Author Topic: The Shuttle Centaur  (Read 82912 times)

Offline publiusr

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RE: The Shuttle Centaur
« Reply #20 on: 05/04/2006 05:22 PM »
What is more, the current Cassini Titan probe needed both a good upper stage and gravity assist.

If you want greater outer planet probes, you need a bigger rocket. It would probably take CaLV to do JIMO right, sample return missions from Mars (with margin) and Europa landers. We got away with the Delta II to Mars because that planet did us a favor by being nearby and had an atmosphere to aerobrake and pop a chute in.

You won't do that with Europa. No cheating. You will have to dump speed and burn your way to the surface. By the time you are done you melt and deploy a cryobot about the same size as Spirit or Opp. That looks for smokers.

So you need real heavy lift to orbit Kuiper objects, to land on Jovian moons, or to return Martian samples.

Either that or these Rube Goldberg schemes people come up with who fall all over themselves to keep from admitting a need for greater lift.

Offline Jim

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RE: The Shuttle Centaur
« Reply #21 on: 05/04/2006 05:54 PM »
Quote
publiusr - 4/5/2006  1:22 PMWhat is more, the current Cassini Titan probe needed both a good upper stage and gravity assist.If you want greater outer planet probes, you need a bigger rocket. It would probably take CaLV to do JIMO right, sample return missions from Mars (with margin) and Europa landers. We got away with the Delta II to Mars because that planet did us a favor by being nearby and had an atmosphere to aerobrake and pop a chute in.You won't do that with Europa. No cheating. You will have to dump speed and burn your way to the surface. By the time you are done you melt and deploy a cryobot about the same size as Spirit or Opp. That looks for smokers.So you need real heavy lift to orbit Kuiper objects, to land on Jovian moons, or to return Martian samples. Either that or these Rube Goldberg schemes people come up with who fall all over themselves to keep from admitting a need for greater lift.

What says aerobaking won't work at Europa.  If it has an atmosphere, aerobraking works.

Offline yinzer

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RE: The Shuttle Centaur
« Reply #22 on: 05/04/2006 06:08 PM »
Europa has no atmosphere.  Maybe a couple of microbars of atomic oxygen or something, but nothing you can aerobrake against.  Aerocapture against Jupiter is also quite hard, because it's so massive that orbital speed at the top of it's atmosphere is very, very high.  The radiation environment at and inside Io's orbit is also pretty nasty.
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Offline Jim

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RE: The Shuttle Centaur
« Reply #23 on: 05/04/2006 06:15 PM »
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yinzer - 4/5/2006  2:08 PMEuropa has no atmosphere.  Maybe a couple of microbars of atomic oxygen or something, but nothing you can aerobrake against.  Aerocapture against Jupiter is also quite hard, because it's so massive that orbital speed at the top of it's atmosphere is very, very high.  The radiation environment at and inside Io's orbit is also pretty nasty.

My bad, I was thinking of Titan

Offline HarryM

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RE: The Shuttle Centaur
« Reply #24 on: 05/04/2006 06:21 PM »
VERY tenuous atmosphere, one hundred billionth pressure of Earth's. Also it is mainly oxygen, which can be nasty impacting a metal structure at high speeds (recall some LDEF results I think which showed it's bad erosion effects in Earth orbit from free oxygen).

EDIT: Too slow! :)

Offline Spacely

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RE: The Shuttle Centaur
« Reply #25 on: 05/04/2006 06:53 PM »
Using expensive CaLV launches to lift aleady expensive (I'm talking 2-5 billion dollars here) sample return and outer planet orbiting missions seems like a catastrophic misuse of NASA funds, as such missions would essentially kill Space Science. We'd get, say, a Neptune Orbiter with Probes, and... well, that'd be it.

For a decade.

Why not invest upfront in the oft-tabled OTV instead of using precious CaLVs and hundreds of millions per launch?

http://www.astronautix.com/craft/otv.htm


Offline publiusr

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Re: The Shuttle Centaur
« Reply #26 on: 05/18/2006 07:06 PM »
I don't agree with that at all. Casseni isn't exactly cheap--and EELVs are too weak for JIMO and Europa lander missions. Look, we have funded 100 STS missions, each of which had lift-off thrust similar in power to Saturn V, and we have stayed in LEO. With CaLV subsituted for STS, with the same flight rate and the same or less costs as STS (no orbiter costs) the Solar System will open up to us in a way never before conceived. Naysaying only hobbles this.

BTW the OTV masses out to nearly 40 metric tons. What are you going to launch this with, besides CaLV?
You want to do EELV assembly, ISS style? Yeah--that style assembly really got Space Station finished in a hurry, didn't it?

I'll take single shot Skylab segments myself thank you. That was cheaper than ISS. Heavy Lift saves money, in launches, in assembly, in pad times, in engines, and in upper stages.

Offline Jim

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Re: The Shuttle Centaur
« Reply #27 on: 05/18/2006 07:16 PM »
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publiusr - 18/5/2006  2:53 PM

I don't agree with that at all. Casseni isn't exactly cheap--and EELVs are too weak for JIMO and Europa lander missions. Look, we have funded 100 STS missions, each of which had lift-off thrust similar in power to Saturn V, and we have stayed in LEO. With CaLV subsituted for STS, with the same flight rate and the same or less costs as STS (no orbiter costs) the Solar System will open up to us in a way never before conceived. Naysaying only hobbles this.

BTW the OTV masses out to nearly 40 metric tons. What are you going to launch this with, besides CaLV?
You want to do EELV assembly, ISS style? Yeah--that style assembly really got Space Station finished in a hurry, didn't it?

I'll take single shot Skylab segments myself thank you. That was cheaper than ISS. Heavy Lift saves money, in launches, in assembly, in pad times, in engines, and in upper stages.

How many Cassinis have there been?  NASA is only budgeting one per decade.  We couldn't afford 100 CaLV's of planetary missions.  $350 Billion

OTV was a shuttle lifted vehicle.

Offline Jim

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RE: The Shuttle Centaur
« Reply #28 on: 05/18/2006 07:19 PM »
Quote
Spacely - 4/5/2006  2:40 PM

Using expensive CaLV launches to lift aleady expensive (I'm talking 2-5 billion dollars here) sample return and outer planet orbiting missions seems like a catastrophic misuse of NASA funds, as such missions would essentially kill Space Science. We'd get, say, a Neptune Orbiter with Probes, and... well, that'd be it.

For a decade.

Why not invest upfront in the oft-tabled OTV instead of using precious CaLVs and hundreds of millions per launch?

http://www.astronautix.com/craft/otv.htm


Still need to get the payloads to the OTV and that will still take a CaLV

Offline publiusr

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RE: The Shuttle Centaur
« Reply #29 on: 05/18/2006 10:14 PM »
Quite true--and with CaLV you don't have to fund OTV--save a step, build it all on the ground and launch.

Remember, the HLLV thrust class Shuttle was to launch probes too. Magellan was an HLLV payload of sorts. With CaLV you lose the orbiter. OTV is for the far future if at all. OTV will have to be refueled as it stands, and EELVs will also cost a lot of money in that you use three times as many engines than CaLV and five times as many upper stages.

CaLV is an asset we need to truly open space up for us.

Offline Jim

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Re: The Shuttle Centaur
« Reply #30 on: 05/01/2010 02:54 PM »
Found some old pics
« Last Edit: 05/01/2010 02:55 PM by Jim »

Offline Jim

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Re: The Shuttle Centaur
« Reply #31 on: 05/01/2010 02:58 PM »
more

Offline Jim

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Re: The Shuttle Centaur
« Reply #32 on: 05/01/2010 02:59 PM »
ISPM became Ulysses

Offline Jim

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Re: The Shuttle Centaur
« Reply #33 on: 05/01/2010 03:01 PM »
Real hardware

Offline missleman01

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Re: The Shuttle Centaur
« Reply #34 on: 05/01/2010 05:03 PM »
One with its payload bay cradle is on display next to pathfinder at the space and rocket center in Huntsville.

http://historicspacecraft.com/Photos/Upper_Stage/Centaur_USSRC_RK_2008_1.jpg

Offline Blackstar

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Re: The Shuttle Centaur
« Reply #35 on: 05/01/2010 05:15 PM »
Oh, those are nice!

I've whined about this before, but I'll do so again: there's no good history explaining why--with citations--the Shuttle Centaur was canceled.  The few accounts that I have read essentially say "after Challenger, the astronauts objected and it was eliminated."  But there had to be meetings where it was discussed, and data that was presented.

Online DaveS

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Re: The Shuttle Centaur
« Reply #36 on: 05/01/2010 05:23 PM »
Very nice find Jim! Blackstar: Read the NASA SP Taming Liquid Hydrogen, The Centaur Upper Stage Rocket: http://history.nasa.gov/SP-4230.pdf

The answer you want is in Chapter 7, Eclipsed by Tragedy, page 206.
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Offline Jim

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Re: The Shuttle Centaur
« Reply #37 on: 05/01/2010 07:22 PM »
I also got a document call Centaur G-Prime Technical Description.  Unfortunately, it is spiral bound.

Online DaveS

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Re: The Shuttle Centaur
« Reply #38 on: 05/01/2010 08:37 PM »
I also got a document call Centaur G-Prime Technical Description.  Unfortunately, it is spiral bound.
So no scans :( ? Hmmm, after checking these new images, especially the scale model ones, I notice several things.

The main one is that the model's LH2 F/D line has a Y manifold, whereas the display Centaur does not. And one the model the GH2 vent line goes all the way to the top of the LH2 tank, whereas on the display Centaur the GH2 vent line is significantly shorter and only goes to the bottom of the LH2 tank.
"For Sardines, space is no problem!"
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"We're rolling in the wrong direction but for the right reasons"
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Offline Jim

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Re: The Shuttle Centaur
« Reply #39 on: 05/01/2010 08:50 PM »
Now that I have the document, you can ask away.

The model is old.  The GH2 vent line is internal to the tank and there is no Y.

I also got the top level configuration drawings.

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