Ideally you would want to have:1. A reliable, fully tested and tried system2. A system capable of handling heavy loads3. A system that could fire for long periods of time without stopping4. A system that used as little propellant and electricty as possible with greatest thrust possible.
Constellation has all its propulsion needs decided.RS-68, J-2X
Quote from: Jim on 12/01/2009 08:26 pmConstellation has all its propulsion needs decided.RS-68, J-2XIsn't that jumping the gun a little?? Ares V is still up in the air I mean...It might be 'baselined' but the current RS-68 config doesn't work (due to base heating).
Quote from: robertross on 12/01/2009 09:24 pmQuote from: Jim on 12/01/2009 08:26 pmConstellation has all its propulsion needs decided.RS-68, J-2XIsn't that jumping the gun a little?? Ares V is still up in the air I mean...It might be 'baselined' but the current RS-68 config doesn't work (due to base heating). In that case the engine would still be derived from an existing one (either RS-68 or SSME).
Quote from: robertross on 12/01/2009 09:24 pmQuote from: Jim on 12/01/2009 08:26 pmConstellation has all its propulsion needs decided.RS-68, J-2XIsn't that jumping the gun a little?? Ares V is still up in the air I mean...It might be 'baselined' but the current RS-68 config doesn't work (due to base heating). This has not been confirmed by NASA ... ever.
Quote from: marsavian on 12/01/2009 11:17 pmQuote from: robertross on 12/01/2009 09:24 pmQuote from: Jim on 12/01/2009 08:26 pmConstellation has all its propulsion needs decided.RS-68, J-2XIsn't that jumping the gun a little?? Ares V is still up in the air I mean...It might be 'baselined' but the current RS-68 config doesn't work (due to base heating). This has not been confirmed by NASA ... ever.Yes, and like so many things never confirmed by NASA, I too rely on Chris' sources & NSF for the best information around. ALl signs point to YES, base heating is a problem for the non-regen RS-68, which is the PoR.
Quote from: Jorge on 12/01/2009 11:12 pmQuote from: robertross on 12/01/2009 09:24 pmQuote from: Jim on 12/01/2009 08:26 pmConstellation has all its propulsion needs decided.RS-68, J-2XIsn't that jumping the gun a little?? Ares V is still up in the air I mean...It might be 'baselined' but the current RS-68 config doesn't work (due to base heating). In that case the engine would still be derived from an existing one (either RS-68 or SSME).Yes, that's my point. SSME isn't on the list, so Jim's list isn't exactly 'decided' for Ares V.
A problem and not working are not the same thing.
Quote from: marsavian on 12/01/2009 11:30 pmA problem and not working are not the same thing.And the solution?1) Modified engine2) New engineHence my point for Jim's post jumping the gun; it was an absolute. It is NOT 'carved in stone' yet.If they change rockets now, is it still considered Constellation? If they select & call Jupiter an Ares IV and make it part of Constellation, could there not be a change in engines?
Quote from: robertross on 12/01/2009 11:37 pmQuote from: marsavian on 12/01/2009 11:30 pmA problem and not working are not the same thing.And the solution?1) Modified engine2) New engineHence my point for Jim's post jumping the gun; it was an absolute. It is NOT 'carved in stone' yet.If they change rockets now, is it still considered Constellation? If they select & call Jupiter an Ares IV and make it part of Constellation, could there not be a change in engines?No.You are still assuming the current RS-68s won't work when it is still a work in progress like TO ...http://www.nasaspaceflight.com/2008/12/ssme-ares-v-undergoes-evaluation-potential-switch/
5. The upper most engine (short of the service module engine) for deep space propulsion would be something similar to the VX200 (though it could use nuclear, ion, antimatter, netrino, plasma, ect. as the primary propellant.)
Quote from: FinalFrontier on 12/02/2009 12:50 am5. The upper most engine (short of the service module engine) for deep space propulsion would be something similar to the VX200 (though it could use nuclear, ion, antimatter, netrino, plasma, ect. as the primary propellant.) for Constellation, that is the J-2X. Constellation is not an advanced propulsion program. Talk of any other system is outside of the constellation program
So you are saying that any option that is not a J-2X cannot fit into a modified/evolved form of Constellation?