So, how much engine out capability do you want? j/k If anything, politicians need to learn the value of a 2.0 architecture, with a common rocket. There are so many cost savings.In this case, the cost of 5x disposable J-2X gets VERY costly...
So, let's say politicians keep Ares I and the 1.5 architecture going but the RS-68 Ares V proves too expensive and late because of needing regen engines. Why not take Ares V classic and add a 5 * J2-X middle stage so it really is more like Saturn V. The LEO payload would say be 140-150mT LEO and perhaps 1.5 couldn't do everything they thought originally but still do most of it and they could do a two launch Ares V mission profile for those it couldn't. That would work for Cx's goals wouldn't it while still remaining true to ESAS's conclusions ? Discuss .
Quote from: marsavian on 11/01/2009 04:33 pmSo, let's say politicians keep Ares I and the 1.5 architecture going but the RS-68 Ares V proves too expensive and late because of needing regen engines. Why not take Ares V classic and add a 5 * J2-X middle stage so it really is more like Saturn V. The LEO payload would say be 140-150mT LEO and perhaps 1.5 couldn't do everything they thought originally but still do most of it and they could do a two launch Ares V mission profile for those it couldn't. That would work for Cx's goals wouldn't it while still remaining true to ESAS's conclusions ? Discuss .Are you talking about an Ares V "Lite". I keep hearing about this, but haven't seen a specification from Nasa. I'm assuming the core will be a smaller 8.4m. By the way, I like the idea.
Quote from: kyle_baron on 11/03/2009 07:40 pmQuote from: marsavian on 11/01/2009 04:33 pmSo, let's say politicians keep Ares I and the 1.5 architecture going but the RS-68 Ares V proves too expensive and late because of needing regen engines. Why not take Ares V classic and add a 5 * J2-X middle stage so it really is more like Saturn V. The LEO payload would say be 140-150mT LEO and perhaps 1.5 couldn't do everything they thought originally but still do most of it and they could do a two launch Ares V mission profile for those it couldn't. That would work for Cx's goals wouldn't it while still remaining true to ESAS's conclusions ? Discuss .Are you talking about an Ares V "Lite". I keep hearing about this, but haven't seen a specification from Nasa. I'm assuming the core will be a smaller 8.4m. By the way, I like the idea.There have been several bantered about, but the one I hear the most is the 5 RS-68 on 10m tank w/ 5-seg SRB.
It might not be human rateable to modern NASA standards with that many engines and staging events.Manrating Standards can change, ask Ares I . This concept is already proven with Saturn V, it would need to fly a few times to get confidence with it.
If you also chose to go 10-11m at the same time it opens up the possibility of doing a two-stage Ares IX with 9 SSME/RS-25Es in the first stage and a single J2-X upper stage instead of this three stage.
Oh, that's obviously a horrible idea on an Ares V or anything else in the PoR, but a great idea if we're talking about a J-3551 SH.
While NASA has recently been suggesting an Ares V Lite with 5 RS-68, a 10m tank, and 5 seg SRBs, we're really talking about the slightly smaller original ESAS-era Ares V "Classic" in this thread: 5 SSME, 5 seg SRB, 8.4m shuttle-derived tank stretched to match the SRBs. Ares V classic would be a 120t launcher, Ares V Lite a 140t launcher, and the current full Nasa Ares V would be a 160t launcher. (And for completeness sake, the next step down would be a 100t J-241).
With the addition of a 3rd stage, I'm wondering, is there enough fuel left over to use the EDS for LOI, and as a brake, to slow the Altair-CLV stack into a lunar orbit? This is with Ares 1, and a 1.5 launch architecture.
Quote from: kyle_baron on 11/07/2009 08:18 pmWith the addition of a 3rd stage, I'm wondering, is there enough fuel left over to use the EDS for LOI, and as a brake, to slow the Altair-CLV stack into a lunar orbit? This is with Ares 1, and a 1.5 launch architecture.Presuming that you end up with a lighter EDS / third stage, then you reduce the penalty for retaining the EDS through LOI.cheers, Martin
Ares V Lite is ~140mT gross, or ~140mT net including EDS burnout.Ares V Classic is 125mT net excluding EDS. Ross reports the performance as nearly identical to AVL, and http://www.paul.enutrofal.com/sheet1.html estimates 147mT gross to LEO (according to CEPE).Both vehicles have a 55mT through-TLI performance (as reported by Augustine & ESAS, respectively).cheers, Martin
I don't think it is, ESAS Ares V Classic used HTPB SRBs ...
Quote from: marsavian on 11/16/2009 04:57 pmI don't think it is, ESAS Ares V Classic used HTPB SRBs ... I just noticed that in this diagram it is listing the J-2S as having higher performance than the J-2X. I've not compared the two, but I'd always figured that the J-2X was better than the J-2S.
Quote from: Downix on 11/16/2009 05:09 pmQuote from: marsavian on 11/16/2009 04:57 pmI don't think it is, ESAS Ares V Classic used HTPB SRBs ... I just noticed that in this diagram it is listing the J-2S as having higher performance than the J-2X. I've not compared the two, but I'd always figured that the J-2X was better than the J-2S.Define 'listing'.
Quote from: MP99 on 11/15/2009 01:41 pmQuote from: kyle_baron on 11/07/2009 08:18 pmWith the addition of a 3rd stage, I'm wondering, is there enough fuel left over to use the EDS for LOI, and as a brake, to slow the Altair-CLV stack into a lunar orbit? This is with Ares 1, and a 1.5 launch architecture.Presuming that you end up with a lighter EDS / third stage, then you reduce the penalty for retaining the EDS through LOI.cheers, MartinSince you didn't answer yes or no, I assume you mean maybe?
Presuming that you end up with a lighter EDS / third stage, then you reduce the penalty for retaining the EDS through LOI.If your lander is sized for a 2-stage launcher, then it can't perform LOI & descent with a larger payload. You'd either need to re-scale the lander, or have the EDS perform LOI.
Quote from: marsavian on 11/16/2009 05:56 pmQuote from: Downix on 11/16/2009 05:09 pmQuote from: marsavian on 11/16/2009 04:57 pmI don't think it is, ESAS Ares V Classic used HTPB SRBs ... I just noticed that in this diagram it is listing the J-2S as having higher performance than the J-2X. I've not compared the two, but I'd always figured that the J-2X was better than the J-2S.Define 'listing'.The second one in from the left has a single J-2S listed as the second stage engine. To the immediate right of it is the same configuration, but with a single J-2X, with a noticeable performance loss.
Quote from: Downix on 11/16/2009 06:34 pmQuote from: marsavian on 11/16/2009 05:56 pmQuote from: Downix on 11/16/2009 05:09 pmQuote from: marsavian on 11/16/2009 04:57 pmI don't think it is, ESAS Ares V Classic used HTPB SRBs ... I just noticed that in this diagram it is listing the J-2S as having higher performance than the J-2X. I've not compared the two, but I'd always figured that the J-2X was better than the J-2S.Define 'listing'.The second one in from the left has a single J-2S listed as the second stage engine. To the immediate right of it is the same configuration, but with a single J-2X, with a noticeable performance loss.It's not the same configuration, the SSMEs have 0.6s lower Isp and more importantly the ESAS Ares V (with J2-S) uses HTPB RSRM propellant as opposed to PBAN which was my original point. This is why the PBAN Ares V Classic was dropped for the original RS-68 Ares V which is very similar to Ares V lite.
1) I'm surprised at the size of the payload drop. Any thoughts how much of that is from dropping HTPB, and how much from the RS-25 Isp drop?
I just noticed that in this diagram it is listing the J-2S as having higher performance than the J-2X. I've not compared the two, but I'd always figured that the J-2X was better than the J-2S.
Would a 2x J-2X config out-perform 1x J-2X? (Compensate for the lower core performance).cheers, Martin