that a stage might
be bad just because it's been to space and back is ludicrous.

Go re-read the history of the X-15. It was *always* expected it could
be reflown, barring a very hard landing because that was the case with
every aircraft before it! And even in the case of a hard landing, it
could be torn down and repaired. In all the flights of the X-15, only
one was permanently lost because it broke up and was destroyed during
flight.

Somehow, the launch vehicle guys in both the US and U.S.S.R. got a free
pass to ignore all of that experience with rocket engines and flight
vehicles and clung to the mistaken belief that launch vehicles must be
expendable simply because they started their engineering work with
missiles instead of aircraft. Madness. Simply madness.

It's mind boggling to think that it's taken the better part of a century
to start to meaningfully reverse that wrong headed thinking that never
should have existed in the first place.

[Jeff Findley]

In article <5768d3cb$0$22630$b1db1813$1459...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-20 21:59, Jeff Findley wrote:
>
> > I'm betting it's the huge backlog of launches to take care of. Paying
> > customers no doubt come first.
>
>
> Would it be correct to state that production of new stage1s has been
> "productized" and is now running smoothly ? If they need to increase
> production rate, then it is a matter of duplicating machines and
> employees. Easier said than done, but folks like Boeing, Airbus increase
> production rates routinely.

Sure, but that sort of capital investment costs a lot of money. Better
to reuse vehicles you've got than build new ones needlessly.

> Would it be correct to state that recovery, inspection and attempts at
> relaunch of used stage1s would be an R&D effort that would operate
> separately from the production line ?

Most likely, but they would both share engineering, ground test, and
launch resources. SpaceX isn't building an entire spaceport in Texas
just for fun.

> If so, it would not be impacted by attempts at increasing production of
> new parts for stage1.

Nope. Building new stages is just one part of the overall process. The
rest is shared between new and flown stages.

> However, budgets may be such that the R?D for reflight is limited
> because not so strategically important/urgent. or maybe they reaslize it
> is more work tnan they had thought.

It's limited by their orbital flight rate, since at this point in time
the test program is to recover and refly stages from actual orbital
missions. SpaceX has gone well beyond the realm of analysis and ground
test to the point that needlessly performing additional ground tests (on
unflown stages) just adds costs and generates little to no useful data.

> Wher I can see some impact with production is in inspecting the landed
> stages, they discover some part that is damaged and then tell production
> folks to strenghten that part. (and then wait for that stage with
> improve part to land so they can inspect it and perhaps use that one for
> first reflight).
>
> There are too many possibilities to draw any conclusions on this.

Yes, they'll find problems and fix them. That's a given. But to
timidly assume that vehicles are bad just because they've flown to space
and back is silly, especially since they've been designed from the
beginning to do just that.

Somehow we've lost our "guts". There are streets at Edwards Air Force
Base named after men who weren't afraid to climb into a flown vehicle
(many powered by rocket engines) and fly it again. Their names on the
streets were proof that this wasn't always successful. But, it is also
proof that they believed so strongly in advancing the state of the art
of aviation technology that they literally put their own lives on the
line in order to do it.

Why in the hell have we become so risk averse and timid? At times this
disgusts me, since it greatly limits progress.

Rand Simberg wrote a book about this very issue:

Safe Is Not an Option Paperback ? October 31, 2013
by Rand E. Simberg (Author), William Simon (Editor), Ed Lu (Foreword)
https://www.amazon.com/Safe-Not-Option-Rand-Simberg/dp/0989135519

[Vaughn Simon]

On 6/20/2016 9:59 PM, Jeff Findley wrote:
>> Yet curiously SpaceX hasn't yet static test fired any recovered
>> > boosters.
> Actually, they did in January:
>
> SpaceX fire up returned Falcon 9 first stage at SLC-40
> January 15, 2016 by Chris Bergin
> https://www.nasaspaceflight.com/2016/01/spacex-fire-up-falcon-9-first-
> stage-slc-40/
>

Thank you, I remember that now! But that is still far different from
the test they proposed, which I believe was supposed to be ten firings
to demonstrate the robustness of the booster. The article only mentions
one 2-second burn, and a questionable engine.

Incidentally it was also supposed to be done at their new pad, but with
the new "bleeding edge" super cooling equipment and procedures, I can
see where that may have slipped.

[Greg (Strider) Moore]

"Fred J. McCall" wrote in message

news:s1chmbp5reuqmqdrv...@4ax.com...

>
>
>And I'm stating that you are a fool and wasting my time.
>
>

You know Fred, unless you've got a gig I'm not aware of and getting paid for
this, you're under no obligation to respond to JF.
So he's not wasting your time. You are. You can stop responding to him any
time you want.

[Greg (Strider) Moore]

"Jeff Findley" wrote in message
news:MPG.31d2dc7ea...@news.eternal-september.org...

>
>Advocates of reusable launch vehicle tech have known this since the days
>of the X-15 (earlier if you want to count the German rocket powered
>fighter experience). It was rocket powered and the three copies which
>were built flew so many times, I can never remember exactly how many
>flights were made.

199. I always remember that because they were 1 short of 200 and did try for
it, but couldn’t get the conditions and everything in order before the money
finally ran out.

Jenkins (no surprise) has a good book on the X-15.

>Jeff

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-20 21:55, Jeff Findley wrote:
>>
>> SpaceX has recovered more than one stage. They've recovered four so
>> far.
>>
>
>If the first one that was recovered isn't the one which will fly first,
>it means that it isn't really flyiable without refurb if another stage
>is in a better condition.
>

It means no such thing. What it means is that SpaceX completely
dismantled it to see if the design goal was being met.

Read what SpaceX is saying.

>
>I have no problem with SpaceX taking its time to examine things. But the
>fact that no a single stage has been designated for a reflight yet means
>nobody should be making claims that "it'd a proven technology, it will
>be able to fly 10 times without refurb" etc etc.
>

You need to learn to read.

Read what I actually said.

Read what SpaceX is saying.

>
>Just because there is higher degree of confindece that what SpaceX does
>will happen (as opposed to NASA) doesn't mean that it is a done deal at
>this point in time.
>

Still puling out your NASA lie, I see.

>
>Since this is all new stuff, SpaceX has to develop validation tests for
>those inspections. I am sure it os far mroe involved than looking at the
>stage with a flashlight and using some Palmolive and s sponge to clean
>off some burn marks.
>

I doubt they have to 'develop' anything. Presumably they already have
acceptance criteria for new stages. Those should work just fine as
acceptance criteria for used stages.

>
>Consider the one that landed "leaning". If landing was hard enough to
>cause a leg to crumple, they probably have to do more expensive tests to
>ensure the rest of the stack is fine since the other legs transfered the
>full force of landing.
>

Despite having it explained to you multiple times and eventually
claiming you understood it, you're back to making silly statements.
The leg didn't 'crumple'. The crush core collapsed just like it is
designed to do. There is no 'transferred force' from the landing leg
to the stage itself for ANY leg. And there is no 'stack'; it's a
single stage.

Read what people explain to you or stop wasting their time.

Read what SpaceX is saying.

>
>And I would suspect that for each flight, they would have high speed
>video of launch and several phases to detect any anomalies. Say they saw
>something strange on takeoff, but stack landed fine. They will still
>want to investigate.
>

And if unicorns come and shit rainbow dust all over things they will
no doubt want to investigate.

>
>In fact, the crumpled leg one is likely a good candidate to help develop
>inspection/testing procedures since the likelyhood of something being
>broken is higher on that one.
>

Wrong. You still don't understand how the landing legs work.

Read what people explain to you and stop wasting their time.

Read what SpaceX says.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-20 21:59, Jeff Findley wrote:
>>
>> I'm betting it's the huge backlog of launches to take care of. Paying
>> customers no doubt come first.
>>
>
>Would it be correct to state that production of new stage1s has been
>"productized" and is now running smoothly ? If they need to increase
>production rate, then it is a matter of duplicating machines and
>employees. Easier said than done, but folks like Boeing, Airbus increase
>production rates routinely.
>

Have you ever worked for Boeing or Airbus? Are you aware that rockets
are HAND BUILT, so increasing production requires acquiring new
workforce and bringing them up to adequate skill levels?

>
>Would it be correct to state that recovery, inspection and attempts at
>relaunch of used stage1s would be an R&D effort that would operate
>separately from the production line ?
>

No.

>
>If so, it would not be impacted by attempts at increasing production of
>new parts for stage1.
>
>However, budgets may be such that the R?D for reflight is limited
>because not so strategically important/urgent. or maybe they reaslize it
>is more work tnan they had thought.
>
>Wher I can see some impact with production is in inspecting the landed
>stages, they discover some part that is damaged and then tell production
>folks to strenghten that part. (and then wait for that stage with
>improve part to land so they can inspect it and perhaps use that one for
>first reflight).
>
>There are too many possibilities to draw any conclusions on this.
>

Only if you're stupid.

Learn to read and read what people are telling you.

[Fred J. McCall]

"Greg \(Strider\) Moore" <moo...@deletethisgreenms.com> wrote:

>"Fred J. McCall" wrote in message
>news:s1chmbp5reuqmqdrv...@4ax.com...
>>
>>And I'm stating that you are a fool and wasting my time.
>>
>
>You know Fred, unless you've got a gig I'm not aware of and getting paid for
>this, you're under no obligation to respond to JF.
>So he's not wasting your time. You are. You can stop responding to him any
>time you want.
>

I always like to give them a chance before I shitcan them as
worthless, Greg. That's the explanation for why I still respond to
shite like this from you, as well.


--
"Then tomorrow we may all be dead. But how is that different
from every other day?"
-- Morpheus

[Rick Jones]

In sci.space.policy Jeff Findley <jfin...@cinci.nospam.rr.com> wrote:
> They've done extensive tests of the Merlin engines, which should be
> the "long pole in the tent" when it comes to reflights without
> refurbishment.

Would the next pole be the welds in the plumbing, followed by
structure?

rick jones
--
I don't interest myself in "why." I think more often in terms of
"when," sometimes "where;" always "how much." - Joubert
these opinions are mine, all mine; HPE might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

[JF Mezei]

On 2016-06-21 06:09, Jeff Findley wrote:

> It should. There is nothing fundamental about a liquid fueled rocket
> stage from an orbital launch vehicle that prevents reuse. It's just
> that no one has *tried* all that hard to reuse one, until now.

And there is nothing fundamental about jet engines to prevent reuse. And
this is done every day by jetliners.

HOWEVER, the airlines and FAA learned via experience that jet engines
can only run so many hours before needing certain level of inspection,
and after another set of hours, require a heavy maintenance check.

Oh, and after a "hard" landing, the aircraft needs a maintenance check.

So SpaceX will learn via experience how many times a stage can be
reflown with just a flashlight inpection, how hard a landing the stage
can take without needing more serious inspection and after how many
flights is a major inspection required (and whether such major
maintenance is economic or not).

When you look at the Orbital ATK fireworks at Wallops, didn't they run
the engines to test them before ? All seemed fine and yet, engines failed.

Doing a flight test (including landing) of engines 10 times is cool. But
you really need to test until they fail. There is a big difference if
they fail on the 11th simulation vs on the 25th simulation. (on the
25th, it means that when you fly the 10th flight, the engines are still
far from failure).

> fired on the test stand to test and qualify them. There is no
> fundamental problem here that needs solving.

It is a question of validating the predictions. They've weeded out the
problems they know about. They haven't weeded out problems they don't
know about YET.

It could very well be that they can do 25 flights instead of 10. Or it
may be just 5. It could very well be that a major inspection can extend
the life of stage by X more flights, but still remains to be seen if
that major inspection is economically sound or if building a new one
ends up cheaper.

Building new ones may present advantages if there are continuing
improvements to the rocket being made, at which point, the older rockets
without improvements are less attractive. There are a lot of variables
in this.

> What "new stuff"? Visual inspections? Validation firings on a test
> stand? What do you expect them to do between flights?

That is the question. How do you validate a rocket for reflight to
ensure nothing untoward happened during last flight. This is what SpaceX
needs to develop. This is more about procedures than engineering.

> Possibly, but I doubt it since that's what the crushable inner core is
> supposed to do. It wasn't unexpected at all.

If a leg "collapsed" because of hard landing, it still means it was a
hard landing. If the collapsible core was fully compressed, it means
additional un-absorbed G forces would have been transmitted to the
stage. Just just stating that because the gear absorbed some of the
excess G force doesn't mean that it absorbed all of it.

> Certainly, but if there had been a significant problem during that main
> burn, there would not have been enough fuel left for a landing in the
> first place.

Not talking about significant problem. Talking about some minor problem
that might have been significant. Consider Challenger. Imagine a
scenario where video showed SRB exhaust coming out of a o-ring but
directed away from ET. The flight might have gone on normally, but video
would have shown a problem that needs correcting.

You can have a jetliner taking off normally, but plume of smoke when
engine starts indicates that the engine should get a check.

> Again, possibly. But, pressurized tanks, which make up most of the
> structure of the stage, are really freaking strong.

How pressurized are they at landing ?

> As long as they
> don't rupture, the stage as a whole is very likely o.k. I'm sure SpaceX
> has done analysis and possibly even ground testing for this case

Yes. And they may be confident that the rocket can do X flights. The
issue here is problems that you have not foreseen.

> Somehow, the launch vehicle guys in both the US and U.S.S.R. got a free
> pass to ignore all of that experience with rocket engines and flight
> vehicles and clung to the mistaken belief that launch vehicles must be
> expendable simply because they started their engineering work with
> missiles instead of aircraft. Madness. Simply madness.

In a race to space, you focus to get there first, no matter how much it
costs. You don't have time to develop a landing system. And did
computers and sensors of the 1960s have the power to do a controlled
landing of a rocket ?

Also, in the USA, I somehow suspect that rocket manufacturers lobbied
government hard on the fact that re-using rockets wasn't safe.

As long as US manufacturers had no competition, there was little
incentive to add re-usability to a rocket.

When Soyuz became available commercially and started to compete in the
launch market with lower prices, the US rocket makers didn't really
react, and this left a big spot for SpaceX to come in. And one way to
compete against Soyuz is to look are re-using first stage.

Out of curiosity:
does Falcon9 have simular ratio of delta-V given by first vs second
stage compared to other non-reusable rockets ?

Say I have a rockets whose first stage goes much much further and
provides much greater delta-V, its re-entry would be more problematic
than the Falcon 9.

[JF Mezei]

On 2016-06-21 06:21, Jeff Findley wrote:

> Yes, they'll find problems and fix them. That's a given. But to
> timidly assume that vehicles are bad just because they've flown to space
> and back is silly, especially since they've been designed from the
> beginning to do just that.
>
> Somehow we've lost our "guts".

When you look at history of jetliners, it used to be like that. In fact,
the Comet flew for a while before it was discovered there was a huge
flaw in its design (square windows) that led to structural failure and
loss of life.

The Aloha airlines "convertible" accident happened decades after the 737
first flew and was certified with the tests from those days. Yet, it was
found that there were limits to the aircraft and beyond a certain numebr
of cycles, it needed its rivets closely inspected.


With every accident, we learn and more precautions are taken to prevent it.

So the "lost our guts" is merely "we're better at testing before putting
stuff in production". Today, far more tests are done to a new aircraft
before it is given its certification and allowed to fly commercially.
That is to incorporate all the knowledge learned from previous crashes
to help prevent them.

The Airbus A320 was given its certificate because it passed the
"analogue" tests of the 1980s. But after that, the agencies including
FAA realised those tests weren't enough to validate a plane's computer
software. So more tests put in.

And by the time a plane makes its first test flight, it has been
simulated to far greater extent than ever before, especially for its
software. The engines have been tested far more than ever before. So
yeah, while test pilots still wear parachutes on first few flights, it s
a remnant of days where the first flight was truly dangerous.


Back to SpaceX. When you have a hundred million payload on your head,
(and insurance companies on your back), you want to make really sure
that your procedures to qualify a stage for reflight are complete and
will detect any/all problems.

Remember the Comet. it took many flights before pressure cycles caused
cracks at the window corners to stary to spread. They didn't think of
looking for this so it wasn't detected until the crash.

[JF Mezei]

On 2016-06-21 09:34, Fred J. McCall wrote:

> Have you ever worked for Boeing or Airbus? Are you aware that rockets
> are HAND BUILT, so increasing production requires acquiring new
> workforce and bringing them up to adequate skill levels?

There is a lot of machinery involved to make the components, and I
strongly suspect that to get to the precision needed, they use CAD/CAM
driven machines to make the parts. If you increase production, you need
to invest in machinery and space to put it and the new employees.

I don't know that SpaceX right now is betting its life on ability to
re-use. Definitely betting beers on it, but not its life.

Also, in french, there is a saying "you can't sell the bear's skin
before you killed it".

SpaceX can't sell a flight on a specific reflown stage until that stage
has landed safely and passed the tests. What if you sell "the next
reusable stage1" for a launch in November, but by November, you don't
have a resusable stage1 handy ?

A solution is to keep enough recovered stage1 in stock so that you can
sell a stage1 today for launch next year, while another recocvered
stage1 sold a year ago launches next week.

This inventory may be reduced over the years as certaintly of
recoverability increases and SpaceX is abloe to more closer to "just in
time".

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-21 06:09, Jeff Findley wrote:
>
>> It should. There is nothing fundamental about a liquid fueled rocket
>> stage from an orbital launch vehicle that prevents reuse. It's just
>> that no one has *tried* all that hard to reuse one, until now.
>
>And there is nothing fundamental about jet engines to prevent reuse. And
>this is done every day by jetliners.
>

Well, DOH!

>
>HOWEVER, the airlines and FAA learned via experience that jet engines
>can only run so many hours before needing certain level of inspection,
>and after another set of hours, require a heavy maintenance check.
>

No, they didn't learn that 'from experience'. They learned it from
what the engines and vehicles were designed to be able to do. Just
like SpaceX has 'learned' that they can relaunch at least 10 times.

>
>Oh, and after a "hard" landing, the aircraft needs a maintenance check.
>

Just the landing gear and only if the landing is so 'hard' that it
exceeds the design specs of the aircraft.

>
>So SpaceX will learn via experience how many times a stage can be
>reflown with just a flashlight inpection, how hard a landing the stage
>can take without needing more serious inspection and after how many
>flights is a major inspection required (and whether such major
>maintenance is economic or not).
>

No, they will CHECK via actual experience whether or not their design
goals are holding up. Engineering ain't wishful magic, Mr Mezei.

>
>When you look at the Orbital ATK fireworks at Wallops, didn't they run
>the engines to test them before ? All seemed fine and yet, engines failed.
>

What does that have to do with the price of tea in China?

>
>Doing a flight test (including landing) of engines 10 times is cool. But
>you really need to test until they fail.
>

No you don't.

>
>There is a big difference if
>they fail on the 11th simulation vs on the 25th simulation.
>

Are you talking testing or simulation? They're not the same thing.

>
>(on the
>25th, it means that when you fly the 10th flight, the engines are still
>far from failure).
>

Maybe. Maybe not.

>
>> fired on the test stand to test and qualify them. There is no
>> fundamental problem here that needs solving.
>
>It is a question of validating the predictions. They've weeded out the
>problems they know about. They haven't weeded out problems they don't
>know about YET.
>

And may never know about them and thus never weed them out.

>
>It could very well be that they can do 25 flights instead of 10. Or it
>may be just 5. It could very well be that a major inspection can extend
>the life of stage by X more flights, but still remains to be seen if
>that major inspection is economically sound or if building a new one
>ends up cheaper.
>

And maybe unicorns will fart magic rainbow dust all over everything.
Do you know ANYTHING about how actual engineering works?

>
>Building new ones may present advantages if there are continuing
>improvements to the rocket being made, at which point, the older rockets
>without improvements are less attractive. There are a lot of variables
>in this.
>

If you're constantly making hardware changes, every flight is a new
experiment. This is what SpaceX is trying to AVOID with things like
standard engine designs.

>
>>
>> What "new stuff"? Visual inspections? Validation firings on a test
>> stand? What do you expect them to do between flights?
>
>That is the question. How do you validate a rocket for reflight to
>ensure nothing untoward happened during last flight. This is what SpaceX
>needs to develop. This is more about procedures than engineering.
>

I'm sorry. I was apparently unclear. YOU 'VALIDATE' THEM THE SAME
WAY YOU VALIDATE A NEW ONE. They already have that. All clear now?

>
>> Possibly, but I doubt it since that's what the crushable inner core is
>> supposed to do. It wasn't unexpected at all.
>
>If a leg "collapsed" because of hard landing, it still means it was a
>hard landing.
>

The leg didn't 'collapse'. It did just what it was supposed to do.
The 'crush core' crushed. That's what it's there for. You obviously
either never understood this when it was explained to you in detail or
you have the long term memory of a fucking mayfly.

>
>If the collapsible core was fully compressed, it means
>additional un-absorbed G forces would have been transmitted to the
>stage.
>

Wrong.

>
>Just just stating that because the gear absorbed some of the
>excess G force doesn't mean that it absorbed all of it.
>

If it didn't the leg would have broken. It didn't. The leg and crush
core performed just like they were supposed to.

Pay attention when people explain these things to you.

Read what SpaceX says.

<remaining ignorance elided>

Buy a fucking clue. Then phone a friend, if you have one, to explain
to you just what a 'clue' is and why they're useful.

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> JF Mezei <jfmezei...@vaxination.ca> wrote:
>
>>On 2016-06-21 06:09, Jeff Findley wrote:
>>
>>> It should. There is nothing fundamental about a liquid fueled rocket
>>> stage from an orbital launch vehicle that prevents reuse. It's just
>>> that no one has *tried* all that hard to reuse one, until now.
>>
>>And there is nothing fundamental about jet engines to prevent reuse. And
>>this is done every day by jetliners.
>>
>
> Well, DOH!
>
>>
>>HOWEVER, the airlines and FAA learned via experience that jet engines
>>can only run so many hours before needing certain level of inspection,
>>and after another set of hours, require a heavy maintenance check.
>>
>
> No, they didn't learn that 'from experience'. They learned it from
> what the engines and vehicles were designed to be able to do.

Nonsense.

Early jet engines had a service life (Time Between Overhaul or TBO) of
10-15 hours.

It took decades of refinements to get TBO up to the current 10's of
thousands of hours, with inspection times and many parts replaced much
more often then that, and those times are STILL determined by operational
and maintenance records.

New engine designes usually have short maintenance and inspection
time requirements until the engine has proved itself in use.


--
Jim Pennino

[Sergio]

the problem is vertical landing, all that fuel to slow you down, you
have to take round trip. better to land it like the shuttle, glide
down, no fuel needed.

OBW, military has done the vertical landing R+D for a while, but it took
the microprocesser age to get it smart enough

[ji...@specsol.spam.sux.com]

Gliding down requires an aerodynamic configuration, i.e. wings and
control surfaces as well as retractable landing gear, which is a lot
of extra weight and complexity.

> OBW, military has done the vertical landing R+D for a while, but it took
> the microprocesser age to get it smart enough

So you need a microprocessor, a simple altitude radar, and throttles on
the engines, BFD.



--
Jim Pennino

[Jeff Findley]

In article <pdOdnWenpsr7pvTK...@earthlink.com>,
moo...@deletethisgreenms.com says...

>
> "Jeff Findley" wrote in message
> news:MPG.31d2dc7ea...@news.eternal-september.org...
> >
> >Advocates of reusable launch vehicle tech have known this since the days
> >of the X-15 (earlier if you want to count the German rocket powered
> >fighter experience). It was rocket powered and the three copies which
> >were built flew so many times, I can never remember exactly how many
> >flights were made.
>
> 199. I always remember that because they were 1 short of 200 and did try for

> it, but couldn?t get the conditions and everything in order before the money

> finally ran out.
>
> Jenkins (no surprise) has a good book on the X-15.

So 199 flights out of 3 airframes and the only thing really holding them
back from flying more was funding. Follow-on vehicles were thought
about as well (like a delta-winged X-15), but never got a chance to fly.
And everyone should remember, the first X-15 flight was 1959 and last
flight was 1968. So this entire program was based on 1950s technology
with some updates in the 1960s.

[Jeff Findley]

In article <nkbn02$76d$1...@news.hpeswlab.net>, rick....@hpe.com says...

>
> In sci.space.policy Jeff Findley <jfin...@cinci.nospam.rr.com> wrote:
> > They've done extensive tests of the Merlin engines, which should be
> > the "long pole in the tent" when it comes to reflights without
> > refurbishment.
>
> Would the next pole be the welds in the plumbing, followed by
> structure?

Depends if there are defects (design or manufacturing) which develop
which need to be corrected.

The engines are arguably the long pole because the expendable camp keeps
saying you simply can't make a LOX/kerosene engine that isn't
susceptible to coking of the kerosene in the engine. If SpaceX solved
this issue, it's certainly some "secret sauce" they won't want to talk
about openly (trade secret).

[JF Mezei]

On 2016-06-21 15:47, Fred J. McCall wrote:

> If you're constantly making hardware changes, every flight is a new
> experiment. This is what SpaceX is trying to AVOID with things like
> standard engine designs.

An aircraft gets constant improvements over the years, same with its
engines. It's called fine tuning. And common to aerospace.

That is why for insance, when they discovered flaws on some A380 Roll
Royce engines they applied to a narrow set of aircraft as that flaw had
been fixed for engines built after X date.

If Musk isn't tweaking his designs to increase efficiency of engines or
lighten the stages, I am quite surprised. This doesn't mean redrawing
the whole thing.

> The leg didn't 'collapse'. It did just what it was supposed to do.

The crush core is a failsafe backup. It isn't meant to crush to absorb
landing on a normal landing. So this means that landing was harder than
nominal.


Unless you have access to the engineering data from the landing, you
cannot state that the crush zone absorbed enough of the G force that
what was left was not a problem for the stage to absorb without damage.

Yes, the crush zone worked as designed. But if it is designed to absorb
X G force, and you have a impact greater than X, the crush zone still
works as designed, expect that everything above X gets transmitted to
the stage.

[Greg (Strider) Moore]

"Jeff Findley" wrote in message

news:MPG.31d388574...@news.eternal-september.org...

>
>In article <pdOdnWenpsr7pvTK...@earthlink.com>,
>moo...@deletethisgreenms.com says...
>>
>> "Jeff Findley" wrote in message
>> news:MPG.31d2dc7ea...@news.eternal-september.org...
>> >
>> >Advocates of reusable launch vehicle tech have known this since the days
>> >of the X-15 (earlier if you want to count the German rocket powered
>> >fighter experience). It was rocket powered and the three copies which
>> >were built flew so many times, I can never remember exactly how many
>> >flights were made.
>>
>> 199. I always remember that because they were 1 short of 200 and did try
>> for
>> it, but couldn?t get the conditions and everything in order before the
>> money
>> finally ran out.
>>
>> Jenkins (no surprise) has a good book on the X-15.
>
>So 199 flights out of 3 airframes and the only thing really holding them
>back from flying more was funding. Follow-on vehicles were thought
>about as well (like a delta-winged X-15), but never got a chance to fly.
>And everyone should remember, the first X-15 flight was 1959 and last
>flight was 1968. So this entire program was based on 1950s technology
>with some updates in the 1960s.

And keep in mind they basically had a vehicle loss that resulted in a
rebuilt vehicle and the complete loss of an airframe.
(56-6671 was rebuilt X-15A-2, 56-6672, X-15-3 was a complete vehicle loss)

The X-15 program is often considered one of the most successful and
productive X programs to date.

And of course don't forget the unknown flight by noted test pilot Mike Mars.
:-)

[ji...@specsol.spam.sux.com]

In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
> On 2016-06-21 15:47, Fred J. McCall wrote:
>
>> If you're constantly making hardware changes, every flight is a new
>> experiment. This is what SpaceX is trying to AVOID with things like
>> standard engine designs.
>
> An aircraft gets constant improvements over the years, same with its
> engines. It's called fine tuning.

Nope, with aircraft it is a new model, e.g. the 747 has over twenty
models and the 777 has 7 and each model has to be certified.

https://en.wikipedia.org/wiki/Boeing_747
https://en.wikipedia.org/wiki/Boeing_777


--
Jim Pennino

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-21 09:34, Fred J. McCall wrote:
>>
>> Have you ever worked for Boeing or Airbus? Are you aware that rockets
>> are HAND BUILT, so increasing production requires acquiring new
>> workforce and bringing them up to adequate skill levels?
>>
>
>There is a lot of machinery involved to make the components, and I
>strongly suspect that to get to the precision needed, they use CAD/CAM
>driven machines to make the parts.
>

Since those are used for pretty much everything, that goes without
saying. It also goes without saying that nobody makes all their own
parts these days.

>
>If you increase production, you need
>to invest in machinery and space to put it and the new employees.
>

Well, DOH! Aren't you just Captain Obvious?

>
>I don't know that SpaceX right now is betting its life on ability to
>re-use. Definitely betting beers on it, but not its life.
>

You don't know much of anything, but that doesn't surprise anyone
anymore.

>
>Also, in french, there is a saying "you can't sell the bear's skin
>before you killed it".
>

The French say many stupid and inappropriate non sequiturs.

>
>SpaceX can't sell a flight on a specific reflown stage until that stage
>has landed safely and passed the tests. What if you sell "the next
>reusable stage1" for a launch in November, but by November, you don't
>have a resusable stage1 handy ?
>

Well duh, Captain Obvious.

>
>A solution is to keep enough recovered stage1 in stock so that you can
>sell a stage1 today for launch next year, while another recocvered
>stage1 sold a year ago launches next week.
>

That's certainly *A* solution, but it's not the one anyone with sense
would choose.

>
>This inventory may be reduced over the years as certaintly of
>recoverability increases and SpaceX is abloe to more closer to "just in
>time".
>

That inventory may be reduced to zero at any time.

[Vaughn Simon]

Not so. There are several processes by which in-service aircraft are
routinely upgraded and modified. The basic method is by STC. "A
supplemental type certificate ( STC ) is a type certificate ( TC )
issued when an applicant has received FAA approval to modify an
aeronautical product from its original design."

STCs are available for upgrades and aircraft modifications both very
simple, and amazingly major. Sometimes brand new aircraft are built
that incorporate a pile of various STCs.

Another way is when the FAA orders a change for safety reasons. This is
called an Airworthiness Directive (AD)

Another way is that individual aircraft or engine parts may be improved
is via a Parts Manufacturer Approval (PMA). "a combined design and
production approval for modification and replacement articles. It allows
a manufacturer to produce and sell these..."
There is a healthy market for improved parts in the aviation industry.
If you can figure out how to make something better or to solve a
recurring problem, there is money to be made.

[ji...@specsol.spam.sux.com]

In sci.physics Vaughn Simon <vaugh...@gmail.com> wrote:
> On 6/22/2016 1:01 AM, ji...@specsol.spam.sux.com wrote:
>> In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>> On 2016-06-21 15:47, Fred J. McCall wrote:
>>>
>>>> If you're constantly making hardware changes, every flight is a new
>>>> experiment. This is what SpaceX is trying to AVOID with things like
>>>> standard engine designs.
>>>
>>> An aircraft gets constant improvements over the years, same with its
>>> engines. It's called fine tuning.
>>
>> Nope, with aircraft it is a new model, e.g. the 747 has over twenty
>> models and the 777 has 7 and each model has to be certified.
>>
>> https://en.wikipedia.org/wiki/Boeing_747
>> https://en.wikipedia.org/wiki/Boeing_777
>>
>>
> Not so. There are several processes by which in-service aircraft are
> routinely upgraded and modified. The basic method is by STC. "A
> supplemental type certificate ( STC ) is a type certificate ( TC )
> issued when an applicant has received FAA approval to modify an
> aeronautical product from its original design."
>
> STCs are available for upgrades and aircraft modifications both very
> simple, and amazingly major. Sometimes brand new aircraft are built
> that incorporate a pile of various STCs.

STCs do not make major changes in the airframe and each has to be certified.

My airplane has several STCs; a split nose cowl instead of one piece,
ground adjustable cowl flap, modern rudder light, varnier mixture
control. None significantly changes anything.

An engine design STC requires a LOT of certification effort.

> Another way is when the FAA orders a change for safety reasons. This is
> called an Airworthiness Directive (AD)

Which is generally to address something that is wrong, such as adding
reinforcement to a wing spar that tends to crack or frequent inspection
of things found to have limited life or high wear.

> Another way is that individual aircraft or engine parts may be improved
> is via a Parts Manufacturer Approval (PMA). "a combined design and
> production approval for modification and replacement articles. It allows
> a manufacturer to produce and sell these..."
> There is a healthy market for improved parts in the aviation industry.
> If you can figure out how to make something better or to solve a
> recurring problem, there is money to be made.

PMA parts are not "better" parts, they are replacement parts that are
at least as good as the original part that are not made by the original
manufacture.



--
Jim Pennino

[Vaughn Simon]

On 6/22/2016 2:25 PM, ji...@specsol.spam.sux.com wrote:
> In sci.physics Vaughn Simon <vaugh...@gmail.com> wrote:
>> On 6/22/2016 1:01 AM, ji...@specsol.spam.sux.com wrote:

>> STCs are available for upgrades and aircraft modifications both very
>> simple, and amazingly major. Sometimes brand new aircraft are built
>> that incorporate a pile of various STCs.
>
> STCs do not make major changes in the airframe

STCs make both small and major changes. For example, you can take an
old DC-3 airliner and make a vastly different plane from it by swapping
out the ancient radial engines for turboprops, stretch the fuselage and
also perhaps add a big cargo door. The result is called a BT-67, bit
the resulting aircraft is still type-certified as a DC-3 and it's all
done by the STC process (STC SA4840NM)
http://www.baslerturbo.com/overview1.html

You could call the above example "Minor modifications" if you wish, but
you would be far out on a limb.

> and each has to be certified.

Yes! That's why the last word in "Supplemental Type Certificate" (STC)
is "Certificate".

> My airplane has several STCs; a split nose cowl instead of one piece,
> ground adjustable cowl flap, modern rudder light, varnier mixture
> control. None significantly changes anything.
>
> An engine design STC requires a LOT of certification effort.

Arm waving

>
>> Another way is when the FAA orders a change for safety reasons. This is
>> called an Airworthiness Directive (AD)
>
> Which is generally to address something that is wrong, such as adding
> reinforcement to a wing spar that tends to crack or frequent inspection
> of things found to have limited life or high wear.

Which is exactly what I imply above. It is still a modification to a
type certified aircraft and the aircraft model number is still the same
after it is done. Your point?

>
>> Another way is that individual aircraft or engine parts may be improved
>> is via a Parts Manufacturer Approval (PMA). "a combined design and
>> production approval for modification and replacement articles. It allows
>> a manufacturer to produce and sell these..."
>> There is a healthy market for improved parts in the aviation industry.
>> If you can figure out how to make something better or to solve a
>> recurring problem, there is money to be made.
>
> PMA parts are not "better" parts, they are replacement parts that are
> at least as good as the original part that are not made by the original
> manufacture.
>

Oh yes they can be! You can buy a PMA starter for your airplane that
is lighter and more powerful than the original. There are a multitude
of internal engine parts that are improvements over the originals. (Or
at least, claimed to be better.)

And I might also point out that most GA aircraft these days very likely
incorporate electronics that wasn't even invented when their aircraft
model was originally type-certified.

Anyhow, if you wish to continue arm waving and hair-splitting on this
topic,
you are on your own. This thread is about the Falcon 9.

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>> JF Mezei <jfmezei...@vaxination.ca> wrote:
>>
>>>On 2016-06-21 06:09, Jeff Findley wrote:
>>>
>>>> It should. There is nothing fundamental about a liquid fueled rocket
>>>> stage from an orbital launch vehicle that prevents reuse. It's just
>>>> that no one has *tried* all that hard to reuse one, until now.
>>>
>>>And there is nothing fundamental about jet engines to prevent reuse. And
>>>this is done every day by jetliners.
>>>
>>
>> Well, DOH!
>>
>>>
>>>HOWEVER, the airlines and FAA learned via experience that jet engines
>>>can only run so many hours before needing certain level of inspection,
>>>and after another set of hours, require a heavy maintenance check.
>>>
>>
>> No, they didn't learn that 'from experience'. They learned it from
>> what the engines and vehicles were designed to be able to do.
>>
>
>Nonsense.
>

Nonsense your ass, Chimp.

>
>Early jet engines had a service life (Time Between Overhaul or TBO) of
>10-15 hours.
>

Yes, they did, because of things like limits on metallurgy. That was
the design service life and they knew it going in. They didn't just
build the things and then say, "Now we'll just fly the fuckers and see
what happens".

>
>It took decades of refinements to get TBO up to the current 10's of
>thousands of hours, with inspection times and many parts replaced much
>more often then that, and those times are STILL determined by operational
>and maintenance records.
>

Yes, it did, but that's because basic materials science improved, not
because of increased experience with the old short-lived systems. What
YOU are talking about is not what Moron Mezei is talking about.

>
>New engine designes usually have short maintenance and inspection
>time requirements until the engine has proved itself in use.
>

Cite?

[Fred J. McCall]

The wings to do that weigh more than the fuel required. They also
cost more. They also take away the option of using all the fuel and
expending the stage, because that gets you nothing as you're still
hauling around all that extra structure.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-21 15:47, Fred J. McCall wrote:
>>
>> If you're constantly making hardware changes, every flight is a new
>> experiment. This is what SpaceX is trying to AVOID with things like
>> standard engine designs.
>>
>
>An aircraft gets constant improvements over the years, same with its
>engines. It's called fine tuning. And common to aerospace.
>

How many years experience in the aerospace industry to you have?

>
>That is why for insance, when they discovered flaws on some A380 Roll
>Royce engines they applied to a narrow set of aircraft as that flaw had
>been fixed for engines built after X date.
>

That 'narrow set of aircraft' being "all aircraft prior to the fix
being incorporated into engine production".

>
>If Musk isn't tweaking his designs to increase efficiency of engines or
>lighten the stages, I am quite surprised. This doesn't mean redrawing
>the whole thing.
>

Of course it does. When you change shit like that the guidance laws
of the vehicle change which means you rewrite big pieces of software
and you're back at square one as far as knowing anything.

>
>> The leg didn't 'collapse'. It did just what it was supposed to do.
>
>The crush core is a failsafe backup.
>

Wrong. Go look up 'failsafe'.

>
>It isn't meant to crush to absorb
>landing on a normal landing. So this means that landing was harder than
>nominal.
>

Captain Obvious strikes again.

>
>Unless you have access to the engineering data from the landing, you
>cannot state that the crush zone absorbed enough of the G force that
>what was left was not a problem for the stage to absorb without damage.
>

Of course I can, because I can read and remember what Elon Musk said
about this while you apparently are incapable of that feat. 'The
stage' doesn't absorb shit. The leg breaks, the stage topples over,
and you write it off.

>
>Yes, the crush zone worked as designed. But if it is designed to absorb
>X G force, and you have a impact greater than X, the crush zone still
>works as designed, expect that everything above X gets transmitted to
>the stage.
>

We're not talking about "G force". I know you keep trying to use
fancy terms that you don't know the meaning of so that you sound
erudite, but it just makes you sound stupid.

It doesn't get 'transmitted to the stage'. The fucking leg breaks,
idiot.

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>> JF Mezei <jfmezei...@vaxination.ca> wrote:
>>>
>>>>On 2016-06-21 06:09, Jeff Findley wrote:
>>>>
>>>>> It should. There is nothing fundamental about a liquid fueled rocket
>>>>> stage from an orbital launch vehicle that prevents reuse. It's just
>>>>> that no one has *tried* all that hard to reuse one, until now.
>>>>
>>>>And there is nothing fundamental about jet engines to prevent reuse. And
>>>>this is done every day by jetliners.
>>>>
>>>
>>> Well, DOH!
>>>
>>>>
>>>>HOWEVER, the airlines and FAA learned via experience that jet engines
>>>>can only run so many hours before needing certain level of inspection,
>>>>and after another set of hours, require a heavy maintenance check.
>>>>
>>>
>>> No, they didn't learn that 'from experience'. They learned it from
>>> what the engines and vehicles were designed to be able to do.
>>>
>>
>>Nonsense.
>>
>
> Nonsense your ass, Chimp.
>
>>
>>Early jet engines had a service life (Time Between Overhaul or TBO) of
>>10-15 hours.
>>
>
> Yes, they did, because of things like limits on metallurgy. That was
> the design service life and they knew it going in.

No, they didn't; in the early days no one had any clue how long things
would hang together in an entirely new application. You learn service
life from experience.

> They didn't just
> build the things and then say, "Now we'll just fly the fuckers and see
> what happens".

That is EXACTLY what they did in the early days.

>>It took decades of refinements to get TBO up to the current 10's of
>>thousands of hours, with inspection times and many parts replaced much
>>more often then that, and those times are STILL determined by operational
>>and maintenance records.
>>
>
> Yes, it did, but that's because basic materials science improved, not
> because of increased experience with the old short-lived systems.

It was a mix of both.

>>New engine designes usually have short maintenance and inspection
>>time requirements until the engine has proved itself in use.
>>
>
> Cite?

Any new aircraft engine brought to market in modern times; two specific
examples are Rotax and Thielert.


--
Jim Pennino

[Fred J. McCall]

Bullshit.

>> They didn't just
>> build the things and then say, "Now we'll just fly the fuckers and see
>> what happens".
>
>That is EXACTLY what they did in the early days.
>

Nonsense.

>>>It took decades of refinements to get TBO up to the current 10's of
>>>thousands of hours, with inspection times and many parts replaced much
>>>more often then that, and those times are STILL determined by operational
>>>and maintenance records.
>>>
>>
>> Yes, it did, but that's because basic materials science improved, not
>> because of increased experience with the old short-lived systems.
>
>It was a mix of both.
>

Nonsense.

>>>New engine designes usually have short maintenance and inspection
>>>time requirements until the engine has proved itself in use.
>>>
>>
>> Cite?
>
>Any new aircraft engine brought to market in modern times; two specific
>examples are Rotax and Thielert.
>

So let's summarize and I think you'll find you're telling me
"nonsense" while you're agreeing with me.

I claim that something is DESIGNED for a specific minimum performance.
If that was not true, you would have to tear every airplane down after
every flight, which we obviously do not do.

Mezei claims that you cannot know that you will meet that minimum
performance unless you tear every airplane apart after every flight
and fly them to destruction.

YOU claim that you get "short maintenance and inspection time
requirements" (that 'minimum performance' I'm talking about) and that
then you do "maintenance and inspection" and that those times MIGHT
lengthen with experience.

In other words, you claimed I was speaking "nonsense" while you were
agreeing with me. That just makes you an unthinking asshole, Chimp.


--
You are
What you do
When it counts.

[JF Mezei]

On 2016-06-22 14:25, ji...@specsol.spam.sux.com wrote:

> STCs do not make major changes in the airframe and each has to be certified.

But there are many changes done which do not change the aircraft's
behaviour/performance but lighten its weight. Those are rollned into
the production line over the years. So a 737-800 built today is not
exactly the same as the first 737-800 that rolled off the production line.

The first bunch of 777-200 produced in 1995 had limited range due to
them being overweight. But within a year, Boeing reduced the weight of
aircraft and have the 777-200 with increased gross weight which enabled
the 777-200 to do trans atlantic with decent load.

Of course, Boeing also produce variants sur as the ER and LR versions
and those get certified.

If you replace component A with component B, and B has been tested to
perform the same as A despite being lighter, you don't need to recertify
the aircraft.

It would be silly of SpaceX not to integrate improvements to the
production line as they see opportunities to improve things. For one
thing, althopugh McCall states they doN't change anything, it is pretty
obvious that they are constntly fine tuning the landing software.

Also, consider when they loaded the rocket with cooled fuel to increase
performance. I suspect there was software adaptation to this as well.

[JF Mezei]

On 2016-06-22 15:23, Fred J. McCall wrote:

> Yes, they did, because of things like limits on metallurgy. That was
> the design service life and they knew it going in. They didn't just
> build the things and then say, "Now we'll just fly the fuckers and see
> what happens".

Exactly what they did with the Comet. They had not considered the issue
of pressurization cycles on airframe and stress it causes on square
corners of windows. It took a while for the problem to manifest itself
and when it did, people died.

This is why to this day, you don't see square windows on aircraft that
are pressurized. And this is why today, aircraft airframe
maintenance/inspection is dicated not just by hours of flight but also
pressurization cycles. (similar issue with the Aloha convertible 737).

You really learn about a system's limits when it goes beyond its limits.

Those GTO flights are testing Falcon9's limits on succesful landings.
And with every flight, I am pressure sure they tweak the software and
possibly hardware to increase the odds of a succesful return.

To state that Flacon 9 is in production and doesn't change is silly.

> Yes, it did, but that's because basic materials science improved, not
> because of increased experience with the old short-lived systems.

When you travel into new territory, you cannot predict every problem.
The Comet is a good example of not thinking about a problem, it wasn't
about materials improving.

Apollo 1 is another example where they didn't consider the danger of
pressurizing a module to 16.7 PSI of pure Oxygen.

>What
> YOU are talking about is not what Moron Mezei is talking about.

Your level of professionalisn is very high.

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:

<snip>

> I claim that something is DESIGNED for a specific minimum performance.

Of course it is and based on the knowledge one has at the time.

> If that was not true, you would have to tear every airplane down after
> every flight, which we obviously do not do.

Nope.

You test fly the design looking for design discrepancies and errors.

After the design is verified, it goes into production and the required
periodic inspections may or may not find subtle design flaws such as
a gusset that is under strength and needs to be beefed up.

> Mezei claims that you cannot know that you will meet that minimum
> performance unless you tear every airplane apart after every flight
> and fly them to destruction.

I don't care what Mezei claims.

> YOU claim that you get "short maintenance and inspection time
> requirements" (that 'minimum performance' I'm talking about) and that
> then you do "maintenance and inspection" and that those times MIGHT
> lengthen with experience.

Nope; the comment was specifically about engines and things like engine
part replacement times and engine overhaul times. This is called "service
life", not performance.

> In other words, you claimed I was speaking "nonsense" while you were
> agreeing with me. That just makes you an unthinking asshole, Chimp.

I see you are STILL an argumentative, self centered ass.


--
Jim Pennino

[JF Mezei]

On 2016-06-22 17:37, Fred J. McCall wrote:

> Mezei claims that you cannot know that you will meet that minimum
> performance unless you tear every airplane apart after every flight
> and fly them to destruction.

Don't attribute your fantasies to me. I didn't claim that.


When you have a new product, you don't have any evidence of reliability.
You have to build this over time. And in order to determine how many
times a rocket can fly, you have to do frequent inspections to detect if
the last flight caused any degradation.

You may have designed a rocket to fly 10 times, but the proof is in the
pudding.

You can't say Falcon is able to be reflown 10 times until sufficient
number of stage 1s have been reflown 10 times to validate the design.

New airplanes are designed to be reliable and fly on single engine if
needed. But they don't get ETOPS certification until they have flown a
certain number of hours to prove engine reliability statistics. (and
initial ETPOS is extended over time as reliability has further proven.


When the A380 was first flown commercially (SIN to SYD), Airbus and
Rolls Royce had teams at both airports to inspect aircraft after every
flight, and systems to notify them of problems during a flight so they
could fix things quickly as soon as airplane landed.

Despite all the testing during certification, they knew that glitches
were bound to show up during comemercial operations with the aircraft
flying close to 20 hours per day.

This isn't just for design problems, but also potential production
glitches where an aircraft may not have had a perfect assembly, or some
component was deffective etc.


Consider the possibility that slight variations during production of
Falcom 9s might result in some being able to be reflown 5 times before
obvious signs of wear appear, while others could go 10 or 15 times
before same signs happen.

Only proper testing/inspection after each flight will give you that
information. And IF you find diferrences, you can then trace back to
manufacturing to find out what was done differently and fix that.

The days of carelessly sending stuff up are over. SpaceX is a business
and gets paid to deliver very expensive cargo to orbit. It isn't some
cowboy astronaut. As such they are more likelty to be very vigilent
with rocket re-use to validate that the plan is working isntead of
carelessly relaunching them just because the plan was to relainch them.

[ji...@specsol.spam.sux.com]

In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:

Most of this is apples and oranges as Spacex is not producing certified
aircraft.



--
Jim Pennino

[JF Mezei]

On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:

> Most of this is apples and oranges as Spacex is not producing certified
> aircraft.

McCall had argued SpaceX can't change its design because it is in
production.

[Jeff Findley]

In article <teplmb1t4q98ap8a1...@4ax.com>,
fjmc...@gmail.com says...

> >the problem is vertical landing, all that fuel to slow you down, you
> >have to take round trip. better to land it like the shuttle, glide
> >down, no fuel needed.
> >
>
> The wings to do that weigh more than the fuel required. They also
> cost more. They also take away the option of using all the fuel and
> expending the stage, because that gets you nothing as you're still
> hauling around all that extra structure.
>

Agreed. This is key if there is a problem with an engine and it has to
be shut down during the mission. With Falcon 9R, you burn the fuel
which would have been used for turn-around, reentry, and landing and
instead use it to make up for the performance shortfall. Yes, it turns
the reusable into an expendable, but the primary mission succeeds and
places the customer's payload in the desired orbit.

You simply can't do that with a winged return vehicle unless you also
keep a fuel reserve on board. If you go that route, you have paid a
double mass penalty for recovery (once for wings and a second time for a
fuel reserve).

[JF Mezei]

On 2016-06-22 21:57, Jeff Findley wrote:

> instead use it to make up for the performance shortfall. Yes, it turns
> the reusable into an expendable, but the primary mission succeeds and
> places the customer's payload in the desired orbit.

Not a problem now, but should launch business become highly competitive
and forces SpaceX to price launches based on assumption of recovering
stage, then events where the stage is not recovered may generate red ink
in the financial statements.

> You simply can't do that with a winged return vehicle unless you also
> keep a fuel reserve on board.

Say the Falcon9 were in the shape of the Concorde with wings having mass
of just 1kg. (aka: mythical no weight penalty).

After main engine cutoff and stage2 separation, if you leave the stage1
to coast, how far would it go before it lands ?

Eastern Atlantic ? Europe ? Russia/Middle East ? Asia/Australia ?
Pacific ? California ?

Now, if we forget the wings:

What if stage1 accelerated a bit and made it to the Coast of California
and landed in Hawthorne ? Would that cost more fuel than fuel needed to
put on the brakes and accelerate westwards back to KSC/barge ?

I understand the logistics of wanting it to land near the USA. Landing
in Middle east would require hefty transportation back to USA. But if
you went around the world once would that save fuel while giving you
logistics advantage of landing near SpaceX's California facility ?

> If you go that route, you have paid a
> double mass penalty for recovery (once for wings and a second time for a
> fuel reserve).

Shuttle: because it was a LOX/LH2 vehicle, the wings were empty.

What if Stage1's wings become kerosene tanks just like in airliners ?
The wings would no longer be dead weight. They may end up being heavier
tank than current design, but if extra weight is less than weight of
fuel to land, it could be a net gain.

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-22 14:25, ji...@specsol.spam.sux.com wrote:
>
>> STCs do not make major changes in the airframe and each has to be certified.
>
>But there are many changes done which do not change the aircraft's
>behaviour/performance but lighten its weight.
>

And you think that such changes "do not change the aircraft's
behaviour/performance"? I'm sorry, but that's just nuts.

>
>If you replace component A with component B, and B has been tested to
>perform the same as A despite being lighter, you don't need to recertify
>the aircraft.
>

Of course you have to do something in the way of recertification.
You've changed CG, climb rates, etc.

>
>It would be silly of SpaceX not to integrate improvements to the
>production line as they see opportunities to improve things. For one
>thing, althopugh McCall states they doN't change anything,
>

Learn to read. What I've said is that the do not constantly tinker.

>
>it is pretty
>obvious that they are constntly fine tuning the landing software.
>

And why is that "pretty obvious"? Is this based on your long an
non-existent history in aerospace?

>
>Also, consider when they loaded the rocket with cooled fuel to increase
>performance. I suspect there was software adaptation to this as well.
>

Of course there was. That was a planned change, not 'tinkering'.

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>
><snip>
>
>> I claim that something is DESIGNED for a specific minimum performance.
>
>Of course it is and based on the knowledge one has at the time.
>
>> If that was not true, you would have to tear every airplane down after
>> every flight, which we obviously do not do.
>
>Nope.
>

Yep. You just agreed, above, Chimp.

>
>You test fly the design looking for design discrepancies and errors.
>
>After the design is verified, it goes into production and the required
>periodic inspections may or may not find subtle design flaws such as
>a gusset that is under strength and needs to be beefed up.
>

And those 'required periodic inspections' are based on what, Chimp?

>
>> Mezei claims that you cannot know that you will meet that minimum
>> performance unless you tear every airplane apart after every flight
>> and fly them to destruction.
>
>I don't care what Mezei claims.
>

Then why the fuck are you even in this discussion?

>> YOU claim that you get "short maintenance and inspection time
>> requirements" (that 'minimum performance' I'm talking about) and that
>> then you do "maintenance and inspection" and that those times MIGHT
>> lengthen with experience.
>
>Nope; the comment was specifically about engines and things like engine
>part replacement times and engine overhaul times. This is called "service
>life", not performance.
>

And "service life" is part of the engineering "design performance",
Chimpshit.

>> In other words, you claimed I was speaking "nonsense" while you were
>> agreeing with me. That just makes you an unthinking asshole, Chimp.
>
>I see you are STILL an argumentative, self centered ass.
>

Only when dealing with an argumentative, self centered ass.


--

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-22 15:23, Fred J. McCall wrote:
>
>> Yes, they did, because of things like limits on metallurgy. That was
>> the design service life and they knew it going in. They didn't just
>> build the things and then say, "Now we'll just fly the fuckers and see
>> what happens".
>
>Exactly what they did with the Comet.
>

Nonsense!

<snip Moron Mezei ignorance>

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-22 17:37, Fred J. McCall wrote:
>
>> Mezei claims that you cannot know that you will meet that minimum
>> performance unless you tear every airplane apart after every flight
>> and fly them to destruction.
>
>Don't attribute your fantasies to me. I didn't claim that.
>

Oh, come now. The least you can do is read and understand what YOU
say.

>
>When you have a new product, you don't have any evidence of reliability.
>

Of course you do.

<snip Moron Mezei ignorance>

You know, given a choice between what Elon Musk says and what you pull
out of your ass, I think I'm going to go with Musk.

[Jeff Findley]

In article <576b49b3$0$9153$c3e8da3$5d8f...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-22 21:57, Jeff Findley wrote:
>
> > instead use it to make up for the performance shortfall. Yes, it turns
> > the reusable into an expendable, but the primary mission succeeds and
> > places the customer's payload in the desired orbit.
>
> Not a problem now, but should launch business become highly competitive
> and forces SpaceX to price launches based on assumption of recovering
> stage, then events where the stage is not recovered may generate red ink
> in the financial statements.

Not really. The stages aren't that expensive to build, because they're
making money now and aren't counting on reuse yet. And they still have
a huge launch backlog that will take years to make up. So, losing a few
stages here and there won't hurt them one bit. On the contrary, not
underperforming on the primary mission would be *worse* for business,
since that would impact the customers directly!

Perhaps, sometime in the far distant future, this might impact them if
the competition is also reusing their stages and they get into a price
war with each other. But that is likely 5 to 10 years away, and in the
meantime, SpaceX will continue to innovate. So who knows where we'll be
then.

> > You simply can't do that with a winged return vehicle unless you also
> > keep a fuel reserve on board.
>
> Say the Falcon9 were in the shape of the Concorde with wings having mass
> of just 1kg. (aka: mythical no weight penalty).

I'm not going to engage in this sort of senseless speculation. Wings
are heavy and also impose a significant drag penalty during launch.
They are inferior to vertical landing for unmanned stage recovery as
long as you're willing to accept that you'll lose a stage from time to
time.

> > If you go that route, you have paid a
> > double mass penalty for recovery (once for wings and a second time for a
> > fuel reserve).
>
> Shuttle: because it was a LOX/LH2 vehicle, the wings were empty.
>
> What if Stage1's wings become kerosene tanks just like in airliners ?
> The wings would no longer be dead weight. They may end up being heavier
> tank than current design, but if extra weight is less than weight of
> fuel to land, it could be a net gain.

Wings are far more heavy (kg of wing mass per liter of storage volume)
than cylindrical tanks. This is basic geometry. Spheres are the most
mass efficient, but don't make for good aerodynamics, so cylinders are
the second most mass efficient, so that's what is used.

[Fred J. McCall]

Mezei can't read and has the attention span of a mayfly. I said no
such thing.


--
"You take the lies out of him, and he'll shrink to the size of
your hat; you take the malice out of him, and he'll disappear."
-- Mark Twain

[Fred J. McCall]

JF Mezei <jfmezei...@vaxination.ca> wrote:

>On 2016-06-22 21:57, Jeff Findley wrote:
>
>> instead use it to make up for the performance shortfall. Yes, it turns
>> the reusable into an expendable, but the primary mission succeeds and
>> places the customer's payload in the desired orbit.
>
>Not a problem now, but should launch business become highly competitive
>and forces SpaceX to price launches based on assumption of recovering
>stage, then events where the stage is not recovered may generate red ink
>in the financial statements.
>

SpaceX already beats everyone else on price. Only crazy people price
the way you suggest SpaceX would.

>
>> You simply can't do that with a winged return vehicle unless you also
>> keep a fuel reserve on board.
>
>Say the Falcon9 were in the shape of the Concorde with wings having mass
>of just 1kg. (aka: mythical no weight penalty).
>
>After main engine cutoff and stage2 separation, if you leave the stage1
>to coast, how far would it go before it lands ?
>
>Eastern Atlantic ? Europe ? Russia/Middle East ? Asia/Australia ?
>Pacific ? California ?
>

Atlantic Ocean.

>
>Now, if we forget the wings:
>
>What if stage1 accelerated a bit and made it to the Coast of California
>and landed in Hawthorne ? Would that cost more fuel than fuel needed to
>put on the brakes and accelerate westwards back to KSC/barge ?
>

Yes, because that implies that you've put the first stage virtually
into orbit.

>
>I understand the logistics of wanting it to land near the USA. Landing
>in Middle east would require hefty transportation back to USA. But if
>you went around the world once would that save fuel while giving you
>logistics advantage of landing near SpaceX's California facility ?
>

If you went around the world once you would be a single stage to orbit
vehicle and there aren't any of those with practical payloads.

>
>> If you go that route, you have paid a
>> double mass penalty for recovery (once for wings and a second time for a
>> fuel reserve).
>
>Shuttle: because it was a LOX/LH2 vehicle, the wings were empty.
>
>What if Stage1's wings become kerosene tanks just like in airliners ?
>The wings would no longer be dead weight. They may end up being heavier
>tank than current design, but if extra weight is less than weight of
>fuel to land, it could be a net gain.
>

And if we had magic unicorns we wouldn't bother with rockets.

[ji...@specsol.spam.sux.com]

In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:

That is just stupid; they are unlikely to ever go into production.

For the anal, production is when you can call up the company and
have their product delivered, which is not the SpaceX business
model.

--
Jim Pennino

[Fred J. McCall]

Jeff Findley <jfin...@cinci.nospam.rr.com> wrote:

>In article <576b49b3$0$9153$c3e8da3$5d8f...@news.astraweb.com>,
>jfmezei...@vaxination.ca says...
>>
>> On 2016-06-22 21:57, Jeff Findley wrote:
>>
>> > instead use it to make up for the performance shortfall. Yes, it turns
>> > the reusable into an expendable, but the primary mission succeeds and
>> > places the customer's payload in the desired orbit.
>>
>> Not a problem now, but should launch business become highly competitive
>> and forces SpaceX to price launches based on assumption of recovering
>> stage, then events where the stage is not recovered may generate red ink
>> in the financial statements.
>
>Not really. The stages aren't that expensive to build, because they're
>making money now and aren't counting on reuse yet. And they still have
>a huge launch backlog that will take years to make up. So, losing a few
>stages here and there won't hurt them one bit. On the contrary, not
>underperforming on the primary mission would be *worse* for business,
>since that would impact the customers directly!
>

Mr Mezei also misses the fact that you don't price based on 'assuming'
future performance, but rather based on present performance. If you
don't have stages to reuse, you don't sell reused stages. It's really
that simple.

Just by the way, Musk's numbers in this regard just don't quite seem
to hang together to me. A new first stage costs $18 million
(presumably his cost). A full up launch (all costs, including
profits) costs $60 million. Musk has said that using a reflown first
stage will reduce the price by around $20 million. That seems to say
that, at least initially, if you go on a reflown first stage he'll
give it to you for free.

Of course, if you actually do refly that stage ten times, the cost
over those launches for the first stage is only around $2 million per
launch.

>
>Perhaps, sometime in the far distant future, this might impact them if
>the competition is also reusing their stages and they get into a price
>war with each other. But that is likely 5 to 10 years away, and in the
>meantime, SpaceX will continue to innovate. So who knows where we'll be
>then.
>

I somehow doubt that anything Mr Mezei postulates is ever going to
come to pass.

>> > You simply can't do that with a winged return vehicle unless you also
>> > keep a fuel reserve on board.
>>
>> Say the Falcon9 were in the shape of the Concorde with wings having mass
>> of just 1kg. (aka: mythical no weight penalty).
>
>I'm not going to engage in this sort of senseless speculation. Wings
>are heavy and also impose a significant drag penalty during launch.
>They are inferior to vertical landing for unmanned stage recovery as
>long as you're willing to accept that you'll lose a stage from time to
>time.
>

And since wings are going to be 'dead stick' single pass if you don't
also reserve fuel, you're going to lose a stage from time to time that
way, too.

>> > If you go that route, you have paid a
>> > double mass penalty for recovery (once for wings and a second time for a
>> > fuel reserve).
>>
>> Shuttle: because it was a LOX/LH2 vehicle, the wings were empty.
>>
>> What if Stage1's wings become kerosene tanks just like in airliners ?
>> The wings would no longer be dead weight. They may end up being heavier
>> tank than current design, but if extra weight is less than weight of
>> fuel to land, it could be a net gain.
>
>Wings are far more heavy (kg of wing mass per liter of storage volume)
>than cylindrical tanks. This is basic geometry. Spheres are the most
>mass efficient, but don't make for good aerodynamics, so cylinders are
>the second most mass efficient, so that's what is used.
>

Dammit, there you go clouding the issues with facts again...


--
"Well, I met a girl in West Hollywood. I ain't naming names.
She really worked me over good. She was just like Jesse James.
She really worked me over good. She was a credit to her gender.
She put me through some changes, Lord.
Sort of like a Waring blender."
-- Warren Zevon, "Poor, Poor, Pitiful Me"

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>
>>> Most of this is apples and oranges as Spacex is not producing certified
>>> aircraft.
>>
>>
>> McCall had argued SpaceX can't change its design because it is in
>> production.
>>
>
>That is just stupid; they are unlikely to ever go into production.
>

Yes, it is just stupid. Which is why I never said it.

>
>For the anal, production is when you can call up the company and
>have their product delivered, which is not the SpaceX business
>model.
>

I pointed out to Mr Mezei some time ago that rockets are hand built
and aren't like cars at all. I don't think the boy reads very well.

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>
>><snip>
>>
>>> I claim that something is DESIGNED for a specific minimum performance.
>>
>>Of course it is and based on the knowledge one has at the time.
>>
>>> If that was not true, you would have to tear every airplane down after
>>> every flight, which we obviously do not do.
>>
>>Nope.
>>
>
> Yep. You just agreed, above, Chimp.

Will you be the poster boy for tunnel vision again this year?

>>
>>You test fly the design looking for design discrepancies and errors.
>>
>>After the design is verified, it goes into production and the required
>>periodic inspections may or may not find subtle design flaws such as
>>a gusset that is under strength and needs to be beefed up.
>>
>
> And those 'required periodic inspections' are based on what, Chimp?

History, McCrap.

>>
>>> Mezei claims that you cannot know that you will meet that minimum
>>> performance unless you tear every airplane apart after every flight
>>> and fly them to destruction.
>>
>>I don't care what Mezei claims.
>>
>
> Then why the fuck are you even in this discussion?

Why the fuck do you care?

>>> YOU claim that you get "short maintenance and inspection time
>>> requirements" (that 'minimum performance' I'm talking about) and that
>>> then you do "maintenance and inspection" and that those times MIGHT
>>> lengthen with experience.
>>
>>Nope; the comment was specifically about engines and things like engine
>>part replacement times and engine overhaul times. This is called "service
>>life", not performance.
>>
>
> And "service life" is part of the engineering "design performance",
> Chimpshit.

Nope, two separate, but often, related things, McCrap.



--
Jim Pennino

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:

> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>>
>>>> Most of this is apples and oranges as Spacex is not producing certified
>>>> aircraft.
>>>
>>>
>>> McCall had argued SpaceX can't change its design because it is in
>>> production.
>>>
>>
>>That is just stupid; they are unlikely to ever go into production.
>>
>
> Yes, it is just stupid. Which is why I never said it.

I certainly didn't say you did, McCrap.

>>
>>For the anal, production is when you can call up the company and
>>have their product delivered, which is not the SpaceX business
>>model.
>>
>
> I pointed out to Mr Mezei some time ago that rockets are hand built
> and aren't like cars at all. I don't think the boy reads very well.

Morgan cars are hand built and in production, McCrap.

Being in production has nothing to do with how something is built or
what that something is, McCrap.

--
Jim Pennino

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>> ji...@specsol.spam.sux.com wrote:
>>
>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>
>>><snip>
>>>
>>>> I claim that something is DESIGNED for a specific minimum performance.
>>>
>>>Of course it is and based on the knowledge one has at the time.
>>>
>>>> If that was not true, you would have to tear every airplane down after
>>>> every flight, which we obviously do not do.
>>>
>>>Nope.
>>>
>>
>> Yep. You just agreed, above, Chimp.
>
>Will you be the poster boy for tunnel vision again this year?
>

Lack of response noted.

>>>
>>>You test fly the design looking for design discrepancies and errors.
>>>
>>>After the design is verified, it goes into production and the required
>>>periodic inspections may or may not find subtle design flaws such as
>>>a gusset that is under strength and needs to be beefed up.
>>>
>>
>> And those 'required periodic inspections' are based on what, Chimp?
>
>History, McCrap.
>

Wrong, Chimpshit.

>>>
>>>> Mezei claims that you cannot know that you will meet that minimum
>>>> performance unless you tear every airplane apart after every flight
>>>> and fly them to destruction.
>>>
>>>I don't care what Mezei claims.
>>>
>>
>> Then why the fuck are you even in this discussion?
>
>Why the fuck do you care?
>

Rhetorical question. Look it up.

>>>> YOU claim that you get "short maintenance and inspection time
>>>> requirements" (that 'minimum performance' I'm talking about) and that
>>>> then you do "maintenance and inspection" and that those times MIGHT
>>>> lengthen with experience.
>>>
>>>Nope; the comment was specifically about engines and things like engine
>>>part replacement times and engine overhaul times. This is called "service
>>>life", not performance.
>>>
>>
>> And "service life" is part of the engineering "design performance",
>> Chimpshit.
>
>Nope, two separate, but often, related things, McCrap.
>

Yep, the whole works is 'design performance'. Speaking of 'tunnel
vision', there's your narrow definition of 'performance'.

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>> ji...@specsol.spam.sux.com wrote:
>>
>>>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>>>
>>>>> Most of this is apples and oranges as Spacex is not producing certified
>>>>> aircraft.
>>>>
>>>>
>>>> McCall had argued SpaceX can't change its design because it is in
>>>> production.
>>>>
>>>
>>>That is just stupid; they are unlikely to ever go into production.
>>>
>>
>> Yes, it is just stupid. Which is why I never said it.
>
>I certainly didn't say you did, McCrap.
>

I certainly didn't say you said I did, Chimpshit.

>>>
>>>For the anal, production is when you can call up the company and
>>>have their product delivered, which is not the SpaceX business
>>>model.
>>>
>>
>> I pointed out to Mr Mezei some time ago that rockets are hand built
>> and aren't like cars at all. I don't think the boy reads very well.
>
>Morgan cars are hand built and in production, McCrap.
>

How nice for them. What payload do they have to LEO?

>
>Being in production has nothing to do with how something is built or
>what that something is, McCrap.
>

Where did I say it did, Chimpshit? I know it's difficult for assholes
like you, but try reading the actual words other people say instead of
inserting your own delusions.

Being in production also has nothing to do with whether you can buy
your own personal copy or not. For example, Falcon 9 and Dragon are
both 'in production'. You just get it as a package that includes
launching it for you.

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>> ji...@specsol.spam.sux.com wrote:
>>>
>>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>>
>>>><snip>
>>>>
>>>>> I claim that something is DESIGNED for a specific minimum performance.
>>>>
>>>>Of course it is and based on the knowledge one has at the time.
>>>>
>>>>> If that was not true, you would have to tear every airplane down after
>>>>> every flight, which we obviously do not do.
>>>>
>>>>Nope.
>>>>
>>>
>>> Yep. You just agreed, above, Chimp.
>>
>>Will you be the poster boy for tunnel vision again this year?
>>
>
> Lack of response noted.

I responded but you didn't understand the response.

>>>>
>>>>You test fly the design looking for design discrepancies and errors.
>>>>
>>>>After the design is verified, it goes into production and the required
>>>>periodic inspections may or may not find subtle design flaws such as
>>>>a gusset that is under strength and needs to be beefed up.
>>>>
>>>
>>> And those 'required periodic inspections' are based on what, Chimp?
>>
>>History, McCrap.
>>
>
> Wrong, Chimpshit.

Correct, McCrap.

And there are several kinds of periodic inspections; the minimums
required by the FAA for everybody, additional inspections required by
an AD by the FAA because something was found not to last as long as
expected, and inspections required by the manufacturer during early
fielding of the product.

>>>>> Mezei claims that you cannot know that you will meet that minimum
>>>>> performance unless you tear every airplane apart after every flight
>>>>> and fly them to destruction.
>>>>
>>>>I don't care what Mezei claims.
>>>>
>>>
>>> Then why the fuck are you even in this discussion?
>>
>>Why the fuck do you care?
>>
>
> Rhetorical question. Look it up.
>
>>>>> YOU claim that you get "short maintenance and inspection time
>>>>> requirements" (that 'minimum performance' I'm talking about) and that
>>>>> then you do "maintenance and inspection" and that those times MIGHT
>>>>> lengthen with experience.
>>>>
>>>>Nope; the comment was specifically about engines and things like engine
>>>>part replacement times and engine overhaul times. This is called "service
>>>>life", not performance.
>>>>
>>>
>>> And "service life" is part of the engineering "design performance",
>>> Chimpshit.
>>
>>Nope, two separate, but often, related things, McCrap.
>>
>
> Yep, the whole works is 'design performance'. Speaking of 'tunnel
> vision', there's your narrow definition of 'performance'.

Nope, e.g. how much power an engine puts out is performance, how long
it continues to output that power is service life, McCrap.



--
Jim Pennino

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>> ji...@specsol.spam.sux.com wrote:
>>>
>>>>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>>>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>>>>
>>>>>> Most of this is apples and oranges as Spacex is not producing certified
>>>>>> aircraft.
>>>>>
>>>>>
>>>>> McCall had argued SpaceX can't change its design because it is in
>>>>> production.
>>>>>
>>>>
>>>>That is just stupid; they are unlikely to ever go into production.
>>>>
>>>
>>> Yes, it is just stupid. Which is why I never said it.
>>
>>I certainly didn't say you did, McCrap.
>>
>
> I certainly didn't say you said I did, Chimpshit.

Then why talk to me about it other than to be argumentative, McCrap?

>>>>
>>>>For the anal, production is when you can call up the company and
>>>>have their product delivered, which is not the SpaceX business
>>>>model.
>>>>
>>>
>>> I pointed out to Mr Mezei some time ago that rockets are hand built
>>> and aren't like cars at all. I don't think the boy reads very well.
>>
>>Morgan cars are hand built and in production, McCrap.
>>
>
> How nice for them. What payload do they have to LEO?

Irrelevant; what matters being hand built has nothing to do with
production.

>>Being in production has nothing to do with how something is built or
>>what that something is, McCrap.
>>
>
> Where did I say it did, Chimpshit?

It was implied above in "rockets are hand built" Mc Crap.

<snip ranting bile>

> Being in production also has nothing to do with whether you can buy
> your own personal copy or not. For example, Falcon 9 and Dragon are
> both 'in production'. You just get it as a package that includes
> launching it for you.

The word production in American English implies continuous manufacture
for sale. SpaceX manufactures as needed for their own use. SpaceX is
selling launch services, not space ships, Space Cadet McCrap.


--
Jim Pennino

[Jeff Findley]

In article <oh2omb1ni0go6dpfs...@4ax.com>,
fjmc...@gmail.com says...

> >> > You simply can't do that with a winged return vehicle unless you also
> >> > keep a fuel reserve on board.
> >>
> >> Say the Falcon9 were in the shape of the Concorde with wings having mass
> >> of just 1kg. (aka: mythical no weight penalty).
> >
> >I'm not going to engage in this sort of senseless speculation. Wings
> >are heavy and also impose a significant drag penalty during launch.
> >They are inferior to vertical landing for unmanned stage recovery as
> >long as you're willing to accept that you'll lose a stage from time to
> >time.
> >
>
> And since wings are going to be 'dead stick' single pass if you don't
> also reserve fuel, you're going to lose a stage from time to time that
> way, too.
>

That and if you do keep a fuel reserve in a winged vehicle and expect to
use it in final approach (i.e. while gliding subsonic) the rocket
engines you used during launch are going to be both horribly overpowered
thrust wise and horribly inefficient fuel consumption wise. So making
good use of that fuel which is reserved for landing is going to be a
challenge. Many past proposals for fly back boosters include turbojet
engines for final approach and landing. Seems rather daft to keep on
adding mass and complexity to a design solve the problems that wings
cause, especially since cost scales with complexity.

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>> ji...@specsol.spam.sux.com wrote:
>>
>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>> ji...@specsol.spam.sux.com wrote:
>>>>
>>>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>>>
>>>>><snip>
>>>>>
>>>>>> I claim that something is DESIGNED for a specific minimum performance.
>>>>>
>>>>>Of course it is and based on the knowledge one has at the time.
>>>>>
>>>>>> If that was not true, you would have to tear every airplane down after
>>>>>> every flight, which we obviously do not do.
>>>>>
>>>>>Nope.
>>>>>
>>>>
>>>> Yep. You just agreed, above, Chimp.
>>>
>>>Will you be the poster boy for tunnel vision again this year?
>>>
>>
>> Lack of response noted.
>
>I responded but you didn't understand the response.
>

Lack of response noted.

>>>>>
>>>>>You test fly the design looking for design discrepancies and errors.
>>>>>
>>>>>After the design is verified, it goes into production and the required
>>>>>periodic inspections may or may not find subtle design flaws such as
>>>>>a gusset that is under strength and needs to be beefed up.
>>>>>
>>>>
>>>> And those 'required periodic inspections' are based on what, Chimp?
>>>
>>>History, McCrap.
>>>
>>
>> Wrong, Chimpshit.
>>
>
>Correct, McCrap.
>

Well of course I'm correct, Chimpshit.

>
>And there are several kinds of periodic inspections; the minimums
>required by the FAA for everybody, additional inspections required by
>an AD by the FAA because something was found not to last as long as
>expected, and inspections required by the manufacturer during early
>fielding of the product.
>

And it's that last set that's based on minimum design performance. You
know, like the ten uses of a Falcon 9 that SpaceX calls out that Mezei
is arguing about.

>
>>>>>> Mezei claims that you cannot know that you will meet that minimum
>>>>>> performance unless you tear every airplane apart after every flight
>>>>>> and fly them to destruction.
>>>>>
>>>>>I don't care what Mezei claims.
>>>>>
>>>>
>>>> Then why the fuck are you even in this discussion?
>>>
>>>Why the fuck do you care?
>>>
>>
>> Rhetorical question. Look it up.
>>
>>>>>> YOU claim that you get "short maintenance and inspection time
>>>>>> requirements" (that 'minimum performance' I'm talking about) and that
>>>>>> then you do "maintenance and inspection" and that those times MIGHT
>>>>>> lengthen with experience.
>>>>>
>>>>>Nope; the comment was specifically about engines and things like engine
>>>>>part replacement times and engine overhaul times. This is called "service
>>>>>life", not performance.
>>>>>
>>>>
>>>> And "service life" is part of the engineering "design performance",
>>>> Chimpshit.
>>>
>>>Nope, two separate, but often, related things, McCrap.
>>>
>>
>> Yep, the whole works is 'design performance'. Speaking of 'tunnel
>> vision', there's your narrow definition of 'performance'.
>
>Nope, e.g. how much power an engine puts out is performance, how long
>it continues to output that power is service life, McCrap.
>

Yep, e.g. both are 'design performance', Chimpshit. Just because you
can call something 'thrust' doesn't make it 'not performance'. Same
with 'service life'. Just because something falls in a category
doesn't make it not 'design performance', which is the whole
enchilada.

[Fred J. McCall]

ji...@specsol.spam.sux.com wrote:

>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>> ji...@specsol.spam.sux.com wrote:
>>
>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>> ji...@specsol.spam.sux.com wrote:
>>>>
>>>>>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>>>>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>>>>>
>>>>>>> Most of this is apples and oranges as Spacex is not producing certified
>>>>>>> aircraft.
>>>>>>
>>>>>>
>>>>>> McCall had argued SpaceX can't change its design because it is in
>>>>>> production.
>>>>>>
>>>>>
>>>>>That is just stupid; they are unlikely to ever go into production.
>>>>>
>>>>
>>>> Yes, it is just stupid. Which is why I never said it.
>>>
>>>I certainly didn't say you did, McCrap.
>>>
>>
>> I certainly didn't say you said I did, Chimpshit.
>
>Then why talk to me about it other than to be argumentative, McCrap?
>

Then why talk to me about it other than to be argumentative,

Chimpshit?

>>>>>
>>>>>For the anal, production is when you can call up the company and
>>>>>have their product delivered, which is not the SpaceX business
>>>>>model.
>>>>>
>>>>
>>>> I pointed out to Mr Mezei some time ago that rockets are hand built
>>>> and aren't like cars at all. I don't think the boy reads very well.
>>>
>>>Morgan cars are hand built and in production, McCrap.
>>>
>>
>> How nice for them. What payload do they have to LEO?
>
>Irrelevant; what matters being hand built has nothing to do with
>production.
>

Irrelevant, since I never said it did.

>>>Being in production has nothing to do with how something is built or
>>>what that something is, McCrap.
>>>
>>
>> Where did I say it did, Chimpshit?
>
>It was implied above in "rockets are hand built" Mc Crap.
>

Oh, it was IMPLIED. In other words, you're listening to the voices in
your head instead of what others say, Chimpshit.

>
><snip ranting bile>
>

Hearing those voices in your head again, I see.

>> Being in production also has nothing to do with whether you can buy
>> your own personal copy or not. For example, Falcon 9 and Dragon are
>> both 'in production'. You just get it as a package that includes
>> launching it for you.
>
>The word production in American English implies continuous manufacture
>for sale. SpaceX manufactures as needed for their own use. SpaceX is
>selling launch services, not space ships, Space Cadet McCrap.
>

The word 'production' in American English MEANS "the action of making
or manufacturing from components or raw materials, or the process of
being so manufactured. "the production of chemical weapons" synonyms:
manufacture, making, construction, building, fabrication, assembly,
creation; mass-production "the production of washing machines"

As you can see, it has nothing to do with 'continuous', nor is there
anything about 'sale', regardless of what the voices in your head are
currently whispering to you, Schizo Chimpshit.


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

[ji...@specsol.spam.sux.com]

Nope, McCrap, you are wrong.

Do you think the FAA sets inspection times arbitrarily or do you think
the times are based on some historical data?

>>
>>And there are several kinds of periodic inspections; the minimums
>>required by the FAA for everybody, additional inspections required by
>>an AD by the FAA because something was found not to last as long as
>>expected, and inspections required by the manufacturer during early
>>fielding of the product.
>>
>
> And it's that last set that's based on minimum design performance. You
> know, like the ten uses of a Falcon 9 that SpaceX calls out that Mezei
> is arguing about.

The arguement you started was about generalities, not some specific
of SpaceX, McCrap.

Straight from the McCrap unabridged dictionary...


--
Jim Pennino

[ji...@specsol.spam.sux.com]

In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
> ji...@specsol.spam.sux.com wrote:
>
>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>> ji...@specsol.spam.sux.com wrote:
>>>
>>>>In sci.physics Fred J. McCall <fjmc...@gmail.com> wrote:
>>>>> ji...@specsol.spam.sux.com wrote:
>>>>>
>>>>>>In sci.physics JF Mezei <jfmezei...@vaxination.ca> wrote:
>>>>>>> On 2016-06-22 19:31, ji...@specsol.spam.sux.com wrote:
>>>>>>>
>>>>>>>> Most of this is apples and oranges as Spacex is not producing certified
>>>>>>>> aircraft.
>>>>>>>
>>>>>>>
>>>>>>> McCall had argued SpaceX can't change its design because it is in
>>>>>>> production.
>>>>>>>
>>>>>>
>>>>>>That is just stupid; they are unlikely to ever go into production.
>>>>>>
>>>>>
>>>>> Yes, it is just stupid. Which is why I never said it.
>>>>
>>>>I certainly didn't say you did, McCrap.
>>>>
>>>
>>> I certainly didn't say you said I did, Chimpshit.
>>
>>Then why talk to me about it other than to be argumentative, McCrap?
>>
>
> Then why talk to me about it other than to be argumentative,
> Chimpshit?

You started, again, McCrap.

>>>>>>
>>>>>>For the anal, production is when you can call up the company and
>>>>>>have their product delivered, which is not the SpaceX business
>>>>>>model.
>>>>>>
>>>>>
>>>>> I pointed out to Mr Mezei some time ago that rockets are hand built
>>>>> and aren't like cars at all. I don't think the boy reads very well.
>>>>
>>>>Morgan cars are hand built and in production, McCrap.
>>>>
>>>
>>> How nice for them. What payload do they have to LEO?
>>
>>Irrelevant; what matters being hand built has nothing to do with
>>production.
>>
>
> Irrelevant, since I never said it did.

Then why bring up hand built in the first place, McCrap, or are you going
to lie and say you didn't?

>>>>Being in production has nothing to do with how something is built or
>>>>what that something is, McCrap.
>>>>
>>>
>>> Where did I say it did, Chimpshit?
>>
>>It was implied above in "rockets are hand built" Mc Crap.
>>
>
> Oh, it was IMPLIED. In other words, you're listening to the voices in
> your head instead of what others say, Chimpshit.

"I pointed out to Mr Mezei some time ago that rockets are hand built...".

Your words, McCrap. If hand built is of no significance, why bring it
up at all, McCrap?

>><snip ranting bile>
>>
>
> Hearing those voices in your head again, I see.

Nope, just no point to responding to ranting bile and name calling.

>>> Being in production also has nothing to do with whether you can buy
>>> your own personal copy or not. For example, Falcon 9 and Dragon are
>>> both 'in production'. You just get it as a package that includes
>>> launching it for you.
>>
>>The word production in American English implies continuous manufacture
>>for sale. SpaceX manufactures as needed for their own use. SpaceX is
>>selling launch services, not space ships, Space Cadet McCrap.
>>
>
> The word 'production' in American English MEANS "the action of making
> or manufacturing from components or raw materials, or the process of
> being so manufactured. "the production of chemical weapons" synonyms:
> manufacture, making, construction, building, fabrication, assembly,
> creation; mass-production "the production of washing machines"
>
> As you can see, it has nothing to do with 'continuous', nor is there
> anything about 'sale', regardless of what the voices in your head are
> currently whispering to you, Schizo Chimpshit.

The suffix "ing" in making and manufacturing implies an on going action,
McCrap.

As for sale, why else would a company be manufacturing something on
an on going basis, McCrap?



--
Jim Pennino

[JF Mezei]

On 2016-06-23 18:58, ji...@specsol.spam.sux.com wrote:
> SpaceX manufactures as needed for their own use. SpaceX is
> selling launch services, not space ships, Space Cadet McCrap.

Obviously the case for commercial launches. But what about NASA
launches to ISS ? I assume NASA buys the Dragon spacecraft and owns it?

What about stage2 and stage1 ? Do they remain SpaceX property despite
being lauched by NASA ?

Or does KSC and Houston mission controls really just play an observer
role in this and Hawthorne is the real driver seat ?

(NASA TV seems to make it look like KSC and Houston play a major role
with Hawthorne just "monitoring things".

[JF Mezei]

re: rockets being hand built.

Just because there are humans in the production line doesn't mean
something is hand built.


Not sure if SpaceX uses carbon fabric or carbon threads to do its carbon
structures. With carbon threads, you have to have a robot lay the
thread (pre=preg with epoxy) on the mandrel in a precise layup
(directions, number of layers that intersec each other at specific
angles etc). Humans cannot achieve this. (the 787 fuselage is built that
way).

With fabric, more human intervention is possible on positioning the
fabric layers over mandrel and then wrapping it in bag and using vacuum
pumps to draw the epoxy everywhere without any air bubbles.

Building the engines cannot be done by hand as it requires computer
precision. So a human may be pushing buttons, but a machine makes the
shapes very precisely.


Not sure how SpaceX puts the fuselage of rockets together. Is it single
piece cylinders on top of each other held with rivets ? In this case,
manual riveting is possible, but so is robotic. (Airbus has robotic
riveting for most of its planes).

[Jeff Findley]

In article <576df2f3$0$62137$b1db1813$19ac...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> re: rockets being hand built.
>
> Just because there are humans in the production line doesn't mean
> something is hand built.
>
>
> Not sure if SpaceX uses carbon fabric or carbon threads to do its carbon
> structures. With carbon threads, you have to have a robot lay the
> thread (pre=preg with epoxy) on the mandrel in a precise layup
> (directions, number of layers that intersec each other at specific
> angles etc). Humans cannot achieve this. (the 787 fuselage is built that
> way).

Their tanks are certainly an aluminum lithium alloy. I'm unsure about
the rest of the structure of the stages, but I'd guess aluminum there
too. Flights which use a fairing use a composite payload fairing.

Reference (found in 10 seconds of Googling, because it was the first
link at the top of my first search):

Falcon 9 Payload User's Guide
http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_
2.0.pdf

> With fabric, more human intervention is possible on positioning the
> fabric layers over mandrel and then wrapping it in bag and using vacuum
> pumps to draw the epoxy everywhere without any air bubbles.
>
> Building the engines cannot be done by hand as it requires computer
> precision. So a human may be pushing buttons, but a machine makes the
> shapes very precisely.

I wouldn't say "cannot" because machinists in the aerospace industry
have quite mad skills. There's a reason they're paid quite well. But
yes, I'm sure SpaceX has automated as much as they can during production
because it's more efficient and can be more precise.

> Not sure how SpaceX puts the fuselage of rockets together. Is it single
> piece cylinders on top of each other held with rivets ? In this case,
> manual riveting is possible, but so is robotic. (Airbus has robotic
> riveting for most of its planes).

OMFG! Read the PDF above. Lots of info in there. Google is your
friend!

[Jeff Findley]

In article <576df025$0$25299$c3e8da3$e408...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-23 18:58, ji...@specsol.spam.sux.com wrote:
> > SpaceX manufactures as needed for their own use. SpaceX is
> > selling launch services, not space ships, Space Cadet McCrap.
>
>
> Obviously the case for commercial launches. But what about NASA
> launches to ISS ? I assume NASA buys the Dragon spacecraft and owns it?

Wrong. They're buying cargo delivery service. That's kind of the whole
point of "commercial cargo". Paying for services instead of hardware
that NASA middle management will want to micro-manage (at a very high
cost).

> What about stage2 and stage1 ? Do they remain SpaceX property despite
> being lauched by NASA ?
>
> Or does KSC and Houston mission controls really just play an observer
> role in this and Hawthorne is the real driver seat ?

NASA does not launch *any* Falcons. Mission control for Falcon is is
Hawthorne California. Watch the live stream of a launch sometime!

> (NASA TV seems to make it look like KSC and Houston play a major role
> with Hawthorne just "monitoring things".

Don't watch NASA TV. Watch the SpaceX live-stream!

[JF Mezei]

On 2016-06-25 08:54, Jeff Findley wrote:
> http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_
> 2.0.pdf

Thanks. To show that there are continual improvements instead of fixed
design:
##
As of summer 2015, Falcon 9 is upgraded from its previous v1.1
configuration (flown from 2013 – summer 2015). Unused margin on the
engines has been released to increase thrust. The airframe and thrust
structures have been reinforced to accommodate the additional thrust and
increase reliability. The upgraded vehicle also includes first-stage
recovery systems, to allow SpaceX to return the first stage to the
launch site after completion of primary mission requirements.
##


However, while that document mentions the tanks are aluminium/lithium, I
didn't see the nature of the outer skin. But did find a reference to "

"Falcon 9’s walls are made of aluminum-lithium alloy, a material made
stronger and lighter than aluminum by the addition of lithium."

But just after that:

"Inside the two stages are two large tanks each capped with an aluminum
dome, which store liquid oxygen and rocket-grade kerosene (RP-1) engine
propellants.

So it isn't clear to me if the skin of the stage 1 is the tank or if it
is a skin over the tank.


The Interstage and payload are documented as composite skins.

I recall seeing large composite structures in some photos of SpaceX
facilities. I was under the impression that SpaceX had extensive use of
composites for the rocket.


Cool that they have pneumatic systems instead of pyrothecnic for both
the release from launch pad and for stage separation.

[JF Mezei]

On 2016-06-25 08:57, Jeff Findley wrote:

> Wrong. They're buying cargo delivery service. That's kind of the whole
> point of "commercial cargo".

But NASA sent a whole boat load of cash to SpaceX to build a number of
Dragons for the COTS project. And if you look at their requirement that
manned Dragons land in water, it appears to me that they are buying more
than taxi service.

> NASA does not launch *any* Falcons. Mission control for Falcon is is
> Hawthorne California. Watch the live stream of a launch sometime!

I have watched both NASA and SpaceX streams. And NASA really puts
emphasis on its mission control crews being in control and Hawthorne
just "monitoring".

If we hear "hold hold hold" just before launch, is that a SpaceX
employee or NASA one ? Would it be fair to state that NASA employees
are involved for weather and launch pad ? (or is that the airforce
employees ?) AKA: when SpaceX contracts to launch from Cape Canaveral,
is the contract with military or with NASA ?


In terms of approach to the station. after Dragon has gone into "safe"
station keeping, I take it that NASA is the one who authorizes final
approach ? Does NASA send the command to Dragon to proceed with final
approach, or does SPaceX send the command ?

[Jeff Findley]

In article <576ecbba$0$10146$c3e8da3$fdf4...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-25 08:54, Jeff Findley wrote:
> > http://www.spacex.com/sites/spacex/files/falcon_9_users_guide_rev_
> > 2.0.pdf
>
> Thanks. To show that there are continual improvements instead of fixed
> design:
> ##
> As of summer 2015, Falcon 9 is upgraded from its previous v1.1

> configuration (flown from 2013 ? summer 2015). Unused margin on the

> engines has been released to increase thrust. The airframe and thrust
> structures have been reinforced to accommodate the additional thrust and
> increase reliability. The upgraded vehicle also includes first-stage
> recovery systems, to allow SpaceX to return the first stage to the
> launch site after completion of primary mission requirements.
> ##

Except that increase in thrust likely didn't require any hardware
changes. The increase was quite likely done in software based on hard
data from many ground tests and many Falcon 9 flights. That's not quite
the same as changing the design. It's literally just tapping into
"unused margin on the engines".

> However, while that document mentions the tanks are aluminium/lithium, I
> didn't see the nature of the outer skin. But did find a reference to "

Likely because there is no external skin, except on the parts of the
vehicle between the tanks, over the thrust structure, and between the
stages. Surely the LOX tanks are insulated, but I don't know the
details if there is insulation covered by an external skin (unlikely) or
if the LOX tank has external spray on foam insulation (more likely) or
something else.

> "Falcon 9?s walls are made of aluminum-lithium alloy, a material made

> stronger and lighter than aluminum by the addition of lithium."
>
> But just after that:
>
> "Inside the two stages are two large tanks each capped with an aluminum
> dome, which store liquid oxygen and rocket-grade kerosene (RP-1) engine
> propellants.
>
> So it isn't clear to me if the skin of the stage 1 is the tank or if it
> is a skin over the tank.

They're describing the end caps of the tanks. There likely is no outer
skin over the tanks. Likely just a layer of insulation over the LOX

tank.

> The Interstage and payload are documented as composite skins.

Ok.

> I recall seeing large composite structures in some photos of SpaceX
> facilities. I was under the impression that SpaceX had extensive use of
> composites for the rocket.

the biggest composite bits are for the payload fairing, which is quite
large. The interstage is indeed made of composites. The landing legs
are carbon composite and aluminum honeycomb.

Since I work for Siemens PLM Software, I know they use our software to
design the composite structures:

SpaceX, Leading space-launch company cuts development time from 70 to 85
percent with Fibersim

https://www.plm.automation.siemens.com/CaseStudyWeb/dispatch/viewResourc
e.html?resourceId=29661

> Cool that they have pneumatic systems instead of pyrothecnic for both
> the release from launch pad and for stage separation.

Because pneumatic systems are inherently reusable. Pyros are not only
"one time use", but can cause collateral damage. Great for separating
ICBM stages, but not so great if you plan on reusing the first stage.

[Jeff Findley]

In article <576ecded$0$1532$c3e8da3$12bc...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

>
> On 2016-06-25 08:57, Jeff Findley wrote:
>
> > Wrong. They're buying cargo delivery service. That's kind of the whole
> > point of "commercial cargo".
>
> But NASA sent a whole boat load of cash to SpaceX to build a number of
> Dragons for the COTS project. And if you look at their requirement that
> manned Dragons land in water, it appears to me that they are buying more
> than taxi service.

NASA paid for SpaceX to meet milestones, but they do not own the
hardware. The proof is that the first flown Dragon capsules are hanging
from the ceiling at their Hawthorne California site. If NASA owned
them, they'd be property of the Smithsonian and would either be in one
of their D.C. facilities, or on loan to a NASA museum.

> > NASA does not launch *any* Falcons. Mission control for Falcon is is
> > Hawthorne California. Watch the live stream of a launch sometime!
>
> I have watched both NASA and SpaceX streams. And NASA really puts
> emphasis on its mission control crews being in control and Hawthorne
> just "monitoring".

Really? I'd certainly like a cite for this one. I could see NASA might
want some control over Dragon, especially close to ISS, but Falcon?
Seems quite hard to believe.

> If we hear "hold hold hold" just before launch, is that a SpaceX
> employee or NASA one ? Would it be fair to state that NASA employees
> are involved for weather and launch pad ? (or is that the airforce
> employees ?) AKA: when SpaceX contracts to launch from Cape Canaveral,
> is the contract with military or with NASA ?

Actually, range safety is done by USAF. To date, all Falcons launched
from Florida have been launched from Cape Canaveral Air Force Station,
not from NASA's Kennedy Space Center. This will change a bit when their
KSC pad starts launching Falcons, but I'm sure SpaceX is in control of
their launch vehicles. They're not at all owned by NASA.

> In terms of approach to the station. after Dragon has gone into "safe"
> station keeping, I take it that NASA is the one who authorizes final
> approach ? Does NASA send the command to Dragon to proceed with final
> approach, or does SPaceX send the command ?

I'm sure NASA has a hand in controlling Dragon as it approaches ISS.
NASA is surely the one calling *those* station keeping holds. But
Falcon is the launch vehicle, which is completely different.

[Greg (Strider) Moore]

"JF Mezei" wrote in message
news:576ecded$0$1532$c3e8da3$12bc...@news.astraweb.com...

>
>On 2016-06-25 08:57, Jeff Findley wrote:
>
>> Wrong. They're buying cargo delivery service. That's kind of the whole
>> point of "commercial cargo".
>
>But NASA sent a whole boat load of cash to SpaceX to build a number of
>Dragons for the COTS project. And if you look at their requirement that
>manned Dragons land in water, it appears to me that they are buying more
>than taxi service.

No, they're just specifying a town car instead of a yellow cab, so SpaceX is
probably charging a bit more.

>
>
>> NASA does not launch *any* Falcons. Mission control for Falcon is is
>> Hawthorne California. Watch the live stream of a launch sometime!
>
>I have watched both NASA and SpaceX streams. And NASA really puts
>emphasis on its mission control crews being in control and Hawthorne
>just "monitoring".
>
>If we hear "hold hold hold" just before launch, is that a SpaceX
>employee or NASA one ? Would it be fair to state that NASA employees
>are involved for weather and launch pad ? (or is that the airforce
>employees ?) AKA: when SpaceX contracts to launch from Cape Canaveral,
>is the contract with military or with NASA ?

My guess is the only person outside SpaceX who has any authority at the Cape
is the Range Safety Officer, and that's AR.

>
>
>In terms of approach to the station. after Dragon has gone into "safe"
>station keeping, I take it that NASA is the one who authorizes final
>approach ? Does NASA send the command to Dragon to proceed with final
>approach, or does SPaceX send the command ?

I'm almost positive SpaceX does.

>

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

[JF Mezei]

On 2016-06-25 16:43, Greg (Strider) Moore wrote:

>>In terms of approach to the station. after Dragon has gone into "safe"
>>station keeping, I take it that NASA is the one who authorizes final
>>approach ? Does NASA send the command to Dragon to proceed with final
>>approach, or does SPaceX send the command ?
>
> I'm almost positive SpaceX does.

Can't remember if this was for Dragon or the japanese one. But one of
the procedures was for station crews to send a command to the nearby
ship to turn on a light as confirmation they had a working data link and
could remotely control the ship if necesssary (such as call for
emergency "get away" command.).

This would imply that SpaceX has given NASA the means to access Dragon's
command and control.


So if I get this right, NASA is totally out of the loop for the launch
from Cape Canaveral and it is only the Air Force (owner of the facility
and controller of range safety) that would have a say for launch,
correct ? So if NASA-TV shows the KSC or Houston control rooms, it is
just to pretend they are involved ?

[Jeff Findley]

In article <576f547d$0$31266$c3e8da3$dd96...@news.astraweb.com>,
jfmezei...@vaxination.ca says...

I'm sure they're involved, as in monitoring the launch and monitoring
Dragon. And most certainly they're going to put a feed of the launch on
NASA TV. But, NASA quite simply does not buy Falcons or Dragons and
take control of operating them from launch to landing.

Instead, NASA buys cargo delivery services to ISS. It's up to SpaceX
and Orbital ATK to get the cargo to the ISS. This is why it's called
"commercial cargo". And this is why it's so much cheaper than having
NASA do everything.

[Greg (Strider) Moore]

"JF Mezei" wrote in message

news:576f547d$0$31266$c3e8da3$dd96...@news.astraweb.com...

>
>On 2016-06-25 16:43, Greg (Strider) Moore wrote:
>
>>>In terms of approach to the station. after Dragon has gone into "safe"
>>>station keeping, I take it that NASA is the one who authorizes final
>>>approach ? Does NASA send the command to Dragon to proceed with final
>>>approach, or does SPaceX send the command ?
>>
>> I'm almost positive SpaceX does.
>
>
>Can't remember if this was for Dragon or the japanese one. But one of
>the procedures was for station crews to send a command to the nearby
>ship to turn on a light as confirmation they had a working data link and
>could remotely control the ship if necesssary (such as call for
>emergency "get away" command.).
>
>This would imply that SpaceX has given NASA the means to access Dragon's
>command and control.
>

I do seem to recall NASA having some sort of "abort" capability, but that's
about it.

>
>So if I get this right, NASA is totally out of the loop for the launch
>from Cape Canaveral and it is only the Air Force (owner of the facility
>and controller of range safety) that would have a say for launch,
>correct ? So if NASA-TV shows the KSC or Houston control rooms, it is
>just to pretend they are involved ?
>

Oh, I'm sure they're involved. If there's anomalous condition, I'm sure NASA
wants a heads up as early as possible.
To make up an example (I have no clue is this is an actual case) Dragon ends
up in a lower than normal orbit and SpaceX wants to use onboard reserves to
fix the problem, NASA will want to evaluate that to know if there's enough
margin for proximity ops.

or to make up another example, if the Dragon experiences higher than normal
transient g forces (let's say a Merlin starts to pogo for some strange,
unknown reason), again NASA may want to know as soon as possible.

[Dr J R Stockton]

In sci.astro message <MPG.31d9f99a7...@news.eternal-
september.org>, Sun, 26 Jun 2016 15:40:00, Jeff Findley
<jfin...@cinci.nospam.rr.com> posted:

>
>Instead, NASA buys cargo delivery services to ISS. It's up to SpaceX
>and Orbital ATK to get the cargo to the ISS. This is why it's called
>"commercial cargo". And this is why it's so much cheaper than having
>NASA do everything.

Does this SpaceX commercial service actually pay for the resources it
uses at CCAFS? It should, as Orbital ATK uses Wallops which seems to
belong to Virginia and some future SpaceX flights will use SpaceX's own
probably-cheaper Brownsville resources.


--
(c) John Stockton, Surrey, UK. 拯merlyn.demon.co.uk Turnpike v6.05 MIME.
Merlyn Web Site < > - FAQish topics, acronyms, & links.