Cult spacecraft Part One: The Little Spaceplane That Couldn't
dump...@hotmail.com
OM
...Notice who the bottom-burp was that wrote this? Looks like our old
"friend" Jeff Bell is back.
OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[
Jeff Findley
<dump...@hotmail.com> wrote in message
news:08c0a435-a58b-4884...@i20g2000prf.googlegroups.com...
> See:
>
> http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little_Spaceplane_That_Could_Not_999.html
You left out "by Jeffrey F. Bell". To quote Jamie (of Mythbusters), "Well
there's your problem!"
Jeff
--
beb - To paraphrase Stephen Colbert, reality has an anti-Ares I bias.
Jeff Findley
"OM" <om@all_trolls_must_DIE.com> wrote in message
news:9h0fj49c4va88h0il...@4ax.com...
> On Wed, 3 Dec 2008 21:05:24 -0800 (PST), dump...@hotmail.com wrote:
>
>>See:
>>
>>http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little_Spaceplane_That_Could_Not_999.html
>
> ...Notice who the bottom-burp was that wrote this? Looks like our old
> "friend" Jeff Bell is back.
My thoughts exactly. While the article is an interesting read, it's
definately an editorial rant by Jeffrey Bell.
Jeff Findley
Pat Flannery
dump...@hotmail.com wrote:
> See:
>
> http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little_Spaceplane_That_Could_Not_999.html
>
"If X-20 had actually flown in the late 1960s, that instrumentation
would have supplied the Shuttle's designers with a priceless data base.
They would not have been forced to rely completely on wind-tunnel data
and primitive computer models and would have produced a better design.
For instance, the Orbiters carry two tons of lead blocks in their noses
to compensate for an error in aerodynamic models, and X-20 data might
well have prevented this mistake."
Is it true that the orbiters carry that much nose ballast?
If it is, then one of the criticisms (weight/CG concerns) of installing
escape capsules for the crew after Challenger (
http://www.spaceref.com/news/viewnews.html?id=780 ) gets reduced in
viability.
I'm really looking forward to the rest of this series.
Pat
BradGuth
> See:
>
> http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Litt...
"So this is my own alternate aerospace history fantasy: If there had
been a few X-20 flights, and the data base from these flights had been
available in 1971, it is possible that we could have avoided the whole
Space Shuttle fiasco? Might we have stuck with capsules instead of
getting lost in a blind alley? Could Dyna-Soar have saved us 14 dead
astronauts and over $100B of wasted money? Could we have spent the
last 35 years doing something useful in space, if that useless little
black spaceplane had actually flown?"
Of so much need-to-know, and of these badly inflated and energy
resource deficient days there's no time or public loot to spare. The
same can be said of Russia and a dozen other cloak and dagger nations
that are all trying to screw one another, even if it kills themselves
in the process.
~ BG
BradGuth
> dumpst...@hotmail.com wrote:
> > See:
>
> >http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Litt...
>
> would have supplied the Shuttle's designers with a priceless data base.
> They would not have been forced to rely completely on wind-tunnel data
> and primitive computer models and would have produced a better design.
> For instance, the Orbiters carry two tons of lead blocks in their noses
> to compensate for an error in aerodynamic models, and X-20 data might
> well have prevented this mistake."
>
> Is it true that the orbiters carry that much nose ballast?
> If it is, then one of the criticisms (weight/CG concerns) of installing
> viability.
> I'm really looking forward to the rest of this series.
>
> Pat
What truth(s) are you talking about?
Are you suggesting that our nation of fly-by-rocket wizards has actual
truths to behold?
Odd, since you'd much rather believe in and promote their lies as
supposed truth.
Why don't you start asking questions and otherwise naming names, dates
and places that need to be disclosed?
~ Brad Guth Brad_Guth Brad.Guth BradGuth BG / “Guth Usenet”
Pat Flannery
Jeff Findley wrote:
> You left out "by Jeffrey F. Bell". To quote Jamie (of Mythbusters), "Well
> there's your problem!"
>
The only thing I found new in that article was the Shuttle ballast
weights; other than that I had known about the rest of the Dyna-Soar's
problems before reading it.
As he pointed out, it should have been built... as after looking at how
well it worked (particularly what turn-around time and costs between
missions would have been like) we might have extrapolated from it and
seen the Shuttle was a flawed concept from the word go.
I'm sure Project Orion is going to show up in this series shortly; that
should be a ball from the viewpoint of the R&D cost projections they
came up with alone.
They are going to develop a multi-crewed interplanetary spaceship
powered by nuclear explosions, and it's going to cost around 1.5 billion
dollars total...or to put it another way, less than 1/12th the cost of
Project Apollo in 1969 dollars (20-25 billion dollars).
Yeah, fer sure. :-D
The problem I have with Mythbusters is that a lot of times they do
something sort of like what the myth says, but greatly simplified, and
then draw conclusions from that.
Case in point was the "Jaws" show, where they shot the scuba tank with a
rifle to show that it wouldn't explode and blow the shark up like in the
movie...it didn't... but it did take off like a rocket from the
compressed air venting through the bullet hole.
In the movie, the tank is in the shark's mouth with the base (where the
bullet hits) facing forward.
So when it's hit, it's going to go flying straight down into the shark's
innards venting air at 2-3,000 psi.
That air is going to want to go somewhere in a hurry, and surrounded by
the shark's body and seawater it's going to be tamped like the expanding
gases of gunpowder in the barrel of a gun. So it might create a very
large increase in internal pressure in the shark in a very short period
of time, causing it to explode - just like in the movie.
So how do you test this to see what happens?
You get a big dead shark, you stick a filled scuba tank in its mouth
base outwards, you semi-submerge it in the ocean, and you shoot the tank
in its base with a high powered rifle and watch what happens.
If you are going to go mythbusting, do it right.
Pat
Rick Jones
> That air is going to want to go somewhere in a hurry, and surrounded
> by the shark's body and seawater it's going to be tamped like the
> expanding gases of gunpowder in the barrel of a gun. So it might
> create a very large increase in internal pressure in the shark in a
> very short period of time, causing it to explode - just like in the
> movie.
Or a large shark burp...
rick jones
--
denial, anger, bargaining, depression, acceptance, rebirth...
where do you want to be today?
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...
OM
wrote:
>I'm really looking forward to the rest of this series.
...I'm not. Instead of a decent, informative historical article, it's
typical Anti-NASA Jeff Bell bullshit. The guy's as bad as Elfnazi or
Brad Guth in his vendetta against NASA and all manned space
exploration, and has the sad distinction of also being given a
professional platform upon which to vent his hatred. Bell needs to do
the same thing Keith Cowing needs to do: shut the hell up and go away.
jacob navia
> On Thu, 04 Dec 2008 06:43:38 -0600, Pat Flannery <fla...@daktel.com>
> wrote:
>
>> I'm really looking forward to the rest of this series.
>
> ...I'm not. Instead of a decent, informative historical article, it's
> typical Anti-NASA Jeff Bell bullshit. The guy's as bad as Elfnazi or
> Brad Guth in his vendetta against NASA and all manned space
> exploration, and has the sad distinction of also being given a
> professional platform upon which to vent his hatred. Bell needs to do
> the same thing Keith Cowing needs to do: shut the hell up and go away.
>
>
> OM
Wait a minute. The guy says in essence that wings are heavy, need
special sophisticated cooling, and that a ballistic reentry capsule
is obviously much more efficient.
I do not see any "hate" here but a very good argument that is confirmed
by experience: the U.S. is abandoning the glided reentry concept and the
russians never pursued it fully, sticking to their much simpler vehicles
that have so far provoked much less deaths than the shuttle concept.
You are just taking it to easy. Have you any argument to put forward?
--
jacob navia
jacob at jacob point remcomp point fr
logiciels/informatique
http://www.cs.virginia.edu/~lcc-win32
Damon Hill
news:08c0a435-a58b-4884...@i20g2000prf.googlegroups.com:
> See:
>
> http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little
> _Spaceplane_That_Could_Not_999.html
>
Compare the Soviet equivalent:
http://www.russianspaceweb.com/spiral_development.html
Think it might have worked better? The Mach 6 motherplane was
likely an unworkable boondoggleski, but the orbiter portion
seemed at least marginally doable and wasn't it flown in scale
model form?
It didn't stop the Soviets from building a Shuttle clone, either.
--Damon
Totorkon
> dumpst...@hotmail.com wrote:
> > See:
>
> >http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Litt...
>
> would have supplied the Shuttle's designers with a priceless data base.
> They would not have been forced to rely completely on wind-tunnel data
> and primitive computer models and would have produced a better design.
> For instance, the Orbiters carry two tons of lead blocks in their noses
> to compensate for an error in aerodynamic models, and X-20 data might
> well have prevented this mistake."
>
> Is it true that the orbiters carry that much nose ballast?
> If it is, then one of the criticisms (weight/CG concerns) of installing
> viability.
> I'm really looking forward to the rest of this series.
>
> Pat
That ton of nose ballast may not be entirely fair. In the following
reference it states that:
"The nose wheel well will accomodate 1350 pounds of ballast, and the
Xo378 bulkhead will accomodate a maximum of 2660 pounds."
It sounds like the amount varies depending on the cargo's mass
distribution and is not a fundamental design flaw.
Pat Flannery
Damon Hill wrote:
> dump...@hotmail.com wrote in
> news:08c0a435-a58b-4884...@i20g2000prf.googlegroups.com:
>
>
>> See:
>>
>> http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little
>> _Spaceplane_That_Could_Not_999.html
>>
>>
>
> Compare the Soviet equivalent:
>
> http://www.russianspaceweb.com/spiral_development.html
>
> Think it might have worked better? The Mach 6 motherplane was
> likely an unworkable boondoggleski, but the orbiter portion
> seemed at least marginally doable and wasn't it flown in scale
> model form?
>
Piloted non-orbital prototype, photos, plans, and films of it in flight
here: http://www.buran.ru/htm/epos.htm
Project was canceled due to cost in 1968 by Minister of Defense
Gretchko, with statement: "We will not engage in nonsense".
> It didn't stop the Soviets from building a Shuttle clone, either.
>
They knew ours would never work economically compared to expendable
boosters, so assumed it had a hidden military purpose...probably as a
orbital bomber.
So they built theirs as a reply to it, including a planned orbital
bomber version: http://www.buran.su/
When we saw the photos of the landed BOR lifting body floating in the
Pacific, we though it might be a maneuvering RV of some type to attack
targets from orbit...guess what, we were right:
http://www.buran.fr/bourane-buran/img/bor_bur.jpg
Pat
Damon Hill
news:7sGdnU2DpODTnqTU...@posted.northdakotatelephone:
>
>
> Damon Hill wrote:
>
>> It didn't stop the Soviets from building a Shuttle clone, either.
>>
>
> They knew ours would never work economically compared to expendable
> boosters, so assumed it had a hidden military purpose...probably as a
> orbital bomber.
I've never understood that thinking. A Shuttle launch is about as
non-subtle as it gets, and kicking stuff out an open payload bay
door at orbital or near-orbital velocity and expecting it fall on the
target is silly.
At any rate, once Vandenberg was abandoned, that rationale for Buran
pretty much evaporated even if Buran itself didn't until the whole
economic/political system went down the drain. And they still float
rumors about reviving it (though I don't believe them for a second).
> So they built theirs as a reply to it, including a planned orbital
> bomber version: http://www.buran.su/
> When we saw the photos of the landed BOR lifting body floating in the
> Pacific, we though it might be a maneuvering RV of some type to attack
> targets from orbit...guess what, we were right:
> http://www.buran.fr/bourane-buran/img/bor_bur.jpg
Again, while its conceivable that a tungsten carbide rod embedded in
a maneuvering RV is capable of doing real damage to any ship, it's
less than an elegant solution that an ICBM reentry vehicle wouldn't
improve upon.
Seems to me a manned orbital spacecraft is exactly what it seems to
be.
Quack, quack, quack-ski.
--Damon, waiting to see if Jeff Bell includes Energia/Buran in his list
Pat Flannery
Damon Hill wrote:
> I've never understood that thinking. A Shuttle launch is about as
> non-subtle as it gets, and kicking stuff out an open payload bay
> door at orbital or near-orbital velocity and expecting it fall on the
> target is silly.
>
For some reason, after their Nazi allies sent Stukas after their
airfields in June of 1941the Russians have been paranoid about things
unexpectedly coming out of the sky at them. :-)
> At any rate, once Vandenberg was abandoned, that rationale for Buran
> pretty much evaporated even if Buran itself didn't until the whole
> economic/political system went down the drain. And they still float
> rumors about reviving it (though I don't believe them for a second).
>
That was one of the things that may have led to the closing of
Vandenberg... the Russians started dropping hints that if they ever saw
a Shuttle heading into a polar orbit that would pass over Russia they
were going to destroy it without warning.
It's also what got the Spiral program restarted for a while using a
Zenit booster instead of the carrier aircraft to get it into orbit, as
they were thinking of having any Vandenberg shuttle missions that would
pass over Russia be escorted by a Spiral derivatives or new space
fighter design with its weapons aimed at it:
http://www.astronautix.com/craft/uraeptor.htm
The story goes that both sides realized this was all getting pretty
silly, dangerous, and expensive, so they backed down on the
military-related polar Shuttle missions.
>
>> So they built theirs as a reply to it, including a planned orbital
>> bomber version: http://www.buran.su/
>> When we saw the photos of the landed BOR lifting body floating in the
>> Pacific, we though it might be a maneuvering RV of some type to attack
>> targets from orbit...guess what, we were right:
>> http://www.buran.fr/bourane-buran/img/bor_bur.jpg
>>
>
> Again, while its conceivable that a tungsten carbide rod embedded in
> a maneuvering RV is capable of doing real damage to any ship, it's
> less than an elegant solution that an ICBM reentry vehicle wouldn't
> improve upon.
>
Oh, those little things back weren't going to have tungsten rods in
them, they were going to have thermonuclear warheads in them. The
lifting body shape was to give them cross range and the ability to
outmaneuver ABMs. the "cockpit windows" were where the sensors went that
would allow them to home on their targets.
One of the ideas for Spiral was to nuke carrier task forces from orbit,
as shown in one of the embedded videos on this page:
http://www.buran.ru/htm/spiral_5.htm#war Top left: photorecon; top
right: SAR recon (?); bottom left: naval attack; bottom right: space
interception.
But again, it was a pretty expensive and obtuse way of doing something
fairly simple, that would probably best be accomplished in a unmanned form.
Chelomoie's "Kosmoplan" was a interesting concept - although stated to
be for flying a spacecraft around Mars...with a "Shaddock" cruise
missile in it (!), the actual plan was to put these in Earth orbit, from
where they could descend _inside of_ America's ICBM radar warning screen
range and then release their cruise missiles to fly to their targets at
low altitude.
Pat
Rick Jones
> For some reason, after their Nazi allies sent Stukas after their
> airfields in June of 1941the Russians have been paranoid about
> things unexpectedly coming out of the sky at them. :-)
You mean like Cesnas?-)
rick jones
--
the road to hell is paved with business decisions...
Rand Simberg
Flannery <fla...@daktel.com> made the phosphor on my monitor glow in
such a way as to indicate that:
>
>
>Damon Hill wrote:
>> I've never understood that thinking. A Shuttle launch is about as
>> non-subtle as it gets, and kicking stuff out an open payload bay
>> door at orbital or near-orbital velocity and expecting it fall on the
>> target is silly.
>>
>
>For some reason, after their Nazi allies sent Stukas after their
>airfields in June of 1941the Russians have been paranoid about things
>unexpectedly coming out of the sky at them. :-)
>
>> At any rate, once Vandenberg was abandoned, that rationale for Buran
>> pretty much evaporated even if Buran itself didn't until the whole
>> economic/political system went down the drain. And they still float
>> rumors about reviving it (though I don't believe them for a second).
>>
>
>That was one of the things that may have led to the closing of
>Vandenberg... the Russians started dropping hints that if they ever saw
>a Shuttle heading into a polar orbit that would pass over Russia they
>were going to destroy it without warning.
Yes.
Right.
That's why we gave up on Shuttle out of Vandenberg...
<rolling eyes at Pat's lunacy>
Fred J. McCall
:
:That was one of the things that may have led to the closing of
:a Shuttle heading into a polar orbit that would pass over Russia they
:were going to destroy it without warning.
I don't find that particularly credible, given Open Skies and all
that.
What killed Vandenberg was cost plus down time of the Shuttle after
challenger. That's when the USAF expendable booster program started
back up.
--
"Rule Number One for Slayers - Don't die."
-- Buffy, the Vampire Slayer
SEN...@argo.rhein-neckar.de
>> It didn't stop the Soviets from building a Shuttle clone, either.
>>
>
>They knew ours would never work economically compared to expendable
>boosters, so assumed it had a hidden military purpose...probably as a
>orbital bomber.
No Pat, nothing like that. Something more sophisticated.
## CrossPoint v3.12d R ##
Monte Davis
>It sounds like the amount varies depending on the cargo's mass
>distribution and is not a fundamental design flaw.
Ummm... given the total mass of the orbiter (and the range of other
components which could have been modified or designed for
re-positioning to achieve the same effective moment), I don't see what
else you could possibly call it.
If you want to label it an *unavoidable* flaw, in the sense that the
need for it was not foreseeable early enough, fine -- but it's hard to
see non-functional mass, taken to orbit at a cost (pro-rated) of
millions or tens of millions per flight, as a feature.
Monte Davis
>For some reason, after their Nazi allies sent Stukas after their
>airfields in June of 1941the Russians have been paranoid about things
>unexpectedly coming out of the sky at them. :-)
In't it fortunate that the foolish habit of drawing bogus analogies
between the military usefulness of aeronautics and the military
usefulness of space never got any traction outside the USSR?
Monte Davis
>One of the ideas for Spiral was to nuke carrier task forces from orbit...
Since RORSATs (plus our equivalents) and Command Data Buffers -> RECT
(plus Soviet equivalents) were deployed, it's been obvious -- if
unpalatable to admirals -- that any carrier task force is very
vulnerable to a triplet of 200KT ICBM warheads. (Or two triplets, or
three... the cost tradeoff remains very attractive.) Flank speed
simply isn't all that fast, even with the maximum possible warning
time.
As in so many other cases, the "success" of the initial Cold War
sprint to ICBMs was so complete that it undercut the rationale for a
lot of sexier (read "piloted") milspace.
Pat Flannery
Rick Jones wrote:
> Pat Flannery <fla...@daktel.com> wrote:
>
>> For some reason, after their Nazi allies sent Stukas after their
>> airfields in June of 1941the Russians have been paranoid about
>> things unexpectedly coming out of the sky at them. :-)
>>
>
> You mean like Cesnas?-)
>
>
>
Yeah, those in particular. :-D
So, what happened to Mathias Rust after that?:
http://english.pravda.ru/russia/history/30-05-2007/92461-red_square-0
Hooliganism is a life-long curse!
Meanwhile...cosmonauts experience _Space Madness_!:
http://english.pravda.ru/society/anomal/28-11-2008/106764-soviet_ufo-0
"Psychologists often warn cosmonauts prior to their space missions that
they may experience a phenomenon known as the altered state of
consciousness. A Russian cosmonaut said in 1994 that he and his partner
had numerous visions when they were working on board the Mir station for
six months. It seemed to them that they were turning into weird
creatures – animals and even humanoids of extraterrestrial origin."
Isn't there a STNG episode about something like this happening?
Worf turns into a crab, and Data becomes a UNIVAC?
Pat
Fred J. McCall
:Pat Flannery <fla...@daktel.com> wrote:
:>
:>One of the ideas for Spiral was to nuke carrier task forces from orbit...
:>
:
:Since RORSATs (plus our equivalents) and Command Data Buffers -> RECT
:(plus Soviet equivalents) were deployed, it's been obvious -- if
:unpalatable to admirals -- that any carrier task force is very
:vulnerable to a triplet of 200KT ICBM warheads. (Or two triplets, or
:three... the cost tradeoff remains very attractive.) Flank speed
:simply isn't all that fast, even with the maximum possible warning
:time.
:
What are you assuming is "the maximum possible warning time"?
Totorkon
At arocket, under the thread heading of 'X20 analysis', Henry Spencer
wrote:
"Ballast is an inelegant solution, to be sure, but it is simple and
cheap..."
I would like to see documentation that settles the issue of whether
the 'accomodation' of ballast resulted from design error or design
flexibility.
Pat Flannery
Fred J. McCall wrote:
> :Since RORSATs (plus our equivalents) and Command Data Buffers -> RECT
> :(plus Soviet equivalents) were deployed, it's been obvious -- if
> :unpalatable to admirals -- that any carrier task force is very
> :vulnerable to a triplet of 200KT ICBM warheads. (Or two triplets, or
> :three... the cost tradeoff remains very attractive.) Flank speed
> :simply isn't all that fast, even with the maximum possible warning
> :time.
> :
>
> What are you assuming is "the maximum possible warning time"?
>
That would depend on the time from retro burn to impact for a system
striking from orbit.
Since there would be no crew aboard G forces aren't a concern, so how
fast you can get it to the target depends on the overall thermal effects
it can withstand and how big of a velocity shift the retro engine can
impart to it.
In the case of the BOR lifting body RVs shown leaving the Buran cargo
bay in the bomber mode, they are supposed to home on their targets after
reentry via internal sensors.
Assuming 1/2 hour from retrofire to impact, then a carrier task force
could get around 15-18 nautical miles from its position at retrofire
(assuming that it's going at 30-35 knots).
That would be a survivable distance for a multi-megaton thermonuclear
strike, but it presupposes two things:
1.) That the warhead is aimed at its current position, and doesn't
incorerate a "lead" factor of where it's going to be in a half hour's time.
2.) That the retroburn can be detected, allowing the carrier force to
immediatly turn around 180 degrees and flee at flank speed. If the RV is
indeed "leading" the target, this could be quite effective in getting
the ships out of its way.
However, if the RV has a lifting body design and a homing capability,
then the movement the target can accomplish after retrofire probably
isn't going to be enough to get it out of the cross range footprint of
the incoming warhead.
Pat
Fred J. McCall
:
:Fred J. McCall wrote:
:> :Since RORSATs (plus our equivalents) and Command Data Buffers -> RECT
:> :(plus Soviet equivalents) were deployed, it's been obvious -- if
:> :unpalatable to admirals -- that any carrier task force is very
:> :vulnerable to a triplet of 200KT ICBM warheads. (Or two triplets, or
:> :three... the cost tradeoff remains very attractive.) Flank speed
:> :simply isn't all that fast, even with the maximum possible warning
:> :time.
:> :
:>
:> What are you assuming is "the maximum possible warning time"?
:>
:
:That would depend on the time from retro burn to impact for a system
:striking from orbit.
Which is part of why I asked the question. I can't tell what
assumptions are made.
:
:Since there would be no crew aboard G forces aren't a concern, so how
:fast you can get it to the target depends on the overall thermal effects
:it can withstand and how big of a velocity shift the retro engine can
:impart to it.
:In the case of the BOR lifting body RVs shown leaving the Buran cargo
:bay in the bomber mode, they are supposed to home on their targets after
:reentry via internal sensors.
:Assuming 1/2 hour from retrofire to impact, then a carrier task force
:could get around 15-18 nautical miles from its position at retrofire
:(assuming that it's going at 30-35 knots).
:That would be a survivable distance for a multi-megaton thermonuclear
:strike, but it presupposes two things:
:
When did we elevate from 200kt to "multi-megaton"?
:
:1.) That the warhead is aimed at its current position, and doesn't
:incorerate a "lead" factor of where it's going to be in a half hour's time.
:
Which assumes there is no early warning time and that the CVBG stays
'straight and stupid', maintaining SOA.
:
:2.) That the retroburn can be detected, allowing the carrier force to
:immediatly turn around 180 degrees and flee at flank speed. If the RV is
:indeed "leading" the target, this could be quite effective in getting
:the ships out of its way.
:
The retroburn is probably more detectable than the carrier is, so the
'warning time' comes down to how fast these things can reenter, as you
already noted.
:
:However, if the RV has a lifting body design and a homing capability,
:then the movement the target can accomplish after retrofire probably
:isn't going to be enough to get it out of the cross range footprint of
:the incoming warhead.
:
Homing on movers is hard. The target has to be detectable within the
seeker FOV. Note where the little sensor windows are. They're there
for things like celestial nav, not to act as seekers against moving
targets.
'Look down' sensors aren't going to be able to see through your TPS,
which means that even if they exist they cannot be deployed until
these things are relatively 'low and slow'.
--
"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
Greg D. Moore (Strider)
Given the size of the payload bay and the requirements of the craft, the
ability to adjust the COG sort of comes with the territory.
That said, I think the COG ended up being further back than originally
estimated so more ballast than originally planned for.
--
Greg Moore
Ask me about lily, an RPI based CMC.
"Totorkon" <aert...@gmail.com> wrote in message
news:43410d79-bdcb-4209...@c36g2000prc.googlegroups.com...
Reunite Gondwanaland (Mary Shafer)
wrote:
>
>
> dump...@hotmail.com wrote:
> > See:
> >
> > http://www.space-travel.com/reports/Cult_spacecraft_Part_One_The_Little_Spaceplane_That_Could_Not_999.html
> >
>
> "If X-20 had actually flown in the late 1960s, that instrumentation
> would have supplied the Shuttle's designers with a priceless data base.
> They would not have been forced to rely completely on wind-tunnel data
> and primitive computer models and would have produced a better design.
> For instance, the Orbiters carry two tons of lead blocks in their noses
> to compensate for an error in aerodynamic models, and X-20 data might
> well have prevented this mistake."
No, it wouldn't. CFD is no better than wind tunnels at getting trim
alpha right. Everyone knows that. Sometimes they get it so wrong
they have to change the angle of the horizontal stabilizers or even
the wing. This is a major structural change, so adding a little
ballast is a much easier solution.
Although the ballast may be there because other equipment, installed
further aft, turned out heavier than expected. The 747 carries a ton
or two of depleted uranium ballast in its nose, for example. Some of
it is because of added equipment, since by the -400 they had a pretty
good idea of the trim alpha.
> Is it true that the orbiters carry that much nose ballast?
The amount may well vary depending on payload. That's probably a
maximum. I wonder why they use lead instead of something denser, like
depleted uranium.
> If it is, then one of the criticisms (weight/CG concerns) of installing
> escape capsules for the crew after Challenger (
> http://www.spaceref.com/news/viewnews.html?id=780 ) gets reduced in
> viability.
The ballast may not be removable if you want the trim alpha the
vehicle was designed for. The ejection seats may not be heavy enough
or far enough forward. Remember that delta-wings have an odd center
of rotation, too, which couples with the center of gravity.
Surely I'm not the only one who knows such basic aerodynamics and
history here. I thought everyone knew about trim alpha, just as
everyone knows about real aircraft having more drag than predicted.
Mary "Not even an aerodynamicist"
--
Mary Shafer Retired aerospace research engineer
We didn't just do weird stuff at Dryden, we wrote reports about it.
reunite....@gmail.com or mil...@qnet.com
Visit my blog at http://thedigitalknitter.blogspot.com/
Jorge R. Frank
I think the masses quoted for the forward ballast boxes are just the
maximum. In my memory (going back to the first RTF), there hasn't been a
flight that has needed forward ballast. Usually it's the opposite
problem. The nominal CG is roughly 3/4 aft in the payload bay, so the
payload can shift the CG forward enough that *aft* ballast is needed to
keep the CG within the box. Especially so for ISS flights since the ODS
is mounted forward in the bay. For ISS flights, we don't even load the
FRCS pod full of propellant - typical loading is 70% - and we dump the
entire remaining FRCS load after deorbit.
>> If it is, then one of the criticisms (weight/CG concerns) of installing
>> escape capsules for the crew after Challenger (
>> http://www.spaceref.com/news/viewnews.html?id=780 ) gets reduced in
>> viability.
Nope. See above. Escape capsules shift the CG forward.
Pat Flannery
Fred J. McCall wrote:
>
> When did we elevate from 200kt to "multi-megaton"?
>
Where exactly did the 200 KT estimate come from?
The Soviets were noted for sticking the biggest yield warheads possible
on their SLBMs to make up for any error distance during descent to
their targets due to position uncertainties at launch. They were aimed
at soft targets like cities and airfields.
Given the fact that a terminally unguided attack on a naval target would
involve a substantial miss distance in any case, they would stick the
biggest warhead possible on it...probably 1-5 megatons - a
thermonuclear warhead with a two stage secondary fusion section.
Overall weight of that wouldn't be at all that high given present
technology.
It would also probably detonate underwater to generate the shockwaves to
destroy its targets by caving their hulls in.
> :
> :1.) That the warhead is aimed at its current position, and doesn't
> :incorerate a "lead" factor of where it's going to be in a half hour's time.
> :
>
> Which assumes there is no early warning time and that the CVBG stays
> 'straight and stupid', maintaining SOA.
>
Yeah, but you've got to pick up the deorbit burn to alert the carrier
group about what's coming.
And that deorbit burn is going to occur around 1/3 of the way around the
Earth from where the carrier attack group is.
Well outside the range of any organic detection by their radar or sensors.
So it's got to go through channels to them once its spotted. Right there
you lose around 5 minutes warning time minimum for detection,
confirmation, transmission to the ships, and and the ships acting on the
message.
Anyway, this is something that never got deployed by either side, so any
discussion of the tactical aspects of its operation are pretty much
pointless when it comes right down to it from other than a theoretical
point of view.
The costs of setting up a 24/7/365 manned orbital bomber force in all
orbital inclinations to attack any naval target at sea anywhere in the
world at any time would make SAC's "Chrome Dome" look like something you
could do with your weekly allowance.
> :
> :2.) That the retroburn can be detected, allowing the carrier force to
> :immediatly turn around 180 degrees and flee at flank speed. If the RV is
> :indeed "leading" the target, this could be quite effective in getting
> :the ships out of its way.
> :
>
> The retroburn is probably more detectable than the carrier is, so the
> 'warning time' comes down to how fast these things can reenter, as you
> already noted.
>
> :
> :However, if the RV has a lifting body design and a homing capability,
> :then the movement the target can accomplish after retrofire probably
> :isn't going to be enough to get it out of the cross range footprint of
> :the incoming warhead.
> :
>
> Homing on movers is hard. The target has to be detectable within the
> seeker FOV. Note where the little sensor windows are. They're there
> for things like celestial nav, not to act as seekers against moving
> targets.
>
> 'Look down' sensors aren't going to be able to see through your TPS,
> which means that even if they exist they cannot be deployed until
> these things are relatively 'low and slow'.
>
What if the RCC nosecap separates after reentry to reveal a radar antenna?
In fact, wouldn't the radar be able to go _clean through_ the
non-metallic RCC nosecap?
Pat
Pat Flannery
Reunite Gondwanaland (Mary Shafer) wrote:
> No, it wouldn't. CFD is no better than wind tunnels at getting trim
> alpha right. Everyone knows that. Sometimes they get it so wrong
> they have to change the angle of the horizontal stabilizers or even
> the wing. This is a major structural change, so adding a little
> ballast is a much easier solution.
>
> Although the ballast may be there because other equipment, installed
> further aft, turned out heavier than expected. The 747 carries a ton
> or two of depleted uranium ballast in its nose, for example. Some of
> it is because of added equipment, since by the -400 they had a pretty
> good idea of the trim alpha.
>
The problem was with Dyna-Soar we really didn't have any firm data on
what a object entering the atmosphere from orbit was going to encounter
on the way down in regards to aerodynamic effects if it intended to fly
in.... as opposed to just come down ballisticlly, like a warhead.
Heating, hypersonic shockwave impingement details, and Reynolds numbers
couldn't be figured out without real-world tests at the time, which is
why the X-15 almost sawed the dummy scramjet off of its ventral fin when
the plasma flow from the nose shockwave hit the leading edge of the fin
while flying at full tilt.
We did do tests of the front end of a Dyna-Soar during reentry under
Asset: http://www.astronautix.com/craft/asset.htm
But trying to figure out the center of lift movement in going from
subsonic to supersonic flight was pretty tough indeed without throwing
going from Mach 24 to subsonic flight into the mix.
Asset avoided that problem by going out of control while still
supersonic during its flight tests, but Dyna-Soar didn't have that
luxury. Those drop tests from a B-52 would have been vital to figuring
out its subsonic aspects, but seeing how it behaved all the way down
from orbit to landing would have meant unmanned orbital tests for
safety's sake.
Even the Shuttle suffered from a real problem regarding computer
simulations versus actual flight performance, particularly in regards to
aerodynamic interactions between the SRB/ET stack and the orbiter during
ascent.
After Challenger, there was a plan (that wasn't implemented) to stick
upper wing spoilers on the orbiters to cut down excessive lift that
their wings were generating during ascent, thereby increasing drag on
the stack as it had to angle itself to compensate for the sideways
motion that the lift was causing.
After the computer advances between 1960-1980, seeing the things that
the slide-ruler approach to the X-20 would have led to in regards to its
ability to come down in a planned area would have been fascinating, to
say the least... :-D
Pat
Pat Flannery
Jorge R. Frank wrote:
>
>>> If it is, then one of the criticisms (weight/CG concerns) of
>>> installing escape capsules for the crew after Challenger (
>>> http://www.spaceref.com/news/viewnews.html?id=780 ) gets reduced in
>>> viability.
>
> Nope. See above. Escape capsules shift the CG forward.
Yes, but that's the idea... you stick them in, and you turn the need for
nose ballast into a need for no ballast, or rear ballast; while not
upping the total overall weight as much as just adding the escape
capsules would in the case of a nose-ballasted flight.
Anyway, the whole concept was a non-starter...it would have cost a lot
of money and grounded the fleet for around 2-3 years easy. Of course,
done concurrent with the SRB modifications after Challenger it might
have been tolerable from a flight delay aspect - particularly if it had
saved the crew of Columbia - but the whole STS program was such a kludge
from a economic point of view that it might be better if it's
acknowledged as a trip up the wrong road, and goes out of service ASAP
rather than hanging around for another 20 years or so with a viable
escape system.
It's fascinating to think about the fact that when STS got going, it was
supposed to be going out of service around the year 2000, with each
orbiter having made around 100 flights.
What was supposed to have replaced it by now in those halcyon days of
the mid 1970's is a good question.
I assume something like the VentureStar.
Pat
Fred J. McCall
:
:Fred J. McCall wrote:
:>
:> When did we elevate from 200kt to "multi-megaton"?
:>
:
:Where exactly did the 200 KT estimate come from?
From the original statement about 'triads of 200 kt warheads' or some
such. You know. The bit you've snipped off the front.
:
:The Soviets were noted for sticking the biggest yield warheads possible
:on their SLBMs to make up for any error distance during descent to
:their targets due to position uncertainties at launch. They were aimed
:at soft targets like cities and airfields.
:
True, but we're not talking about SLBMs or fixed targets, now are we?
:
:Given the fact that a terminally unguided attack on a naval target would
:involve a substantial miss distance in any case, they would stick the
:biggest warhead possible on it...probably 1-5 megatons - a
:thermonuclear warhead with a two stage secondary fusion section.
:Overall weight of that wouldn't be at all that high given present
:technology.
:
Given present technology, they're using smaller warheads. You're
mixing Soviet practice from 30-40 years ago and then talking "present
technology" out the other side of your mouth.
Pick one.
:
:It would also probably detonate underwater to generate the shockwaves to
:destroy its targets by caving their hulls in.
:
Unlikely, largely because it would probably break up when it hit the
water. Add enough protection to prevent that and you're back to
talking about smaller warheads.
:> :
:> :1.) That the warhead is aimed at its current position, and doesn't
:> :incorerate a "lead" factor of where it's going to be in a half hour's time.
:> :
:>
:> Which assumes there is no early warning time and that the CVBG stays
:> 'straight and stupid', maintaining SOA.
:>
:
:Yeah, but you've got to pick up the deorbit burn to alert the carrier
:group about what's coming.
:
And you think nobody would be watching? That's really quite funny!
:
:And that deorbit burn is going to occur around 1/3 of the way around the
:Earth from where the carrier attack group is.
:Well outside the range of any organic detection by their radar or sensors.
:So it's got to go through channels to them once its spotted. Right there
:you lose around 5 minutes warning time minimum for detection,
:confirmation, transmission to the ships, and and the ships acting on the
:message.
:
The only time lost is the same time lost if you have organic
detection; reacting to the threat.
:
:Anyway, this is something that never got deployed by either side, so any
:discussion of the tactical aspects of its operation are pretty much
:pointless when it comes right down to it from other than a theoretical
:point of view.
:
It makes much, MUCH less sense than what was generally actually done,
which is shadowing forces.
:
:The costs of setting up a 24/7/365 manned orbital bomber force in all
:orbital inclinations to attack any naval target at sea anywhere in the
:world at any time would make SAC's "Chrome Dome" look like something you
:could do with your weekly allowance.
:
Why would they have to be up all the time? Just launch them like you
would launch 'alert bombers'.
:
:> :
:> :2.) That the retroburn can be detected, allowing the carrier force to
:> :immediatly turn around 180 degrees and flee at flank speed. If the RV is
:> :indeed "leading" the target, this could be quite effective in getting
:> :the ships out of its way.
:> :
:>
:> The retroburn is probably more detectable than the carrier is, so the
:> 'warning time' comes down to how fast these things can reenter, as you
:> already noted.
:>
:> :
:> :However, if the RV has a lifting body design and a homing capability,
:> :then the movement the target can accomplish after retrofire probably
:> :isn't going to be enough to get it out of the cross range footprint of
:> :the incoming warhead.
:> :
:>
:> Homing on movers is hard. The target has to be detectable within the
:> seeker FOV. Note where the little sensor windows are. They're there
:> for things like celestial nav, not to act as seekers against moving
:> targets.
:>
:> 'Look down' sensors aren't going to be able to see through your TPS,
:> which means that even if they exist they cannot be deployed until
:> these things are relatively 'low and slow'.
:>
:
:What if the RCC nosecap separates after reentry to reveal a radar antenna?
:
What if it does? By the time you can start shedding things you're
relatively 'low and slow', as I already mentioned.
:
:In fact, wouldn't the radar be able to go _clean through_ the
:non-metallic RCC nosecap?
:
It could presumably be designed that way, but it'd be difficult to
both do thermal protection AND have a radar antenna sitting behind it.
Pat Flannery
Fred J. McCall wrote:
>
> From the original statement about 'triads of 200 kt warheads' or some
> such. You know. The bit you've snipped off the front.
>
That's probably from someone I have killfiled; if you want me to see
it in detail, you had better quote the whole section of text you want
me to reply to.
As to why a RV descending on a carrier group would have yield as small
as 200 kt is completely beyond me.
You increase warhead weight by 50% and now you are dealing with a 2 mt
warhead.
Sounds like a formidable increase in weight until one realizes the low
overall weight increase of a nuclear versus thermonuclear warhead, where
a lot of weight is wrapped up in the fuzzing gear of the primary and its
explosive lens, versus the very small size of the single or dual fusion
sparkplugs.
> ::The Soviets were noted for sticking the biggest yield warheads possible
> :on their SLBMs to make up for any error distance during descent to
> :their targets due to position uncertainties at launch. They were aimed
> :at soft targets like cities and airfields.
> :
>
> True, but we're not talking about SLBMs or fixed targets, now are we?
>
No, of course not. We are talking about thermonuclear bombs out of orbit
onto a moving marine target, so what's your point?
> :
> :Given the fact that a terminally unguided attack on a naval target would
> :involve a substantial miss distance in any case, they would stick the
> :biggest warhead possible on it...probably 1-5 megatons - a
> :thermonuclear warhead with a two stage secondary fusion section.
> :Overall weight of that wouldn't be at all that high given present
> :technology.
> :
>
> Given present technology, they're using smaller warheads. You're
> mixing Soviet practice from 30-40 years ago and then talking "present
> technology" out the other side of your mouth.
>
Wait a second here... this was the Buran orbital bomber concept from the
early 1980's, not today.
That's the period the BOR RV tests came from.
30 years ago.
> Pick one.
>
> :
> :It would also probably detonate underwater to generate the shockwaves to
> :destroy its targets by caving their hulls in.
> :
>
> Unlikely, largely because it would probably break up when it hit the
> water. Add enough protection to prevent that and you're back to
> talking about smaller warheads.
>
If it glides into the water at subsonic speeds; or indeed lets the
warhead proper go in midair so that descends into the water under a
parachute like a ASROC nuclear depth charge, this indeed can occur.
> :> :
> :> :1.) That the warhead is aimed at its current position, and doesn't
> :> :incorerate a "lead" factor of where it's going to be in a half hour's time.
> :> :
> :>
> :> Which assumes there is no early warning time and that the CVBG stays
> :> 'straight and stupid', maintaining SOA.
> :>
> :
> :Yeah, but you've got to pick up the deorbit burn to alert the carrier
> :group about what's coming.
> :
>
> And you think nobody would be watching? That's really quite funny!
>
Oh, of course someone would be watching if this system was ever
deployed...how fast can you get their info back to the fleet and let the
act on it after it goes through the channels from detection, to
confirmation, to action?
I stated that I thought it would be five minutes.
Screw that, let's make it instantaneously.
Your carrier group is moving along at 40 knots... in five minutes you
are going to cover 1/12 of that distance, or to put it another way, you
have a advantage of an extra 3.3 miles between you and the impact point;
assuming of course that you can somehow turn the whole fleet around in
zero time and get it going in the reverse direction.
This is worthless in regards to a RV that can modify its course on the
way down; any maneuvers the naval fleet can accomplish given the warning
of the RV descent and its limited speed are going to ineffectual against
a maneuvering RV that either incorporates organic homing or descent
updates from a RORSAT.
> :
> :And that deorbit burn is going to occur around 1/3 of the way around the
> :Earth from where the carrier attack group is.
> :Well outside the range of any organic detection by their radar or sensors.
> :So it's got to go through channels to them once its spotted. Right there
> :you lose around 5 minutes warning time minimum for detection,
> :confirmation, transmission to the ships, and and the ships acting on the
> :message.
> :
>
> The only time lost is the same time lost if you have organic
> detection; reacting to the threat.
>
> :
> :Anyway, this is something that never got deployed by either side, so any
> :discussion of the tactical aspects of its operation are pretty much
> :pointless when it comes right down to it from other than a theoretical
> :point of view.
> :
>
> It makes much, MUCH less sense than what was generally actually done,
> which is shadowing forces.
>
> :
> :The costs of setting up a 24/7/365 manned orbital bomber force in all
> :orbital inclinations to attack any naval target at sea anywhere in the
> :world at any time would make SAC's "Chrome Dome" look like something you
> :could do with your weekly allowance.
> :
>
> Why would they have to be up all the time? Just launch them like you
> would launch 'alert bombers'.
>
Unmanned, great.
You might be able to pull that off.
Manned Shuttles?
Both we and Russia had a maximum of two operational launchpads that each
would take around a week or two refurbishment between launches if you
pushed it to max effort.
Given that, and the orbital inclinations required to get your orbital
bombers into position 24/7 for a surprise attack, and I sure hope their
crews are keen on eating food out of a tube, as the around 100 shuttles
are going to be on station for around six months to a year each.
> What if it does? By the time you can start shedding things you're
> relatively 'low and slow', as I already mentioned.
>
> :
> :In fact, wouldn't the radar be able to go _clean through_ the
> :non-metallic RCC nosecap?
> :
>
> It could presumably be designed that way, but it'd be difficult to
> both do thermal protection AND have a radar antenna sitting behind it.
>
It's a dielectric; the radar won't even see it.
Pat
Fred J. McCall
:
:
:Fred J. McCall wrote:
:>
:> From the original statement about 'triads of 200 kt warheads' or some
:> such. You know. The bit you've snipped off the front.
:>
:That's probably from someone I have killfiled; if you want me to see
:it in detail, you had better quote the whole section of text you want
:me to reply to.
:
I did, in Message <9c1mj4116blcdmv8d...@4ax.com>. *YOU*
snipped it off; first you clipped the name of the original poster and
then you clipped the paragraph I quoted.
:
:As to why a RV descending on a carrier group would have yield as small
:as 200 kt is completely beyond me.
:You increase warhead weight by 50% and now you are dealing with a 2 mt
:warhead.
:
Yes, and instead of throwing three of them, as the original poster
proposed, now you can only throw one.
:
:Sounds like a formidable increase in weight until one realizes the low
:overall weight increase of a nuclear versus thermonuclear warhead, where
:a lot of weight is wrapped up in the fuzzing gear of the primary and its
:explosive lens, versus the very small size of the single or dual fusion
:sparkplugs.
:
And that increase doesn't sound significant until one starts looking
at typical throw weights. The current Russian ICBM (Topol-M) has a
payload of only 1,000 pounds and carries a single 550kt warhead.
That weight increase also doesn't sound correct, looking at weights of
current US nuclear weapons. For example, two current weapons are the
B-83 and the W-87. The B-83 is variable yield up to 1.2MT and weighs
around 2400 pounds. The W-87 is 300KT and weighs less than 600
pounds. These are two weapons that are modern and recently
manufactured as such things go. They would make it appear that
getting from hundreds of kilotons to megatons is a 400% increase in
weight, not the 50% you claim above.
:> ::The Soviets were noted for sticking the biggest yield warheads possible
:> :on their SLBMs to make up for any error distance during descent to
:> :their targets due to position uncertainties at launch. They were aimed
:> :at soft targets like cities and airfields.
:> :
:>
:> True, but we're not talking about SLBMs or fixed targets, now are we?
:>
:
:No, of course not. We are talking about thermonuclear bombs out of orbit
:onto a moving marine target, so what's your point?
:
My point is that you have to get them up to orbit, acquire moving
targets, then get down from orbit onto those targets. The mission is
nowhere near similar.
:> :
:> :Given the fact that a terminally unguided attack on a naval target would
:> :involve a substantial miss distance in any case, they would stick the
:> :biggest warhead possible on it...probably 1-5 megatons - a
:> :thermonuclear warhead with a two stage secondary fusion section.
:> :Overall weight of that wouldn't be at all that high given present
:> :technology.
:> :
:>
:> Given present technology, they're using smaller warheads. You're
:> mixing Soviet practice from 30-40 years ago and then talking "present
:> technology" out the other side of your mouth.
:>
:
:Wait a second here... this was the Buran orbital bomber concept from the
:early 1980's, not today.
:
Then don't try to wave away how "overall weight of that wouldn't all
that high" by invoking "present technology", since we're talking about
30 years ago and not the present at all.
:
:That's the period the BOR RV tests came from.
:30 years ago.
:
:>
:> Pick one.
:>
:
Ok, so you're going with the 30 years ago.
:> :
:> :It would also probably detonate underwater to generate the shockwaves to
:> :destroy its targets by caving their hulls in.
:> :
:>
:> Unlikely, largely because it would probably break up when it hit the
:> water. Add enough protection to prevent that and you're back to
:> talking about smaller warheads.
:>
:
:If it glides into the water at subsonic speeds; or indeed lets the
:warhead proper go in midair so that descends into the water under a
:parachute like a ASROC nuclear depth charge, this indeed can occur.
:
Water is like stone at "subsonic speeds". Now your reentry vehicle
has to carry a big parachute and it must be capable of retarding the
weapon sufficiently to allow water entry.
:> :> :
:> :> :1.) That the warhead is aimed at its current position, and doesn't
:> :> :incorerate a "lead" factor of where it's going to be in a half hour's time.
:> :> :
:> :>
:> :> Which assumes there is no early warning time and that the CVBG stays
:> :> 'straight and stupid', maintaining SOA.
:> :>
:> :
:> :Yeah, but you've got to pick up the deorbit burn to alert the carrier
:> :group about what's coming.
:> :
:>
:> And you think nobody would be watching? That's really quite funny!
:>
:
:Oh, of course someone would be watching if this system was ever
:deployed...how fast can you get their info back to the fleet and let the
:act on it after it goes through the channels from detection, to
:confirmation, to action?
:I stated that I thought it would be five minutes.
:Screw that, let's make it instantaneously.
:
Which is approximately what it would be in actuality.
:
:Your carrier group is moving along at 40 knots... in five minutes you
:are going to cover 1/12 of that distance, or to put it another way, you
:have a advantage of an extra 3.3 miles between you and the impact point;
:assuming of course that you can somehow turn the whole fleet around in
:zero time and get it going in the reverse direction.
:
Never been to sea, have you? The amount of time it takes to turn "the
whole fleet around" is just pretty damned short.
:
:This is worthless in regards to a RV that can modify its course on the
:way down; any maneuvers the naval fleet can accomplish given the warning
:of the RV descent and its limited speed are going to ineffectual against
:a maneuvering RV that either incorporates organic homing or descent
:updates from a RORSAT.
:
Neither of the things you propose above are easy problems.
:> :
:> :And that deorbit burn is going to occur around 1/3 of the way around the
:
Oh, nonsense! You're living in fantasyland if you think there's have
been hundreds of these things.
:> What if it does? By the time you can start shedding things you're
:> relatively 'low and slow', as I already mentioned.
:>
:> :
:> :In fact, wouldn't the radar be able to go _clean through_ the
:> :non-metallic RCC nosecap?
:> :
:>
:> It could presumably be designed that way, but it'd be difficult to
:> both do thermal protection AND have a radar antenna sitting behind it.
:>
:
:It's a dielectric; the radar won't even see it.
:
Never been done. You're assuming that your TPS can be
radar-transparent.
--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn
Len Lekx
wrote:
>What if the RCC nosecap separates after reentry to reveal a radar antenna?
>In fact, wouldn't the radar be able to go _clean through_ the
>non-metallic RCC nosecap?
Radio signals have problems with carbon materials - carbon-fiber
aircraft have to have their radio antennas *outside* the hull, because
the carbon absorbs the energy.
Jeff Findley
"Reunite Gondwanaland (Mary Shafer)" <reunite....@gmail.com> wrote in
message news:pptoj49ojietrpndn...@4ax.com...
> Surely I'm not the only one who knows such basic aerodynamics and
> history here. I thought everyone knew about trim alpha, just as
> everyone knows about real aircraft having more drag than predicted.
>
> Mary "Not even an aerodynamicist"
You're surely one of the few here who has had routine exposure to
aerodynamicists. :-)
I'm not an aerodynamicist either, but I had to take a class or two to get my
aerospace engineering degree and while I think I understand what you're
saying, my memory on this subject is still a little foggy. ;-)
Jeff
--
beb - To paraphrase Stephen Colbert, reality has an anti-Ares I bias.
Jorge R. Frank
news:XZqdndIC0qadOKHU...@giganews.com:
Following up on my own post:
My memory is correct, at least for the last ten years. There have been
*no* flights, starting with STS-95 in 1998 (data for flights prior to
STS-95, and inexplicably, STS-106, are not available electronically),
that have required *any* kind of forward ballast, either "hard" fuselage
ballast or FRCS propellant bookkept as ballast to protect certain abort
cases. On most flights the FRCS was not even loaded full.
ALL required ballast in the last ten years has either been aft fuselage
hard ballast, or ARCS/OMS propellant bookkept as "fluid ballast". Given
the diversity of flights covered by this period, I am confident in
stating that forward ballast has *never* been required for *any* shuttle
flight, although the capability to carry forward ballast exists if it
were ever to be needed. Thus I consider the statements in Bell's article
to be debunked.
This also reinforces the arguments against retrofitting escape capsules
into the orbiters - the mass of the capsules would not be offsetting the
mass of forward ballast, because there was never any forward ballast to
offload.
Relevant excerpts from the level A requirements below:
92
THE FOLLOWING CASES REQUIRE BALLAST FOR X-CG VIOLATIONS: CONTINGENCY
RETURN PMA - 184 LBM OMS BALLAST.
93
NO BALLAST IS REQUIRED FOR ANY CASE.
95
THE FOLLOWING CASES REFLECT PROPELLANT BALLAST TO PROTECT A 0.5" X-CG
MARGIN.
AOA REQUIRES 1972 LBM ARCS BALLAST
FLIGHT DAY 2 REQUIRES 1318 LBM ARCS BALLAST
NOMINAL REQUIRES 60 LBM OMS BALLAST
NO-DEPLOY SPARTAN AND IEH REQUIRES 6 LBM OMS BALLAST
NO-RETRIEVE SPARTAN REQUIRES 92 LBM OMS BALLAST
FOR DF63 USE ONLY: THE FOLLOWING CASES REFLECT PROPELLANT BALLAST TO
PROTECT A 0.0"X-CG MARGIN.
AOA REQUIRES 1526 LBM ARCS BALLAST
FLIGHT DAY 2 REQUIRES 880 LBM ARCS BALLAST
96
THE FOLLOWING CASES REQUIRE BALLAST
NO-DEPLOY FWD CASE REQUIRES 252 LBM OMS BALLAST
AOA CASE REQUIRES 1062 LBM ARCS BALLAST
FD2 CASE REQUIRES 518 LBM ARCS BALLAST
REV3 REQUIRES 322 LBM ARCS BALLAST
97
AOA CASE REQUIRES 326 LBM OF ARCS BALLAST.
NO HARD BALLAST REQUIREMENT
98
NO BALLAST REQUIREMENT FOR ANY CASE.
99
1450 LBM AFT FUSELAGE HARD BALLAST FOR ALL CASES
1962 LBM ARCS PROPELLANT BALLAST FOR AOA CASE
100
ALL MASS PROPERTIES REFLECT 1600 LBM AFT FUSELAGE HARD BALLAST.
THE FOLLOWING CASES REQUIRE PROPELLANT BALLAST:
1944 LBM ARCS FOR THE AOA CASE
1204 LBM ARRC FOR THE REV 3 CASE
534 LBM ARCS FOR THE REV 7 CASE
1408 LBM ARCS FOR FLIGHT DAY 2
ADDITIONALLY, THE DEPLOY ONLY MPLM CASE REQUIRES A TOTAL OF 1792 LBM OMS;
HOWEVER, DOUBLE BOOKKEEPING THE CONTINGENCY PAYLOAD RETURN AND THE
DELTA OMS USAGE BETWEEN THE REQUIRED NOMINAL MISSION USAGE AND THE
LESSER DEPLOY ONLY MPLM PROPELLANT REQUIREMENT LEAVES A BALLAST
REQUIREMENT OF 1185 LBM.
101
THE FOLLOWING CASES REFLECT PROPELLANT BALLAST TO PROTECT FOR THE
0.5" X-CG MARGIN:
NO DEPLOY FORWARD (NO EVA SCENARIO) REQUIRES 536 LBM OF OMS BALLAST
AOA REQUIRES 1062 LBM OF ARCS BALLAST
FLIGHT DAY 2 REQUIRES 508 LBM OF ARCS BALLAST
102
ALL CASES REFLECT 1060 LBM AFT FUSELAGE BALLAST.
PROPELLANT BALLAST WAS NOT REQUIRED FOR ANY OF THE CASES.
103
BALLAST WAS NOT REQUIRED FOR ANY CASE.
104
ALL MASS PROPERTIES REFLECT 2237 LBM AFT FUSELAGE HARD BALLAST
FOR THE NO DEPLOY SLDP AND MIDDECK CASE 2668 LBM OMS PROPELLANT WAS
BUDGETED
FOR BALLAST
105
ALL CASES REFLECT 1606 LBM AFT FUSELAGE HARD BALLAST.
PROPELLANT BALLAST WAS NOT REQUIRED.
107
ALL MASS PROPERTIES REFLECT A 215 LBM AFT FUSELAGE BALLAST (ORIGINALLY,
TDDP
CALLED OUT FOR 760 LBM AFT FUSELAGE BALLAST)
THE NOMINAL CASE REQUIRES 531 LBM OF FLUID BALLAST THE AOA CASE REQUIRES
44 LBM OF ARCS BALLAST
EDO DEPLETION REQUIRES AN ADDITIONAL 1125 OF OMS PROPELLANT BALLAST. THIS
REQUIREMENT IS COVERED BY THREE SOURCES: 633 LBM OF OMS FROM PROPELLANT
BUYBACKS IN THE NOMINAL PROPELLANT BUDGET; 304 LBM ARCS AND 107 LBM OMS
FROM THE 48 HOUR EXTENSION PROPELLENT ALLOCATION; AND 128 LBM OMS FROM A
LINE ITEM IN THE DISPERSION CHART.
108
ALL MASS PROPERTIES REFLECT 128 LBM OF AFT FUSELAGE BALLAST
NO FLUID BALLAST IS REQUIRED
109
NO BALLAST REQUIRED
110
ALL MASS PROPERTIES REFLECT 1810 LBM AFT FUSELAGE HARD BALLAST.
THE FOLLOWING CASES REQUIRE PROPELLANT BALLAST:
1826 LBM ARCS FOR THE AOA CASE
1089 LBM ARCS FOR THE REV 3 CASE
419 LBM ARCS FOR THE REV 7 CASE
1290 LBM ARCS FOR THE FD2 CASE
284 LBM OMS FOR THE NO DEPLOY ALL CASE
111
820 LBM OF AFT FUSELAGE BALLAST IS LOADED
112
2237 LBM OF AFT FUSELAGE BALLAST IS LOADED
THE FOLLOWING CASES REQUIRE FLUID BALLAST:
- NO DEPLOY S1 REQUIRES 146 LBM OMS PROPELLANT
- AOA REQUIRES 1472 LBM OF ARCS PROPELLANT
- REV 3 REQUIRES 732 LBM OF ARCS PROPELLANT
- REV 7 REQUIRES 62 LBM OF ARCS PROPELLANT
- FD2 REQUIRES 936 LBM OF ARCS PROPELLANT
113
ALL MASS PROPERTIES REFLECT 2400 LBM AFT FUSELAGE HARD BALLAST AND FULL
APU
THE FOLLOWING CASES REQUIRE PROPELLANT BALLAST:
- 2000 LBM ARCS AND 100 LBM OMS FOR THE AOA CASE
- 1260 LBM ARCS AND 100 LBM OMS FOR THE REV 3 CASE
- 590 LBM ARCS AND 100 LBM OMS FOR THE REV 7 CASE
- 954 LBM ARCS AND 84 LBM OMS FOR THE FD2 CASE
- 376 LBM OMS FOR THE NO DEPLOY ALL CASE
- 376 LBM OMS FOR THE FAILED DOCK CASE
114
AFT FUSELAGE BALLAST IS 107 LBM (CONTAINERS ONLY).
THE WORST CASE FWD CASE REQUIRES 52 LBM OMS BALLAST.
115
AFT FUSELAGE BALLAST IS 102 LBM (CONTAINERS ONLY).
NO FLUID BALLAST REQUIRED FOR ANY CASE.
116
AFT FUSELAGE BALLAST IS 2237 LBM (MAXIMUM).
BALLAST REQUIREMENTS:
- NOMINAL REQUIRES 1608 LBM OMS;
- NO DPLY NO RTRV CASE REQUIRES 1042 LBM OMS;
- PLS REQUIRES 277 LBM AFT RCS AND 2016 LBM OMS;
- FD2 REQUIRES 2332 LBM AFT RCS;
- AOA REQUIRES 2907 LBM AFT RCS AND 934 LBM OMS;
- ATO REV3 REQUIRES 2167 LBM AFT RCS AND 934 LBM OMS; AND
- ATO REV7 REQUIRES 1497 LBM AFT RCS AND 934 LBM OMS.
117
102 LB M AFT FUSELAGE BALLAST IS INCLUDED IN THE ORBITER MASS (BOX ONLY).
NO FLUID BALLAST WAS REQUIRED.
118
AFT FUSELAGE BALLAST IS 2697 LBM.
THE FOLLOWING CASES REQUIRED BALLAST:
NOMINAL REQUIRES 64 LBM ARCS AND 3084 LBM OMS BALLAST
NO DOCK PLS REQUIRES 422 LBM ARCS AND 1422 LBM OMS BALLAST
WORST CASE FWD REQUIRES 368 LBM ARCS AND 3238 LBM OMS BALLAST
WORST CASE AFT REQUIRES 363 LBM ARCS AND 160 LBM OMS BALLAST
AOA REQUIRES 2120 LBM ARCS BALLAST
REV 3 REQUIRES 1380 LBM ARCS BALLAST
REV 7 REQUIRES 710 LBM ARCS BALLAST
FD2 REQUIRES 1763 LBM ARCS BALLAST
119
Aft fuselage ballast is 104 lbm.
The following cases require ballast in order to push the CG back for the
YCG to be within constraints:
NO DOCK PLS requires 354 lbm ARCS
AOA requires 345 lbm ARCS
120
AFT FUSELAGE BALLAST IS 102 LBM (CONTAINERS ONLY).
NO FLUID BALLAST REQUIRED FOR ANY CASE.
121
AFT FUSELAGE BALLAST IS 102 LBM (CONTAINERS ONLY).
THE FOLLOWING CASES REQUIRED FLUID BALLAST:
- WORST-CASE FWD REQUIRED 433 LBM ARCS, 400 LBM OMS
- AOA REQUIRED 586 LBM ARCS
- FD2 REQUIRED 44 LBM ARCS
122
Aft fuselage ballast is 102 lbm.
5) The following cases require ballast:
NOMINAL requires 676 lbm OMS
NO DPLY SOLAR & NTA/NO RTV NTA requires 309 lbm ARCS & 920 lbm OMS
NO DOCK PLS/DPLY COL MOD (FOR FDM USE ONLY) requires 678 lbm ARCS & 770
lbm OMS
123
Aft fuselage ballast is 1129 lbm.
The following case requires ballast:
FAIL ALL BUT JEM & SPL requires 300 lbm ARCS & 160 lbm OMS
124
Aft fuselage ballast is 2260 lbm.
No fluid ballast is required.
125
Aft fuselage ballast is 1752 lbm.
The following cases require ballast:
FD2 requires 1247 lbm ARCS
AOA requires 1660 lbm ARCS
ATO REV3 requires 920 lbm ARCS
ATO REV7 requires 250 lbm ARCS
126
Aft fuselage ballast is 126 lbm.
No fluid ballast is required.
127
Aft fuselage ballast is 2714 lbm.
The following cases require ballast:
NO DPLY JEM & PICO/RTRV NONE requires 57 lbm ARCS & 1114 lbm OMS
128
Aft fuselage ballast is 102 lbm.
No fluid ballast is required.
129
Aft fuselage ballast is 854 lbm.
The following cases require ballast:
AOA requires 27 lbm ARCS
400
Aft fuselage ballast is 126 lbm.
No fluid ballast is required.
401
Aft fuselage ballast is 126 lbm.
No fluid ballast is required.
OM
<jrf...@ibm-pc.borg> wrote:
>Thus I consider the statements in Bell's article
>to be debunked.
...Not that he'd ever admit he was wrong publically. Bell is one of
those idiots like that "Mathemaidiot" who used to troll around here a
few years back, one who's too chickenshit to post any sort of
retraction when he's clearly wrong, much less provide a valid e-mail
addy from which to at least discuss the errors of his ways.
...It should be required that any online news service provide a
discussion/feedback forum for each article it publishes, so that
bullshit artists like Jeff Bell can be very quickly ferreted out.
OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[
Monte Davis
>"Ballast is an inelegant solution, to be sure, but it is simple and
>cheap..."
>
>I would like to see documentation that settles the issue of whether
>the 'accomodation' of ballast resulted from design error or design
>flexibility.
Whatever. *You* be the one to tell fifty years of rocket, satellite
and spacecraft designers who have focused maniacally on mass reduction
and maximum strength/weight that a ton or more of non-functional mass
represents "flexibility."
Again, I did not use the word "error." The need for the ballast could
not have been foreseen; by the time it became apparent, it was too
late to redesign/redistribute other orbiter structures or equipment to
do the same balancing job. But that hardly justifies designating a bug
as a feature.
Fred J. McCall
:
:... one who's too chickenshit to post any sort of
:retraction when he's clearly wrong, much less provide a valid e-mail
:addy from which to at least discuss the errors of his ways.
So om@all_trolls_must_DIE.com is your real email address, is it? Or
are you just another chickenshit?
--
You are
What you do
When it counts.
Pat Flannery
Fred J. McCall wrote:
> That weight increase also doesn't sound correct, looking at weights of
> current US nuclear weapons. For example, two current weapons are the
> B-83 and the W-87. The B-83 is variable yield up to 1.2MT and weighs
> around 2400 pounds. The W-87 is 300KT and weighs less than 600
> pounds. These are two weapons that are modern and recently
> manufactured as such things go. They would make it appear that
> getting from hundreds of kilotons to megatons is a 400% increase in
> weight, not the 50% you claim above.
>
W-87 is a warhead...B-83 is a complete bomb, including a finned casing
and large parachute.
Both are thermonuclear devices using a primary and a secondary stage (2
in the B-83?).
If you want a big yield at low weight, go for a W-59 with a one megaton
yield and weighing 553 pounds:
http://hypertextbook.com/physics/modern/weapons/yield-to-weight.txt
Pat
Fred J. McCall
:
:
:
So why doesn't Russia use multiple warheads or something bigger than
550 KT on Topol-M, if it's so easy?
Throw weight of Topol-M is around 1,000 kg.
SEN...@argo.rhein-neckar.de
No Jorge. Bell (and Mary) wrote about the fixed ballast of the shuttle.
You presented the case data from the variable ballast sheet. This are two
different things. On the variable ballast sheet you never see the fixed
ballast because its considered part of the fuselage structure.
The fixed ballast is adjusted to allow missions with no or minor variable
ballast like you see for #93, #98 or #103 below. For the Shuttle there may
be some further constraints relating to (a) total mass and (b) rotational
inertia. The automatic control may need a+b in some range to keep the
re-entry and landing flight regime in a well known data corridor. So it
may not only a matter of CG. Thats why we see below sometimes "hard
ballast" in the aft.
## CrossPoint v3.12d R ##
Jorge R. Frank
> Although the ballast may be there because other equipment, installed
> further aft, turned out heavier than expected.
>> Is it true that the orbiters carry that much nose ballast?
>
> The amount may well vary depending on payload. That's probably a
> maximum. I wonder why they use lead instead of something denser, like
> depleted uranium.
> The ballast may not be removable if you want the trim alpha the
> vehicle was designed for.
Mary,
Could you clarify your comments a bit? Do you mean to refer to the space
shuttle specifically or aircraft in general?
I've checked with a senior PROP flight controller (whose group is
responsible for maintaining orbiter CG in flight, and does the preflight
analysis to determine if and where ballast should be used), and with Dennis
Jenkins (who checked the mass properties reports), and both are fairly
certain we've never used forward ballast on any shuttle mission. I'm 100%
certain we've never used forward ballast on any mission in the last ten
years. The PROP flight controller informed me about the use of forward
ballast for CG control on SCA ferry flights, and Dennis has also informed
me that forward ballast was used on OV-101 for the ALT flights. But that's
pretty much it.
Monte Davis
>first you clipped the name of the original poster...
Me. I wrote "triplet of 200 KT warheads" as a representative ICBM/SLBM
load, but the details don't matter.
What matters, as far as I'm concenred, is that more than 25 years ago,
as a writer for a national science magazine, I presented a spokesman
for the CNO with a scenario based entirely on conservative estimates
-- published and unchallenged -- for
1) our (and the USSR's) satellite/sub/etc capabilities for spotting
tracking surface ships
2) our (and the USSR's) time requirements for aiming/launching/flight
and for alerts of same
3) our (and the USSR's) claimed CEP
4) our (and the USSR's) claimed top speed for carriers
5) blast overpressure required to tip ships on their beam, stove in
hull plates, or rip off superstructure (never mind details like
sweeping aircraft off flight decks) -- cf. ABLE & BAKER, 1946
The question I posed was "Never mind the Tom Clancy waves of anti-ship
missiles. Never mind the attack subs shadowing surface combatants, the
attack subs shadowing boomers *and* attack subs, etc. Given these
figures, what reason is there to believe that ICBMs alone couldn't
deal with most carrier groups within an hour?"
What I got was hemming, hawing, handwaving and pregnant silences.
I suppose it could be that since then, warheads have become much less
accurate, capital ships have become much faster and tougher -- or that
terminal guidance would be jammed by flying pigs. Wouldn't it be
pretty to think so?
-Monte Davis
Monte Davis
since the ICBM deployments of the 1960s and 1970s, the zoomy fantasies
about FOBS, weaponized Shuttle/Buran, and hypersonic bombers have
remained fantasies for the good and sufficient reason that they
*simply don't yield enough advantage over what ICBMs and SLBMs can
already do* to be worth it.
-Monte Davis
Fred J. McCall
:
What really matters, so far as I'm concerned, is that you couldn't be
given an answer because the person you asked knows the real
(classified) facts of things and you weren't bright enough to
recognize that. Since he's not supposed to lie to you outright, what
did you expect?
Just as a hint, lots of people routinely do the same thing on Usenet.
Rather than base an argument or position on personally known
(classified) information, they will do so based on what is currently
published EVEN IF THEY KNOW IT IS WRONG. Unlike an official
spokesman, they are allowed to not tell you the truth...
Let me give you a hint as to what's wrong with your question. Find a
number for how much overpressure something like an aircraft carrier
can stand (good luck with that one - you'll probably just have to
arbitrarily pick something). Compute how far the carrier can move in
the amount of warning time it has (good luck finding that - you'll
probably just have to pick some amount of time and some top speed).
Given the preceding, calculate how many weapons you have to lay down
in a grid within that circle the carrier MIGHT be in. Keep in mind
the (in)accuracy of the weapons you're firing, as that will
necessitate putting them closer together than your original
calculation says you need.
Once you've done all that, calculate the total cost of all the
warheads and delivery systems required in order to try to kill a
carrier with ICBMs. See if it meets the threshold to be a worthwhile
way to try to kill carriers.
[Now multiply by a dozen to see what it costs to get all the
carriers.]
Pat Flannery
Monte Davis wrote:
Sorry about the unintentional clip BTW :-[
> The question I posed was "Never mind the Tom Clancy waves of anti-ship
> missiles. Never mind the attack subs shadowing surface combatants, the
> attack subs shadowing boomers *and* attack subs, etc. Given these
> figures, what reason is there to believe that ICBMs alone couldn't
> deal with most carrier groups within an hour?"
>
That would require retargeting them to hit a moving target.
I assume that all targeting info is already preloaded into the command
centers as to target options to attack with latitude and longitude
already worked out and ready to be entered into the ICBM guidance system
with just a few simple button pushes.
But that won't apply to something in the middle of the ocean, so it
might take some time to work out a targeting solution on it and transmit
it to the missile command center.
Actually, a SLBM might be better to do this with, as it needs to be able
to plot a new trajectory to its target as the sub moves.
Even then, Derek Lyons (who served on a boomer) stated that this wasn't
something you can do in a hurry, and IIRC it took around 15 minutes or
more to get the SLBMs ready to go once a go decision was reached and the
targets selected, because you had to spin up and align the gyros.
They might have improved that by now (laser ring gyros).
I once read that the Soviets did indeed give their ICBMs the ability to
hit targets at sea, as they considered ICBMs to be something along the
line of super artillery.
> What I got was hemming, hawing, handwaving and pregnant silences.
>
> I suppose it could be that since then, warheads have become much less
> accurate, capital ships have become much faster and tougher -- or that
> terminal guidance would be jammed by flying pigs. Wouldn't it be
> pretty to think so?
>
Looking at the BOR type lifting body warheads coming out of the Buran
bomber: http://www.buran.fr/bourane-buran/img/bor_bur.jpg
....shows a problem...although they do increase cross range to carrier
task forces that can be hit, if they glide all the way down to the
target they are going to be sitting ducks for interception by a Standard
Missile.
One thing you could attack with these would be submarines.
That may figure into the discovery that both we and the Soviets made
about how the underwater terrain of the ocean is mirrored on its surface
by subtle shifts in its height due to varying gravity forces through the
water that are transmitted to the surface*, and how a sub that is
underway will create a hump and dip in the water behind it that a RORSAT
can detect. There is also the thermal upwelling that would be detectable
via IR as the sub's reactor-generated steam is cooled by circulating
seawater through the steam re-condensation circuit that would work for
submarines at rest also.
You move and the radar finds you; you sit still and the IR can catch you.
It's stuff like that that makes one realize why the Soviets were keen on
hiding their Typhoons under the arctic icecap where radar and heat
sensors would bounce off the ice above them.
* That's literally a mirror image BTW... underwater canyons show up as
bumps on the surface, and mountains as dips.
That was a major US Navy secret until the Soviets mentioned it in the
open press around a decade back.
One thing that neither side has yet confirmed is that you can use a
"Mass Detector" to navigate our subs through shallow waters without
active sonar emissions - this got mentioned in the book "The Hunt For
Red October" but the Navy told them to take it out of the movie version
if they wanted their help in making it.
This was somewhat pointless, as a prototype of the system was carried
aboard the Submarine "Triton" when it circled the Earth way back in
1960, and was described in her captain's book about the voyage, "Around
The World Submerged".
As to what the secret system is that allows them to track American
submarines without the use of even passive sonar is a interesting question.
I suspect they are using some sort of a technology that allows them to
detect a sub the way a shark can detect its prey at great distance by
picking up the electrical emissions of its muscles moving.
That's so sensitive that a shark could pick up the electrical field
generated by sticking two wires from a 9 volt battery's terminals into
the water several miles apart.
Their system probably picks up electrical effects of the the machinery
working inside the sub as it passes into the water through its hull.
Pat
Pat Flannery
Monte Davis wrote:
> and hypersonic bombers have
> remained fantasies for the good and sufficient reason that they
> *simply don't yield enough advantage over what ICBMs and SLBMs can
> already do* to be worth it.
>
>
>
Except, of course, for FALCON:
http://www.defensetech.org/archives/002868.html
My favorite though is still a toss-up between "SUSTAIN" - "Let's drop
twelve Marines on the enemy from space!":
http://www.defensetech.org/archives/001815.html
and "WALRUS" - "Let's take 500 Marines and all their equipment into
enemy territory on a giant dirigible!":
http://www.defenseindustrydaily.com/walrus-hunted-to-extinction-by-congress-darpa-02102/
Not since the Reagan administration has so much money been thrown at so
goofy and pointless military programs.
It's still not too late to get those Iowa class battleships back into
action with nuclear reactors, laser cannons, rocket engines, and
hydrofoils added to the basic ship.
I almost forgot the rocket-boosted, GPS homing, thermonuclear warheaded
shells for the 16" guns.
Those go without saying.
We'll show those damn Somali pirates a thing or two!
They'll come out in a converted fishing trawler, and run into something
that would scare the radioactive crap out of Godzilla! :-D
Pat
Pat Flannery
Fred J. McCall wrote:
> Let me give you a hint as to what's wrong with your question. Find a
> number for how much overpressure something like an aircraft carrier
> can stand (good luck with that one - you'll probably just have to
> arbitrarily pick something). Compute how far the carrier can move in
> the amount of warning time it has (good luck finding that - you'll
> probably just have to pick some amount of time and some top speed).
>
The last one is pretty easy to figure out:
http://www.navweaps.com/index_tech/tech-028.htm
Since even adding a few knots to a carrier's maximum speed is going to
take a lot of extra horsepower, you can figure out the max speed within
a few knots fairly easily.
Also, there is the "convoy rule" in effect here; the speed of the
carrier attack group is based on the speed of the slowest ship in it.
If the carrier and its fast escort vessels decide to run away from all
of the support vessels to escape a nuclear attack, they probably can
indeed move out at over 30 knots.
But again, what if you target them with a "lead" in your impact point?
Then they need to determine they are under attack ASAP and immediately
reverse course to escape it. And the enemy might figure out that they
will do that, and put a second warhead on their estimated position if
they do reverse course.
For airbursts, the carrier is probably pretty survivable; the aircraft
on deck will probably be rendered unflyable if not swept clean off of
the deck by the blast effects and radar gear and such on the island will
probable be rendered at least temporarily inoperable. But the water
spray system is designed to wash fallout off of the ship, so it at least
will be able to stay afloat and probably operate any aircraft that were
in the hanger deck when the detonation occurred.
The effects of a subsurface detonation in proximity to the carrier are a
lot more severe; not only does the hull get a walloping big shockwave
sent through it, but the ship may get drenched with highly radioactive
water thrown into the air by the subsurface blast, like the target ships
at the Baker test were.
So can you drop a nuclear warhead into the water at supersonic speeds
and have it detonate?
Yes, you indeed can; the SUBROC warhead would enter the water over its
target supersonically.
Even a airburst close to the sea's surface of a large yield nuclear
weapon is going to transmit a lot of its shockwave into the water and
blow radioactive water all over the place in the form of a giant cloud
of radioactive steam.
> Given the preceding, calculate how many weapons you have to lay down
> in a grid within that circle the carrier MIGHT be in. Keep in mind
> the (in)accuracy of the weapons you're firing, as that will
> necessitate putting them closer together than your original
> calculation says you need.
>
> Once you've done all that, calculate the total cost of all the
> warheads and delivery systems required in order to try to kill a
> carrier with ICBMs. See if it meets the threshold to be a worthwhile
> way to try to kill carriers.
>
This of course relies on the fact that the warhead can't self-home
after reentry. From around fifty miles up it will be able to see a lot
of the sea's surface under it easily including any carrier force trying
to escape it, and like our Pershing II, it might be able to use a
nose-mounted radar to home on its target.
You want a great radar target?
How about a 4.5 acre steel flight deck of a Nimitz class carrier
pointing straight up at the sky as you descend on it?
Screw the lifting body concept and subsurface detonation, even a 10 kT
warhead coming down on a ballistic trajectory that will physically hit
the carrier while going at multiple Mach numbers on its way down (to
evade intercept by a Standard missile) will blow the carrier into
superheated scrap metal on impact.
And this photo of incoming MX ICBM warheads show that they hit fast
enough to keep glowing all the way down as their RV's ablate:
http://tbn0.google.com/hosted/images/c?q=149a16d0c0ebcd4c_landing
Fred J. McCall
:
:Fred J. McCall wrote:
:> Let me give you a hint as to what's wrong with your question. Find a
:> number for how much overpressure something like an aircraft carrier
:> can stand (good luck with that one - you'll probably just have to
:> arbitrarily pick something). Compute how far the carrier can move in
:> the amount of warning time it has (good luck finding that - you'll
:> probably just have to pick some amount of time and some top speed).
:>
:
:The last one is pretty easy to figure out:
:http://www.navweaps.com/index_tech/tech-028.htm
:Since even adding a few knots to a carrier's maximum speed is going to
:take a lot of extra horsepower, you can figure out the max speed within
:a few knots fairly easily.
:Also, there is the "convoy rule" in effect here; the speed of the
:carrier attack group is based on the speed of the slowest ship in it.
:If the carrier and its fast escort vessels decide to run away from all
:of the support vessels to escape a nuclear attack, they probably can
:indeed move out at over 30 knots.
:But again, what if you target them with a "lead" in your impact point?
:Then they need to determine they are under attack ASAP and immediately
:reverse course to escape it. And the enemy might figure out that they
:will do that, and put a second warhead on their estimated position if
:they do reverse course.
Think about it. Why would they precisely reverse course? What would
most likely happen is they'd scatter in all directions and not stay
together at all (nor would they precisely reverse course, which is a
fairly stupid tactic, come to that).
:
:For airbursts, the carrier is probably pretty survivable; the aircraft
:on deck will probably be rendered unflyable if not swept clean off of
:the deck by the blast effects and radar gear and such on the island will
:probable be rendered at least temporarily inoperable. But the water
:spray system is designed to wash fallout off of the ship, so it at least
:will be able to stay afloat and probably operate any aircraft that were
:in the hanger deck when the detonation occurred.
:
Which would probably be most of them. There probably wouldn't be more
than a handful of aircraft on deck, if that.
:
:The effects of a subsurface detonation in proximity to the carrier are a
:lot more severe; not only does the hull get a walloping big shockwave
:sent through it, but the ship may get drenched with highly radioactive
:water thrown into the air by the subsurface blast, like the target ships
:at the Baker test were.
:
The washdown system is designed to handle water from the base surge.
You might be surprised at how well a ship can resist damage from
shockwaves in the water. Then again, you might not. You won't find
anything in public about it other than speculation.
:
:So can you drop a nuclear warhead into the water at supersonic speeds
:and have it detonate?
:Yes, you indeed can; the SUBROC warhead would enter the water over its
:target supersonically.
:
Do you have a cite for that? SUBROC flew supersonic in air, but I
find nothing to indicate that it remained supersonic until it hit the
water. In point of fact, it blew the engine off and flew ballistic,
so I would expect it to slow back down before it hit the water.
:
:Even a airburst close to the sea's surface of a large yield nuclear
:weapon is going to transmit a lot of its shockwave into the water and
:blow radioactive water all over the place in the form of a giant cloud
:of radioactive steam.
:
In general this is a "don't care" for USN ships. It's what the water
washdown system is for.
:> Given the preceding, calculate how many weapons you have to lay down
:> in a grid within that circle the carrier MIGHT be in. Keep in mind
:> the (in)accuracy of the weapons you're firing, as that will
:> necessitate putting them closer together than your original
:> calculation says you need.
:>
:> Once you've done all that, calculate the total cost of all the
:> warheads and delivery systems required in order to try to kill a
:> carrier with ICBMs. See if it meets the threshold to be a worthwhile
:> way to try to kill carriers.
:>
:
: This of course relies on the fact that the warhead can't self-home
:after reentry. From around fifty miles up it will be able to see a lot
:of the sea's surface under it easily including any carrier force trying
:to escape it, and like our Pershing II, it might be able to use a
:nose-mounted radar to home on its target.
:
Pershing II attacked STATIONARY targets with lots of well-mapped radar
features to navigate by. You're not talking about the same thing at
all here.
:
:You want a great radar target?
:How about a 4.5 acre steel flight deck of a Nimitz class carrier
:pointing straight up at the sky as you descend on it?
:
Sea surface clutter matters. It's not as easy as you maintain.
:
:Screw the lifting body concept and subsurface detonation, even a 10 kT
:warhead coming down on a ballistic trajectory that will physically hit
:the carrier while going at multiple Mach numbers on its way down (to
:evade intercept by a Standard missile) will blow the carrier into
:superheated scrap metal on impact.
:
High speed won't "evade intercept by a Standard missile" and I wish
you luck making your system work as you describe it.
:
:And this photo of incoming MX ICBM warheads show that they hit fast
:enough to keep glowing all the way down as their RV's ablate:
:http://tbn0.google.com/hosted/images/c?q=149a16d0c0ebcd4c_landing
:
Yes, they do, and that means you can't see out with your radar sensor.
You can't have it both ways. Either you slow down or you're coming in
blind.
Pat Flannery
Fred J. McCall wrote:
>
> Think about it. Why would they precisely reverse course? What would
> most likely happen is they'd scatter in all directions and not stay
> together at all (nor would they precisely reverse course, which is a
> fairly stupid tactic, come to that).
>
Assuming the concept is to get as far away from the blast point as
possible then the way to do it is to reverse course; any course other
than that is going to leave you closer to the detonation point.
> :For airbursts, the carrier is probably pretty survivable; the aircraft
> :on deck will probably be rendered unflyable if not swept clean off of
> :the deck by the blast effects and radar gear and such on the island will
> :probable be rendered at least temporarily inoperable. But the water
> :spray system is designed to wash fallout off of the ship, so it at least
> :will be able to stay afloat and probably operate any aircraft that were
> :in the hanger deck when the detonation occurred.
> :
>
> Which would probably be most of them. There probably wouldn't be more
> than a handful of aircraft on deck, if that.
>
Are you sure about that? If this happens in that timeframe then you
might well be a target for Badger, Blinder, or Backfire attacks via AS-4
"Kitchen" or AS-6 "Kingfish" cruise missiles, so you are going to want
your Hawkeyes and Tomcats up to intercept any bombers that are in the
vicinity while they are still out of missile attack range.
> Do you have a cite for that? SUBROC flew supersonic in air, but I
> find nothing to indicate that it remained supersonic until it hit the
> water. In point of fact, it blew the engine off and flew ballistic,
> so I would expect it to slow back down before it hit the water.
>
"Rockets and Missiles" by Bill Gunston, 1979, page 259:
"Clear of the water, the SUBROC quickly accelerates to supersonic speed,
whilst continuously guided by the SD-510 inertial system and jetevator
nozzles. At the required cutoff speed to give the correct range the
propulsion is arrested; in 60 milliseconds explosive bolts separate the
warhead, forward-facing ports reverse the thrust of the rocket motor,
and the inertial system begins to control the trajectory of the warhead
by means of small aerodynamic fins. Unlike ballistic missiles, the
guidance continues on the downward trajectory, which again posed new
problems. Yet another new hurdle to be overcome was reentry to the water
at supersonic speed, still under guidance and without affecting the
complex safe/arm system for the nuclear warhead. The device sinks to
optimum depth and is there triggered, with lethal radius of 3-5 miles
(5-8 km)."
> :
> :Even a airburst close to the sea's surface of a large yield nuclear
> :weapon is going to transmit a lot of its shockwave into the water and
> :blow radioactive water all over the place in the form of a giant cloud
> :of radioactive steam.
> :
>
> In general this is a "don't care" for USN ships. It's what the water
> washdown system is for.
>
> :> Given the preceding, calculate how many weapons you have to lay down
> :> in a grid within that circle the carrier MIGHT be in. Keep in mind
> :> the (in)accuracy of the weapons you're firing, as that will
> :> necessitate putting them closer together than your original
> :> calculation says you need.
> :>
> :> Once you've done all that, calculate the total cost of all the
> :> warheads and delivery systems required in order to try to kill a
> :> carrier with ICBMs. See if it meets the threshold to be a worthwhile
> :> way to try to kill carriers.
> :>
> :
> : This of course relies on the fact that the warhead can't self-home
> :after reentry. From around fifty miles up it will be able to see a lot
> :of the sea's surface under it easily including any carrier force trying
> :to escape it, and like our Pershing II, it might be able to use a
> :nose-mounted radar to home on its target.
> :
>
> Pershing II attacked STATIONARY targets with lots of well-mapped radar
> features to navigate by. You're not talking about the same thing at
> all here.
>
No, you are talking about a multi-acre plate of steel facing straight up
in a sea that has a different radar return from the carrier flight deck,
and also has waves changing the radar return from the sea's surface from
second to second.
Just like the way that Doppler radar allows a aircraft's AAM to
differentiate a moving aircraft from non-moving background clutter
caused by the Earth's terrain under it, this radar would look for the
reverse...a solid radar return surrounded by a variable radar return
from the sea's surface. Also, radar frequency selection could easily
differentiate between water and the metal making up the carrier's structure.
Pat
Fred J. McCall
:
:Fred J. McCall wrote:
:>
:> Think about it. Why would they precisely reverse course? What would
:> most likely happen is they'd scatter in all directions and not stay
:> together at all (nor would they precisely reverse course, which is a
:> fairly stupid tactic, come to that).
:>
:Assuming the concept is to get as far away from the blast point as
:possible then the way to do it is to reverse course; any course other
:than that is going to leave you closer to the detonation point.
:
No, because that assumes the guy shooting at you is both stupid and
has weapons that are guaranteed to go exactly where he aims them.
Neither of those tends to be true.
:> :For airbursts, the carrier is probably pretty survivable; the aircraft
:> :on deck will probably be rendered unflyable if not swept clean off of
:> :the deck by the blast effects and radar gear and such on the island will
:> :probable be rendered at least temporarily inoperable. But the water
:> :spray system is designed to wash fallout off of the ship, so it at least
:> :will be able to stay afloat and probably operate any aircraft that were
:> :in the hanger deck when the detonation occurred.
:> :
:>
:> Which would probably be most of them. There probably wouldn't be more
:> than a handful of aircraft on deck, if that.
:>
:
:Are you sure about that? If this happens in that timeframe then you
:might well be a target for Badger, Blinder, or Backfire attacks via AS-4
:"Kitchen" or AS-6 "Kingfish" cruise missiles, so you are going to want
:your Hawkeyes and Tomcats up to intercept any bombers that are in the
:vicinity while they are still out of missile attack range.
:
I'm positive of that. There are no Tomcats anymore and there would be
one Hawkeye airborne. But the issue isn't what's airborne. The issue
is what's on deck that you can't either cat or strike below given
warning of a nuclear strike.
:> Do you have a cite for that? SUBROC flew supersonic in air, but I
:> find nothing to indicate that it remained supersonic until it hit the
:> water. In point of fact, it blew the engine off and flew ballistic,
:> so I would expect it to slow back down before it hit the water.
:>
:
:"Rockets and Missiles" by Bill Gunston, 1979, page 259:
:"Clear of the water, the SUBROC quickly accelerates to supersonic speed,
:whilst continuously guided by the SD-510 inertial system and jetevator
:nozzles. At the required cutoff speed to give the correct range the
:propulsion is arrested; in 60 milliseconds explosive bolts separate the
:warhead, forward-facing ports reverse the thrust of the rocket motor,
:and the inertial system begins to control the trajectory of the warhead
:by means of small aerodynamic fins. Unlike ballistic missiles, the
:guidance continues on the downward trajectory, which again posed new
:problems. Yet another new hurdle to be overcome was reentry to the water
:at supersonic speed, still under guidance and without affecting the
:complex safe/arm system for the nuclear warhead. The device sinks to
:optimum depth and is there triggered, with lethal radius of 3-5 miles
:(5-8 km)."
:
Thanks. I don't know that I'd want to try that at reentry speeds,
though.
:
:> :
:> :Even a airburst close to the sea's surface of a large yield nuclear
:
Except that deck is moving about, as well. These things aren't
buildings, you know.
:
:Just like the way that Doppler radar allows a aircraft's AAM to
:differentiate a moving aircraft from non-moving background clutter
:caused by the Earth's terrain under it, this radar would look for the
:reverse...a solid radar return surrounded by a variable radar return
:from the sea's surface. Also, radar frequency selection could easily
:differentiate between water and the metal making up the carrier's structure.
:
Pat, you should get into my line of work, since you seem to find a lot
of things can be done "easily" that a lot of very smart folks spent a
lot of time and money trying to do.