I just had a odd thought.Things started to go bad for Ares 1 once they ran into problem with the air startable SSME,
[...] they could have still made the A1US, but it would be common with the Ares 1 liquid booster then.
[...] don't worry about the big solid
My data recorder says different ! Things started to go bad for Ares I, and for the whole Constellation program, when NASA realized that the administration would not fund the program as promised. More, Shuttle return to flight and other contingencies further diminished the available funding.The solution was to reduce the number of program elements, to eliminate expensive elements, to enforce commonalities between CLV and CaLV, to find commonalities with external programs. From 3 liquid fuel engine elements (RS-25 air start, RS-25 ground start, J-2S) they went to 2 (RS-68, J-2X).
This is quite a stretch. An upper stage must be optimized or it would not reach orbit with a significant payload, or at all.
That would have been a bug, not a feature - wrt politics. The Constellation program was designed such that it would keep the "big solid" in the big picture. CLV was the funded project, not CaLV.
In theory, yes, but it would have failed in the ESAS guidelines they put down, namely "one engine per stage."Anything more than that, then the ESAS would have been shown to have been in error, and could have opened up the entire thing to lawsuits by the losers of the competition.
I'll take one last hail Mary pass at it though. Given that a big solid was required and an RS-25 couldn't feasible be made to air start.Maybe take a Delta IV core, modify it with a single RS-25 engine, and side mount it to an SRB with the RS-25 angled outwards like the Shuttle's were. The SRB's are designed to be side mounted anyway, although obviously it wouldn't quite be the same. But should be any harder than trying to inline mount it.Then you remove the air-startable RS-25, and the J2X. Ares 1 and Ares V both use RS-25 and SRB's. You remove the extra 5.5m upper stage development too. With one RS-25, the Delta IV core should burn to disposable orbit, and then on ISS support missions, Orion does it's own EOI burn to get to the ISS.For Lunar missions, maybe an EELV upper stage is used, or the Service Module is designed with enough prop to get itself to EOR, and then the TEI burn from LLO. Put Orion above the top of the SRB So that it's not next to it...which would be undesirable.Not that it would be a good LV...but perhaps more workable than Ares 1?
He he... great minds think alike LOL !Lobo, search this forum for "1 1/2 SD CLV" and you'll see the same crazy ideea explored 6 years ago.Or something much like that.I even toyed with moving the Lox tank out-of-axis wrt. the H2 tank so that the c-of-m would be as close as possible to the SRB axis; and that was because one of the critics said that if the RS-25 quits in the early stage, the rocket goes cartwheel.But the basic principle still haunts me occasionally !Yes, with such a stage-and-a-half-to-orbit CLV design,- you have the great RS-25, ground started and firing all the way to orbit;- you can adjust the sizing of liquid propellant tanks without growing to monster height, because the LH2 tank lies parallel to the SRB; - you have Orion on topSince this is a speculation thread, I will attach some of the graphics that I used to play with at the time, and no one needs to feel offended, OK ?Just having fun !
Quote from: Downix on 06/15/2013 05:38 pmIn theory, yes, but it would have failed in the ESAS guidelines they put down, namely "one engine per stage."Anything more than that, then the ESAS would have been shown to have been in error, and could have opened up the entire thing to lawsuits by the losers of the competition.Is that true?I'm trying to remember the ESAS report off the top of my head. They looked at several multi-engine per stage CLV's, and although they rejected them for various reasons, I don't recall one of the reasons was multiple engines per stage. They looked at Atlas V Phase 2 which had two RD-180's. And an 8m Atlas V with like 5 RD-180's on the core. they also looked at D4H and A5H. They each would have 3 engines on the first stage. They showed them with existing DCSS and centaur, and with new larger upper stages (ACES-like I think) that I think had multiple RL-10's on them. But I'd have to go back and look at it when I get time.They seemed to evaluate a lot of multi engine CLV's and rejected them for various "reliability" and "black zone" and other reasons. I don't recall engine count being a reason for the rejections though?
I wonder if Aries 1 could have found some use as a cargo-only vessel, assuming that it would be realized that the mass of the LES would compromise the design of orion too much.
Actually the 1.5 launch decision.If they were willing to go with two HLV launches , use SEP tugs, or fuel depots for future capability etc they might have avoided disaster.
But then it would have not been a legacy design and all the talks they had had been in vain. What's more, they went with that architecture only after a trade with very strict criteria, that not even Ares 1 met. After the restartable RS-25 failed to realize, they should have done the trades again, or go with the second best. They did neither.
Quote from: baldusi on 02/12/2014 10:20 pmBut then it would have not been a legacy design and all the talks they had had been in vain. What's more, they went with that architecture only after a trade with very strict criteria, that not even Ares 1 met. After the restartable RS-25 failed to realize, they should have done the trades again, or go with the second best. They did neither.Yea, it wouldn't have been all legacy, but this entire thread is about hypothetical ways things may have been "different". You still have same sized boosters that are still solids. I just wonder whether and how well it might have worked from a technical standpoint.Things like: Would advanced propellants in a composite casing have had better or worse oscillation? Could it have been dampened? etc.
In aerospace projects, 90% of costs are incurred in the first 10% of the program.-snip-
Quote from: Patchouli on 12/31/2013 02:51 amActually the 1.5 launch decision.If they were willing to go with two HLV launches , use SEP tugs, or fuel depots for future capability etc they might have avoided disaster.No SEP or depots needed. Two 95 ton launchers where more than enough as well as cheaper than AresV/ Ares I.