Since the Direct baseline architecture is 2 J-246's, with two JUS's, one fully fueled, one fueled just enough for LEO of CEV/LSAM.Could both JUS's be partially fueled, and have a rendevous in LE1 or LLO? You have to expend two anyway, couldn't the docking procedures be simplified that way? Also, in that vein, if a Centaur or D4US (are they the same? Don't know much about them, if they are two terms for the same upper stage or not) can take Orion around the moon for an Apollo 8 type flyby, could one be used to take the LSAM there too, again for a LE1 or LLO rendevous?I know fueled LSAM is heavier than Orion, so I don't know.But now I'm curious.
The Direct team mentioned that someone had verified Direct's claims to performance with 1%. Will they ever publish the review\study before the Commission is finished in Auguest?
Which reminds me -- I just heard that NASA has gone and produced a new "Analysis" into DIRECT 3.0 in which the same old BS is apparently doing the rounds -- yet again.While I've only heard a few details, they're b*tching about the pmf being something which NASA is unable to build (yeah, we know that, which is precisely why we want Industry to handle that element because of their much greater experience instead, duh!).And they're trying to depict the architecture as only being able to send a 29mT lander through TLI.I find these claims to be quite remarkable when you consider that ESAS itself included a configuration rather similar to Jupiter-246 (LV-25 + EDS S1A = Jupiter-234, which uses just three SSME's on the Core (4 is much better) and four RL-60-class engines on the EDS). Yet, even with less performance than the DIRECT configurations this vehicle is sufficient, in 2-launch profile, to comfortably exceed CxP's current performance requirements of 71.1mT thru TLI. In fact, ESAS claims the lower-power configuration can actually send 74.3mT thru TLI. See attached.I find it just "amazing" how, suddenly, this sort of vehicle magically "loses" about 15 tons of performance as soon as it threatens the Ares systems. Just amazing, that, eh?Seems the BS continues to be shoveled to anyone willing to swallow it. Jeez.Ross.
Seen this in Today's Florida Today -- Editorial Cartoons" section?Its just *begging* to have a couple of photo re-touches... Adding names to the back of shirts etc...Ross.
Quote from: PaulL on 06/24/2009 11:42 amRoss, would it help if the structure of the Jupiter rocket was lighter/optimized for the J-130 instead of the J-246? What I am thinking here is designing a lighter Jupiter core able to be fitted with 2 optional vertical support beams for the J-246 version. These support beams, which would be bolted on the core in the VAB, would be placed 90 degrees from the SRBs. The beams would be able to support the extra mass of the US on top of the LO2 tank and the extra compression on the LH2 tank caused by the 4th SSME.PaulL As soon as you optimize for the J-130 you create a *new* launch vehicle and the cost savings for DIRECT go away. Even though the 2 LVs (J-130 and J-246) would look very similar, they would in fact be 2 different vehicles and we will have lost the foundational fundamental fo DIRECT: build ONE launch vehicle able to do both jobs.That's actually one of our major fears; that after NASA adopts DIRECT, they will optimize the J-130, as you suggest. We do NOT advocate that. It's spending money (a lot of money) for nothing.
Ross, would it help if the structure of the Jupiter rocket was lighter/optimized for the J-130 instead of the J-246? What I am thinking here is designing a lighter Jupiter core able to be fitted with 2 optional vertical support beams for the J-246 version. These support beams, which would be bolted on the core in the VAB, would be placed 90 degrees from the SRBs. The beams would be able to support the extra mass of the US on top of the LO2 tank and the extra compression on the LH2 tank caused by the 4th SSME.PaulL
Okay, to lighten the mood... Who's seen this in Today's Florida Today -- Editorial Cartoons" section?Its just *begging* to have a couple of photo re-touches... Adding names to the back of shirts etc...Ross.
Call me strange or peculiar (and some might), but even though I respect the old guy for his accomplishments before I was born, I'm still going to hire the guy who has successfully built the 757, 767, 777 and now the 787, not the guy who's last involvement in this business was on the 707.Ross.
I am not looking here at developing 2 Jupiter cores. What I am suggesting is to develop a lighther core which could be used with 3 SSME engines and an engine plug for the J-130. The same core could be used with 4 SSME engines, two vertical support beams and an upper stage to create a J-24x. The idea here is to permit the use of the J-130 for the lunar CEV+LSAM flight. The EDS flight on a J-24x is not the problem here as it has plenty of margin compared to the J-130 CLV flight.
Quote from: kraisee on 06/24/2009 09:19 pmSeems the BS continues to be shoveled to anyone willing to swallow it. Jeez.Ross.Sad part is, they're NASA, they can get away with it. If you try to argue they "fudged" the numbers in Ares' favor, then you guys look like your trying to start conspiracy theories. Let's just hope the panel can see through these types of things. But I have the pessimistic feeling they won't.The funny part is, if Jupiter is chosen, we get to see NASA say, "WOW! We just found 15 extra tons of performance! Were did that come from?!?!?"
Seems the BS continues to be shoveled to anyone willing to swallow it. Jeez.Ross.
Quote from: gladiator1332 on 06/24/2009 09:27 pmQuote from: kraisee on 06/24/2009 09:19 pmJeez.too heavy on science, which begs the question if there was some purpose to that? (robertross said this (I missed with the scissors.))
Quote from: kraisee on 06/24/2009 09:19 pmJeez.too heavy on science, which begs the question if there was some purpose to that? (robertross said this (I missed with the scissors.))
Jeez.
Quote from: robertross on 06/24/2009 09:50 pmQuote from: gladiator1332 on 06/24/2009 09:27 pmQuote from: kraisee on 06/24/2009 09:19 pmJeez.too heavy on science, which begs the question if there was some purpose to that? (robertross said this (I missed with the scissors.))I think it is clear that the presentation was a rushed 1/2 hour version of an hour presentation that was cut to 20 minutes right at the last second. A lot of good points were made, however, in that limited time.
None of the ESAS TLI claims have proved accurate including Ares V which has had to be enlarged considerably from the SSME Classic to what they have now and it still comes up short so you can't rely on ESAS.
Ares V classic wasn't dumped because of a performance deficit (it probably would have worked pretty well), it was dumped on a supposed cost of engine basis. So, NASA picked less efficient engines, and then wondered why making Ares V bigger and bigger wasn't having the desired effect... it didn't help any that upgrades to the RS-68 weren't hitting their performance targets (per Ross statements), or that the core stage was too heavy for the crawlerway.Ares I on the other hand, was dumped because the upper stage engine supposedly couldn't be made to air start, so they picked a less efficient engine, made the first stage bigger, and wondered why making the thing bigger wasn't having the desired effect... it didn't help any that the J-2X design was having a hard time hitting its performance targets (again, per Ross' statements), or that the first stage was too long to avoid resonance with the upper stage.I don't know for sure what the real (as opposed to supposed) motivation was for dumping Space Shuttle Main Engines, Space Shuttle External Tanks (or at least very close approximations), and Space Shuttle SRBs from vehicles that were supposed to be Space Shuttle derived, but replacing them with unbuilt (hence needed development), untested (hence unknown performance), and unproven (hence unknown reliability) hardware sure has made the whole process a lot more complicated