Author Topic: Upper Stage for SLS  (Read 54404 times)

Offline Halidon

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Re: Upper Stage for SLS
« Reply #120 on: 10/21/2010 10:06 pm »
FWIW, it should be remembered that SpaceX's Raptor is currently blueprints at most, and would be manufactured by a company with no prior hydrolox experience.  Naturally, no non-US engine would even be considered for a 'flagship' like SLS.

So, I'm afraid something PWR or Aerojet is pretty much the only game in town right now.
They didn't have any RP-1 experience before 2002. If this upper stage is anything like 8 years away, like if we fly the HLV without an US for LEO work initially, Raptor may be right there waiting.

Offline sdsds

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Re: Upper Stage for SLS
« Reply #121 on: 11/05/2010 06:17 am »
A custom-sized J-2X stage would be great, but what can be done until it becomes available?

If the SLS vehicle performed like a Jupiter 130H (i.e. 85.603 metric tons to 51.5x130nm at 29deg), it could loft two of the smaller Delta IV upper stages plus a 30 metric ton payload.  The two stages, fired sequentially or in parallel, could send the payload to Earth-escape velocity, so it could easily be sent through a standard TLI, or on a ballistic trajectory to EML1 or EML2.
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Offline Patchouli

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Re: Upper Stage for SLS
« Reply #122 on: 11/05/2010 09:45 pm »
The goal is to design the core only once, qualify it and fly it until SLS itself is replaced 40 years from now. Follow the Soyuz model; build it once - fly it forever. Let all subsequent development be in the upper stage(s).

Or the Enegria /Starlifter model

The Energia family could produce a 35, 100 and 175T LV using the same parts.
http://www.buran-energia.com/energia/famille-desc.php


Starlifter on the other hand allows an incremental move to reusability.
http://www.starbooster.com/StarLifter_I.pdf

Spacex's Merlin 2 could be used as a replacement for the RD-170 a stretched F9 or Atlas CCB should work for the tanks.

For an upper stage the RL-60 and even the RL-10 beats any J-2 based solution hands down.

SDLVs with SSMEs tend to be stage and a half to orbit vehicles so they don't need a high thrust upper stage ISP is going to be far more important.

FWIW, it should be remembered that SpaceX's Raptor is currently blueprints at most, and would be manufactured by a company with no prior hydrolox experience.  Naturally, no non-US engine would even be considered for a 'flagship' like SLS.

So, I'm afraid something PWR or Aerojet is pretty much the only game in town right now.
They didn't have any RP-1 experience before 2002. If this upper stage is anything like 8 years away, like if we fly the HLV without an US for LEO work initially, Raptor may be right there waiting.

The most useful thing Spacex might have to contribute to SLS would be Merlin 2 vs Raptor.

The reason why is Merlin 2 would create another alternative to the RSRM for booster use even better then the RD-180.

Raptor would not really be much of an improvement over six RL-10s and in fact could have lower TLI performance if it's ISP turns out being much lower then the RL-10.

On the Jupiter vehicles which probably represent a good idea of what SLS will be the RL-10 does outperform the J-2X for lunar missions.


« Last Edit: 11/06/2010 03:47 am by Patchouli »

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