What are the chances of the Falcon 9 blowing up too?
> 27 engines vs. 30 engines (First stage)
>
> What are the chances of the Falcon 9 blowing up too?
>
I'd say chances are far better of a successful F9 Heavy launch since
its components are going to be much better tested in the medium version
first.
But the first Heavy will likely have a substantial pucker factor.
--Damon
Apples and orangutans. The Russians were really pushing the schedule for
the N-1 due to the moon race. The Americans were doing the same with Saturn
V and were lucky that the incidents they had didn't destroy the vehicle.
The Saturn V POGO problems got really close to disaster on at least one
flight.
> What are the chances of the Falcon 9 blowing up too?
Depens on how reliable a single engine is, then you can use statistics to
figure out the chance of engine failure. Even so, liquid engine failures
are usually benign. With nine engines on each core, you simply shut the
malfunctioning engine and continue the mission. Luckily for SpaceX, they're
not in a race with the Russians and can take their time with testing. ;-)
Jeff
--
"Take heart amid the deepening gloom
that your dog is finally getting enough cheese" - Deteriorata - National
Lampoon
Actually, I think they are in an even more difficult race - a race
with their funding.
rick jones
--
web2.0 n, the dot.com reunion tour...
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...
>> What are the chances of the Falcon 9 blowing up too?
>
> Depens on how reliable a single engine is, then you can use statistics to
> figure out the chance of engine failure. Even so, liquid engine failures
> are usually benign. With nine engines on each core, you simply shut the
> malfunctioning engine and continue the mission. Luckily for SpaceX, they're
> not in a race with the Russians and can take their time with testing. ;-)
Additionally the Russians did never test the N-1 first stage prior to
launch, while SpaceX already did a full test for the F-9 first stage.
This is not to say that the Falcon 9 (Heavy) can't fail, but it has a
much higher chance not to fail than the N-1.
Jochem
--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery
> "Jeff Findley" <jeff.f...@ugs.nojunk.com> writes:
>
> >> What are the chances of the Falcon 9 blowing up too?
> >
> > Depens on how reliable a single engine is, then you can use statistics to
> > figure out the chance of engine failure. Even so, liquid engine failures
> > are usually benign. With nine engines on each core, you simply shut the
> > malfunctioning engine and continue the mission. Luckily for SpaceX, they're
> > not in a race with the Russians and can take their time with testing. ;-)
>
> Additionally the Russians did never test the N-1 first stage prior to
> launch, while SpaceX already did a full test for the F-9 first stage.
There's also a considerable difference between feeding 30 engines from
a single set of tanks and feeding each group of nine engines from its
own set of tanks. The more complex the plumbing, the more potential
problems there are.
Anthony
>There's also a considerable difference between feeding 30 engines from
>a single set of tanks and feeding each group of nine engines from its
>own set of tanks. The more complex the plumbing, the more potential
>problems there are.
Not that 3 sets of plumbing each serving 'x' engines is actually less
complex than 1 set serving 3'x' engines.
D.
--
Touch-twice life. Eat. Drink. Laugh.
http://derekl1963.livejournal.com/
-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL
>Depens on how reliable a single engine is, then you can use statistics to
>figure out the chance of engine failure. Even so, liquid engine failures
>are usually benign. With nine engines on each core, you simply shut the
>malfunctioning engine and continue the mission.
And hope the wiring didn't get botched between the controllers and all
those engines, resulting in a good engine being turned off and the bad
one going kablooey.
Brian
I'd say there are better strategies available to avoid that than "hope"...
That particular Russian failure ought to have been caught during pre-launch
testing, but they were in a race to beat the Americans and corners were cut
in the name of time. Hopefully SpaceX is more detail oriented than the
Russians were during the space race.
>
> "Brian Thorn" <btho...@suddenlink.net> wrote in message
> news:rhb4f5he1cge0sogl...@4ax.com...
>> On Wed, 4 Nov 2009 11:16:19 -0500, "Jeff Findley"
>> <jeff.f...@ugs.nojunk.com> wrote:
>>
>>
>>>Depens on how reliable a single engine is, then you can use
>>>statistics to figure out the chance of engine failure. Even so,
>>>liquid engine failures are usually benign. With nine engines on each
>>>core, you simply shut the malfunctioning engine and continue the
>>>mission.
>>
>> And hope the wiring didn't get botched between the controllers and
>> all those engines, resulting in a good engine being turned off and
>> the bad one going kablooey.
>
> That particular Russian failure ought to have been caught during
> pre-launch testing, but they were in a race to beat the Americans and
> corners were cut in the name of time. Hopefully SpaceX is more detail
> oriented than the Russians were during the space race.
Hasn't that scenario already been tested on the ground with Falcon 9?
Engines will normally be shut down near the end of the first stage
burn to limit acceleration and shutdown transients.
I'd like to think communications between the flight controller and
individual engine controllers will more sophisticated than the N-1
apparently was.
--Damon
I don't think the "sophistication" of an engine controller matters if the
guys assembling the rocket stage don't plug the right connectors into the
right sockets. Getting your "wires crossed" in this manner can have
disastrous consequences, so you would want to run tests on the ground before
you launch the thing.
>
>"Brian Thorn" <btho...@suddenlink.net> wrote in message
>news:rhb4f5he1cge0sogl...@4ax.com...
>> On Wed, 4 Nov 2009 11:16:19 -0500, "Jeff Findley"
>> <jeff.f...@ugs.nojunk.com> wrote:
>>
>>
>>>Depens on how reliable a single engine is, then you can use statistics to
>>>figure out the chance of engine failure. Even so, liquid engine failures
>>>are usually benign. With nine engines on each core, you simply shut the
>>>malfunctioning engine and continue the mission.
>>
>> And hope the wiring didn't get botched between the controllers and all
>> those engines, resulting in a good engine being turned off and the bad
>> one going kablooey.
>
>That particular Russian failure ought to have been caught during pre-launch
>testing, but they were in a race to beat the Americans and corners were cut
>in the name of time. Hopefully SpaceX is more detail oriented than the
>Russians were during the space race.
Yet, the detail oriented Americans made an equally significant wiring
error on AS-502.
That doesn't seem to directly relate to complex wiring harnesses on
expendable vehicles which are hand built due to very low production rates.
> What if the flight controls on that jetliner you're riding
> are reversed?
Every time I've flown with a pilot friend of mine, he runs through a
pre-flight check which would catch this problem. Neglecting to perform
basic pre-flight checks is especially foolish when you've never flown that
particular aircraft before (which is the case for every launch of an
expendable vehicle).
> Some things are just preposterous to worry about.
Hope is not a satisfactory substitute for a quality assurance program.
True, and hopefully you learn from such early failures (this was only the
second, unmanned, flight test of the Saturn V).
Hand wired expendable launch vehicles such as these really ought to be
better tested before they're flown. Unfortunately, there are some things
that you simply can't test without flying. Every flight is the first flight
for an expendable, so infant mortality problems such as these become
especially troublesome.
>> And hope the wiring didn't get botched between the controllers and all
>> those engines, resulting in a good engine being turned off and the bad
>> one going kablooey.
>
>That particular Russian failure ought to have been caught during pre-launch
>testing, but they were in a race to beat the Americans and corners were cut
>in the name of time. Hopefully SpaceX is more detail oriented than the
>Russians were during the space race.
It almost happened to Saturn V AS-502 also, the bad engine shut down
on its own, fortunately. And Martin-Marietta botched the wiring on
Commercial Titan III because they got the single payload/dual payload
setup reversed.
Brian
I'd by concerned about that many engines generating some pretty involved
harmonic effects.
Pat
All four N=1 failures were due to different causes, not some fundamental
flaw in the engines.
Pat
N-1 plumbing was a complex and heavy mess with so many long pipes being
involved that it was almost begging for some pipe or weld seam to fail
under launch vibration.
Pat
The joys of KORD, a "reliability-improving" system that seemed almost
designed to cause a rocket to fail:
http://catless.ncl.ac.uk/Risks/21.53.html#subj4
Pat
Ariane V failed during its first launch when the guidance system
reverted into a ground test configuration during flight.
Pat
But all were due to a flaw in the first stage which could have been
caught with full testing. They did never (to my knowlegde) a full
vibration test, a fuel flow test or (god forbid) a test with all engines
running for the full duration of the first stage burn.
All of that has been done with the Falcon 9 first stage, though. All
engines running with a full first stage attached for the full duration
of a real launch. This still leaves the aerodynamic effects out, but I
would say that there's about an order of magnitude more confidence in
the thing than in the N-1 now.
>But all were due to a flaw in the first stage which could have been
>caught with full testing. They did never (to my knowlegde) a full
>vibration test, a fuel flow test or (god forbid) a test with all engines
>running for the full duration of the first stage burn.
...Correct. About the only static testing they did was individual
engines, and possibly 2-3 engines in cluster. The issue was secrecy,
in that either a static test of the full 30+ engine cluster and/or a
single-stage launch test could/would have been detected by US spy sats
- which is what happened anyway when they rolled the full stack out to
the launch site either the first or second time, there's some debate
about which pad checkout was caught and labled as "TT-5".
OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[
That and I don't think the Soviet Union was ever fully invested in the moon
race. It wasn't important enough for them to focus all of their efforts on
that single space program. They had several different programs going on
internally, so their efforts were always divided. Even their space station
work in the 70's suffered from this. Duplication of effort was rampant in
their space program and I'm not sure it ever completely ended.
It has nothing to do with secrecy. It was money and time, which they
didn't have.
The issue wasn't secrecy, it was cost; They did build a test stand for
the second and third stages, and fired those fully assembled.
Since all three lower stages used differing numbers (30,8,4) of
basically the same rocket engine modified for operation at different
altitudes, and also were similar in design and tankage layout, they
probably thought that the info from the upper stage tests would be
applicable to the first stage without going to the trouble of building a
full-scale test rig for it, saving both time and money.
>> - which is what happened anyway when they rolled the full stack out to
>> the launch site either the first or second time, there's some debate
>> about which pad checkout was caught and labled as "TT-5".
Info on that here:
http://www.globalsecurity.org/intell/library/reports/2004/open-source_imagery_follow-on.htm
>
> That and I don't think the Soviet Union was ever fully invested in the moon
> race. It wasn't important enough for them to focus all of their efforts on
> that single space program.
It was their major program at the time as far as funding went, it's just
that they were going around five different directions at once (manned
landing, unmanned rovers/sample return, civilian space stations,
military space stations, future Mars flights, etc.) rather than zeroing
in on it like we did with Apollo.
They had several different programs going on
> internally, so their efforts were always divided. Even their space station
> work in the 70's suffered from this. Duplication of effort was rampant in
> their space program and I'm not sure it ever completely ended.
The whole works was a complete cocked-up mess from the word go, and a
great example of how not to do things if you want to succeed.
One of the basic problems was the retention of the Stalinist concept of
having at least two design bureaus working on any project in direct
competition to each other, each trying to undermine the other in the
eyes of the government and seize their competitor's funding.
Pat
Sounds like competitive U.S. Military procurement procedures. Do we
have an airborn refueling tanker deal yet?
rick jones
--
No need to believe in either side, or any side. There is no cause.
There's only yourself. The belief is in your own precision. - Joubert
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...
This got a lot more severe; about the closest thing we had to it in our
space program was McDonnell pitching all sorts of modified Gemini
variants in competition to Apollo till NASA told them to cut that crap
out: http://www.astronautix.com/articles/bygemoon.htm
Pat