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#540
by
Galactic Penguin SST
on 29 Jun, 2012 10:28
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From today's launch (attempt?), what's a SMTU battery?
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#541
by
spacenut
on 25 Jul, 2012 13:55
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What is the Delta IV heavy LEO payload with the new upgraded engines? What would it's payload be with a 5m upgraded Centaur second stage if it is ever developed?
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#542
by
Ben the Space Brit
on 25 Jul, 2012 14:16
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I think that the payload to LEO with the four-engine Common Centaur and 6 GEMs is in the 40-50 metric tonne range. I don't know if the new RL-10 gives any significant change in overall performance as it has lower Isp than RL-10B-2 but better thrust.
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#543
by
WHAP
on 25 Jul, 2012 14:41
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I think that the payload to LEO with the four-engine Common Centaur and 6 GEMs is in the 40-50 metric tonne range. I don't know if the new RL-10 gives any significant change in overall performance as it has lower Isp than RL-10B-2 but better thrust.
I think the OP was referring to the RS-68A, not a new RL-10 (but I could be wrong). Where are people getting performance for this RL-10? There was discussion about a new RL-10 over on the PWR sale thread, too. Seems odd that anyone would build a new engine with lower Isp but higher thrust, since Isp is more important for the upperstage (although thrust is probably more important for LEO).
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#544
by
Ben the Space Brit
on 25 Jul, 2012 15:46
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I'm not sure but, IIRC, the variant is called RL-10C and it's supposed to be 30klbf and 450s vacuum impulse. PWR have been advertising it for a while but only recently has DoD shown any interest - the New Generation Engine (NGE) project. RL-10C isn't certain to win but you've got to think it has an advantage.
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#545
by
kevin-rf
on 25 Jul, 2012 16:06
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Greater LEO payload assumes that it is not limited by the structural limits of the vehicle.
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#546
by
MP99
on 25 Jul, 2012 16:14
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I'm not sure but, IIRC, the variant is called RL-10C and it's supposed to be 30klbf and 450s vacuum impulse. PWR have been advertising it for a while but only recently has DoD shown any interest - the New Generation Engine (NGE) project. RL-10C isn't certain to win but you've got to think it has an advantage.
RL-10C isn't NGE, and it's not 30klbf.
Suspect that's the target thrust for NGE, which is at proposal stage at the moment I think.
cheers, Martin
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#547
by
spacenut
on 25 Jul, 2012 20:05
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I was refering to the RS-68A. Currently the Delta IV heavy in standard configuration is 29 tons to LEO. Just wondering how much increase with the new engines. Then with the new engines and a new upper stage. Without Gems. Then maybe with Gems. I was thinking it has greater capability for LEO and L1 or L2 station building capability with the 5m + width of payload. If things don't change soon, I don't see SLS being built anytime soon. Just wanted to know if we could use the Delta IV heavy for some space exploration with equipment and spacecraft launched to dock with using commercial. then go beyond LEO without SLS.
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#548
by
mmeijeri
on 25 Jul, 2012 20:30
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Just wanted to know if we could use the Delta IV heavy for some space exploration with equipment and spacecraft launched to dock with using commercial. then go beyond LEO without SLS.
Sure you can. Centaur would be a good EDS for small payloads, and that's all you really need if you use Lagrange point staging. It's a bit small, too small for Orion, but not unworkably small. The Centaur-derived ACES would be
excellent, but plain old Centaur would do.
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#549
by
baldusi
on 25 Jul, 2012 20:40
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I was refering to the RS-68A. Currently the Delta IV heavy in standard configuration is 29 tons to LEO. Just wondering how much increase with the new engines. Then with the new engines and a new upper stage. Without Gems. Then maybe with Gems. I was thinking it has greater capability for LEO and L1 or L2 station building capability with the 5m + width of payload. If things don't change soon, I don't see SLS being built anytime soon. Just wanted to know if we could use the Delta IV heavy for some space exploration with equipment and spacecraft launched to dock with using commercial. then go beyond LEO without SLS.
RS-68 is around 23 tonnes to LEO, RS-68A was expected to be around 29tonnes to LEO. It's anyone's guess at this time.
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#550
by
mmeijeri
on 25 Jul, 2012 21:22
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RS-68A was expected to be around 29tonnes to LEO.
If it's that much, you could even use a 5m Delta upper stage. You couldn't get it to orbit fully fueled, but you could get it to orbit with significantly more propellant than a Centaur.
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#551
by
spacenut
on 26 Jul, 2012 15:28
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I was thinking if they built a 5m upper stage on the Centaur design for efficiency using a common bulkhead design instead of separate tanks. Would that improve payload? Then when you add solids or have crossfeed to central core I was wondering if this could be done incrementally to get to 50 tons?
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#552
by
Downix
on 26 Jul, 2012 16:16
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I was thinking if they built a 5m upper stage on the Centaur design for efficiency using a common bulkhead design instead of separate tanks. Would that improve payload? Then when you add solids or have crossfeed to central core I was wondering if this could be done incrementally to get to 50 tons?
Congrats, you just describes the next-gen upper stage being developed by ULA, ACES:
http://www.ulalaunch.com/site/docs/publications/UpperStageEvolutionJPC2009.pdf
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#553
by
spacenut
on 27 Jul, 2012 14:00
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How soon will the new upper stage be developed? Seems like if this takes place, SLS will not be needed. Money spent there could be used for in space equipment to get the show on the road.
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#554
by
edkyle99
on 27 Jul, 2012 15:22
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How soon will the new upper stage be developed? Seems like if this takes place, SLS will not be needed. Money spent there could be used for in space equipment to get the show on the road.
ACES was a proposal, several years old now. It isn't being developed to my knowledge. SLS may end up with an in-space stage that looks a bit like a version of ACES, but it hasn't been put up for bids (won't for awhile now) and once competed there is no guarantee that ULA's (Lockheed Martin's) balloon tank concept would be the winner. Boeing has proposed a rigid tank alternative.
- Ed Kyle
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#555
by
baldusi
on 27 Jul, 2012 16:39
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ULA is working on the Integrate Fluid Vehicle concept. Is cooperating on with XCOR with a piston pumped H2/LOX rocket engine, and has contracted an auto manufacturer for a four piston GH2/GOX engine for electricity generation. So I don't know if exactly ACES, but a pretty close thing is being worked on. Since there's no extra money, it's being done slow. But they are working. I remember Downix stating that ULA would work on the Delta IV Fleet Standardization Program (CDR on October), then on ACES, and then on Atals V Phase 2. Since they are investing out of their own pocket, they are doing it slow. So ACES might be a 2020 IOC, and who know about AVP2.
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#556
by
Downix
on 27 Jul, 2012 17:06
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ULA is working on the Integrate Fluid Vehicle concept. Is cooperating on with XCOR with a piston pumped H2/LOX rocket engine, and has contracted an auto manufacturer for a four piston GH2/GOX engine for electricity generation. So I don't know if exactly ACES, but a pretty close thing is being worked on. Since there's no extra money, it's being done slow. But they are working. I remember Downix stating that ULA would work on the Delta IV Fleet Standardization Program (CDR on October), then on ACES, and then on Atals V Phase 2. Since they are investing out of their own pocket, they are doing it slow. So ACES might be a 2020 IOC, and who know about AVP2.
That is what they have detailed in the upgrade path document I linked to above anyways. Ed is right that Boeing did propose a rigid tank alternative, mind you, but until the fleet standardization is completed, I would not expect either path to be explored.
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#557
by
DGH
on 02 Sep, 2012 17:43
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This may be a crazy question but with an increase of 50,000 lbs of thrust with the new RS-68A and the desire to use the smaller second stage from the Atlas saving about 10,000 lbs how hard would it be to add another 30,000-70,000 lbs to the first stage?
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#558
by
Prober
on 17 Sep, 2012 14:36
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This thread is a much better read than the Atlas Q&A....more space launch drama...ehhehe.
Not found my question asked so here goes.
Did the Centaur G Prime Influence the Second stage design of the Delta IV?
The General looks are of a "clone" with different materials.
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#559
by
Jim
on 17 Sep, 2012 15:31
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This thread is a much better read than the Atlas Q&A....more space launch drama...ehhehe.
Not found my question asked so here goes.
Did the Centaur G Prime Influence the Second stage design of the Delta IV?
The General looks are of a "clone" with different materials.
No. The HDCSS was an upgrade of the DCSS of Delta III. The Centaur G Prime had a common bulkhead and HDCSS has separate tanks connected by a truss. Plus they were designed by different contractors.