Jamie Young - 18/1/2006 9:22 PMWhy do they need to make a bigger booster??
Lunar Dreamer - 18/1/2006 3:07 PMDon't know about falling apart, but if you read NASAwatch you would think so. It's hardly looking good!
JulesVerneATV - 2/2/2006 11:37 AMNo VSE, Red Planet, no manned flights to the Moon and Mars were not to be found in this year's Union address but President Bush laid out an agenda that warned against isolationism, urged Americans to stay in Iraq, and reforms social security....President Bush's State of the Union address Tuesday made no mention of the Vision for Space Exploration or space policy in general.
Avron - 2/2/2006 11:23 PMQuoteLunar Dreamer - 18/1/2006 3:07 PMDon't know about falling apart, but if you read NASAwatch you would think so. It's hardly looking good!Its the design process, it needs time to evolve. The first option selected without detailed analysis beyond conceptual design, is rearly the design that flies. The architecture presented is no more than that, its conceptual in nature. Lets give the design teams the time to do the right selection, then we can watch the fun and games in the downselecting, where the money is at play..
JulesVerneATV - 8/2/2006 7:12 PMQuoteAvron - 2/2/2006 11:23 PMQuoteLunar Dreamer - 18/1/2006 3:07 PMDon't know about falling apart, but if you read NASAwatch you would think so. It's hardly looking good!Its the design process, it needs time to evolve. The first option selected without detailed analysis beyond conceptual design, is rearly the design that flies. The architecture presented is no more than that, its conceptual in nature. Lets give the design teams the time to do the right selection, then we can watch the fun and games in the downselecting, where the money is at play..NASA's "Bizarre" Cutshttp://www.technologyreview.com/BizTech-Manufacturing/wtr_16302,309,p1.htmlThe director of the Planetary Society says the space agency is robbing science missions and manned exploration.
rcaron - 10/4/2006 11:11 PMArgh! I can't believe that they're avoidance of developing methane/lox is going to end up completely destroying the VSE's capability. Can we not develop new technologies when they're warranted (and aren't we going to Mars after this?)The diameter resizing, going J2-S/X instead of air-start SSME, that's all reasonable. But limiting the LSAM to barebone capability (2 crew, equatorial only, short duration) is useless. This isn't supposed to be Apollo!As a aerospace engineering student, I'm slowly seeing a promising future erode away.
rcaron - 10/4/2006 11:11 PMAs a aerospace engineering student, I'm slowly seeing a promising future erode away.
vanilla - 10/4/2006 11:26 PMQuoteJim - 10/4/2006 10:14 PMThe deletion of Methane has nothing to do with the current issues. It is matter of lift capability.On the contrary, it seems that much of the weight growth in the VSE vehicles is due to the shift from methane to hypergols.
Jim - 10/4/2006 10:14 PMThe deletion of Methane has nothing to do with the current issues. It is matter of lift capability.
rcaron - 11/4/2006 12:31 PMThe change to hypergols was also in the Service Module, which was also supposed to me LCH4/LOX. Since this where the TEI burn comes from (i.e. ticket home), there needs to be a lot of dV there and as such the mass penalty obviously isn't trivial.Sending CEV to L2 is just plain silly. In what's proposed now, we're sending two people down in the LSAM while two people remain in CEV. Since L2 is conveniently located behind the moon, that means we'll have some guys out of radio contact for days at a time. A lunar comsat is obviously needed, but with this exploding mass growth where would it fit?
DigitalMan - 11/4/2006 4:36 AMIt is early in the process. Better to be frustrated now than later.
Jim - 11/4/2006 7:37 AMThe change was only in the ascent stage. It went from methane to hypergols. The Descent remains LH2/LO2
kraisee - 11/4/2006 3:40 PMIf LOX/Methane were to be used instead, there is a reduction in mass, but only by about 1/3rd, a total saving of, maybe, 3mT or so.I don't think that's enough of a difference to justify the difficult and costly development of such a propulsion system. We'd have to make a brand-new Methane powered rocket engine suitable for the job, and then go through all the extra hastle of making it man-rated and so completely reliable that it can be used on the CEV as the only get-you-home-or-bust engine.Hypers make more sense to me for the first generation of CEV SM.
I don't know if a halo L2 orbit can be sufficiently large to maintain comms w/ Earth.
kraisee - 12/4/2006 6:51 AMAnyway, they said that there is a group of proponents within NASA who would prefer to start the VSE by just aiming to replicate the Apollo missions, and build towards better things once you've proved those "simple" (!) missions can be done again now. Aparently they are the ones actually responsible for the "Walmart" lander concept.Ross.
abacus - 12/4/2006 9:39 AMQuotekraisee - 12/4/2006 6:51 AMAnyway, they said that there is a group of proponents within NASA who would prefer to start the VSE by just aiming to replicate the Apollo missions, and build towards better things once you've proved those "simple" (!) missions can be done again now. Aparently they are the ones actually responsible for the "Walmart" lander concept.Ross.I see no problem going with the "Walmart" approach initially. The problem seems to be though that the CaLV will not be able to carry anything much better. We can have a simple starting point as long as there is ample room to expand it. That is not what is being proposed - "Walmart" seems to have been proposed because the better alternatives don't work - not just to give the program a simpler start.
MartianBase - 12/4/2006 3:19 AMSometimes I really can't stand the rants of JeffreyBell, he sometimes comes across as anti-NASA, bitter, anti-Shuttle, anti-space you name it...but as much as we love to hate a heretic or anti-space infidel we can't just dismiss Bell outright, at times he comes up with some really good points
MartianBase - 12/4/2006 12:19 PMHere's Bell from Honolulu
Tap-Sa - 16/4/2006 4:22 AMMethane boiling point is 111.5K versus oxygen 90.2K, it would seem that methane is actually easier to keep liquid than LOX. Is this just writer's little slip up or is there some other consideration that changes the picture? I thought methane got axed due to lack of experience on methane engines and developing one would have costed too much.
Tap-Sa - 16/4/2006 4:22 AMI like Bell's proposition of ditching the Stick and going for 2xCaLV. The 'mundane' LEO-ISS flights would be outsourced to EELV+CEV while NASA folks could concentrate their army to work on only one NASA-specific launcher. Even ATK should be happy with this because one moon mission consumes four SRBs instead of three. The CaLV development ought to be a bit cheaper since instead of 100+ ton behemoth it would be 'just' 50-60 ton giant, and it's flight rate would double ie disperse the R&D costs nicely. NASA would need to worry about just one type of pad, buy service from EELV contractors and let them worry about the EELV+CEV pad, they'll probably do required modifications much cheaper.About starting with taking babysteps using Walmart LSAM; that would be OK if it meant also Walmart pricetag. And preferably faster timetable. It should not take more than a decade to repeat what was done in less than a decade forty years ago.
rcaron - 16/4/2006 4:59 AMThe 'mundane' LEO-ISS flights would be outsourced to EELV+CEV while NASA folks could concentrate their army to work on only one NASA-specific launcher. NASA would need to worry about just one type of pad, buy service from EELV contractors and let them worry about the EELV+CEV pad, they'll probably do required modifications much cheaper.At a minnum (Delta IV-Heavy being the closest contender), a new upper stage would be needed. Atlas 5 would have to have 3 parallel cores, closely remembling the Delta IV-Heavy. An "Atlas Phase 2" vehicle is the least complex EELV option, except for the fact that it barely has any heritage with the current Atlas line. As such, NASA can't just hand over CEV/ISS flights to USAF/EELV and have them "take care of it". There'd be a lot of R&D needed to make EELV work for this, and I doubt that there upgrades would be used by anybody but NASA, so they'd have to foot the bill. New stages, new engines, it isn't trivial.
rcaron - 16/4/2006 12:59 PM Crewed flights are past the upper limit of current EELV hardware.
Bring methane back!
Tap-Sa - 16/4/2006 4:22 AMAbout starting with taking babysteps using Walmart LSAM; that would be OK if it meant also Walmart pricetag. And preferably faster timetable. It should not take more than a decade to repeat what was done in less than a decade forty years ago.
Tap-Sa - 16/4/2006 11:08 AMQuotercaron - 16/4/2006 12:59 PM Crewed flights are past the upper limit of current EELV hardware. The Lunar CEV with massive SM yes. But why ESAS quotes ISS Crew CEV about as massive as the lunar version, including 1500+ m/s dv capability is beyond me. Do you really need as big SM to LEO missions as lunar ones??QuoteBring methane back!Hear hear.
Jim - 16/4/2006 8:14 AMThere is an Atlas V Heavy with 3 cores, it was stopped at CDR. Phase 2 Atlas has a lot of heritage with the current line, only structures are different. NASA already buys EELV's and the Air Force is not involved. NASA did all the oversight for the RTG flying on New Horizons. NASA was ready to fly OSP on EELV's and much of the planning including pad mods was completed
rcaron - 16/4/2006 3:59 PMIts too bad we didn't go OSP - I like lifting bodies alot, although optimization-wise they're strictly LEO. I hope the Russian Klipper pans out.
vt_hokie - 16/4/2006 4:04 PMMe too! I also hope that "Blackstar" actually exists, because it would be nice to think that this country can still follow through on something more ambitious than a simple capsule based on the Apollo CM design.
rcaron - 16/4/2006 3:59 PMQuoteJim - 16/4/2006 8:14 AMThere is an Atlas V Heavy with 3 cores, it was stopped at CDR. Phase 2 Atlas has a lot of heritage with the current line, only structures are different. NASA already buys EELV's and the Air Force is not involved. NASA did all the oversight for the RTG flying on New Horizons. NASA was ready to fly OSP on EELV's and much of the planning including pad mods was completedIts too bad we didn't go OSP - I like lifting bodies alot, although optimization-wise they're strictly LEO. I hope the Russian Klipper pans out. But anyways, back to EELV. Delta IV-H is closest to meeting reqs, and at least it flew once (anybody know when the next flight is?) The ISS CEV SM is 6mT lighter than the lunar variant because of the lower propellant, at least in theory. Other charts show the ISS variants weighing as much as lunar, but this is because they use the excess dV capability for better launch abort coverage. IIRC, abort coverage isn't as great going to 51.6 as 28.5, so they needed all the abort dV they could get their hands on. So it doesn't look like the SM is actually offloaded much (if at all) for ISS flights, keeping payload mass above what current EELVs can offer. I'm not so sure the OSP could have flown on the current EELVs either - they're inherently more heavy than capsules, although they're better L/D could lower abort propellant requirements.My apologies about my earlier post concerning the heritage concerning Atlas Phase 2. It just looks nothing like the current Atlas line, and I guess I just balk at changing the vehicle diameter. Structure isn't trivial, and I don't think Atlas facilities are designed to handle such large diameters. If I were to guess, Phase 2 structure & tanks would have to be built at Michoud, making Atlas Phase 2 a hybrid of Shuttle-derivation and EELV. It'd be interesting, and if we were not going to pogo-stick this is the closest thing we have to a "clean sheet" design that is optimized for this mission. But there isn't the money (ESAS says the development cost factor of Phase 2 is 1.79 - by far the highest of the options), and we probably don't have the time either.
rcaron - 16/4/2006 4:12 PMFunny you bring that up. Blackstar has a really high "cool" factor, and it's representative of a lot of capabilities we're still trying to aquire. But I agree with Bell on this one - its just a pipe dream.
Jim - 16/4/2006 4:48 PMThe OSP spacecraft were capsules
Jim - 16/4/2006 4:48 PMAtlas Phase 2 diameter is the same as the current large fairing. Only VIF platforms would need to be modified
vt_hokie - 16/4/2006 6:17 PMQuotercaron - 16/4/2006 4:12 PMFunny you bring that up. Blackstar has a really high "cool" factor, and it's representative of a lot of capabilities we're still trying to aquire. But I agree with Bell on this one - its just a pipe dream. Well, making such a "pipe dream" into reality is the type of thing that made me go into engineering! I'd rather be involved in something like than than in re-creating Apollo using old designs and old hardware.
rcaron - 16/4/2006 8:21 PMThe technology doesn't exist yet to make SSTO or Blackstar actually work - we're always getting closerthough.
rcaron - 16/4/2006 8:08 PMQuoteJim - 16/4/2006 4:48 PMThe OSP spacecraft were capsulesOnly 1 of the 4 big OSP designs was capsule shaped, I refer to this spaceflightnow article. Remember OSP started before Columbia, and back then the idea of going with a capsule design was just silly. Capsule obviously got more traction afterwards, but it was still 50/50 when the OSP program got folded into CEV.QuoteIncorrect, at the end of the OSP program, when it was only LM and Boeing, they were all capsules. I was at the pre SRR. That article was old news when it was published.
spacefire - 16/4/2006 9:35 PMI am surprised that anyone is surprised at how things have turned out.'Vision' was never the first word in VSE.
spacefire - 16/4/2006 10:35 PM...'Vision' was never the first word in VSE.
rcaron - 17/4/2006 2:12 PMWell, am I wrong to think that the majority of current technical problems with VSE stem from the move to hypergolics instead of methane/lox? Everything else seems technically feasible - we need to get cracking at methane engines. IMO, we should give that to NASA Glenn for them to work on now, especially since according to nasawatch they currently aren't getting a lot of relevent work anymore.
rcaron - 17/4/2006 2:12 PMI know the VSE has never been terribly strong politically, but it looks like its been gaining some good traction in the House of Represenatives finally. There has been talk of giving NASA a lot more (like a few billion more) so everything can be worked on w/out cutting science to hell. I think the main proponent of that was DeLay, but there has been support for such an increase from the Democrats too, name just escapes me at the moment.
kraisee - 17/4/2006 2:59 PMThe difference for using Hypergolics instead of Methane/LOX on the CEV Service Module (CEV-SM) and LSAM Ascent Stage (LSAM-AS) is not as big a factor as people think. In the spacecraft system which is going to mass probably 60 tons when it arrives at the moon, we're talking about a difference of just two or three tons. But to get that difference we first would have to spend billions of dollars extra to develop the Methane engines to the point that they are so reliable we'll risk crews lives on them. For every billion we spend on Methane engines, we could use it instead to launch a complete extra mission to the moon.Even if we switch to Methane is will not allow the baseline LSAM as originally planned to fly. Other changes will still be required.There are an awful lot of changes which can be done ahead of Methane, which will result in far greater changes to the mass of the spacecraft at a far lower cost. Those are worthwhile pursuing more aggressively than Methane – and NASA is doing that pursuit right now. The results will eventually be made public and I think we’ll be pleased with those results when we see them.Lets try to remember that there is no Methane on the moon. So we won’t be filling the tanks at the moon – which is the primary reason for having Methane. Methane only comes into its own for Mars missions where we can land a vehicle and refuel it on the surface there, meaning we won’t have to send all that fuel mass to Mars, which makes things much easier. But the Mars program is still probably 20 years away, so we have plenty of time to develop the necessary tech.Ross.
rcaron - 17/4/2006 8:17 PMKraisee, you obviously know more about this than I, but I'm still curious on why the original LSAM as outlined in ESAS can't fly. What wasn't accounted for? I read the report, and while I can't say I agree with all the decisions I thought the analysis was fair and realistic. I mean, what changes are left to make? LOI is LH2/LOX in the LSAM descent stage, supplemental radiation shielding is minimal/nonexistant, avionics will be lighter, and LSAM airlock capability has been minimized to keep the mass down. Other than CEV @ L2, it doesn't look like things are going to get much lighter. But you say there are changes in the works, and as always I early await to hear them.
What I'm not pleased to hear is that some of the changes are being made "in the dark". Maybe I'm just an idealist (and a very curious aerospace-engineer-in-training), but NASA is civilian and their work should be open. So the process isnt dressed up in a nice & pretty PR package. So what? NASA is an technical agency, and we should expect and promote seeing the process as it happens. /end rant.
Hotol - 18/4/2006 11:30 AMI second that. I was half expecting you to attack Jeff Bell over his follow up where he refused to believe it was inaccurate.
Doug Stanley - 26/4/2006 9:27 AMEveryone take a deep breath, the sky is not falling! The NASA VSE architecture is not "broken" in any significant way.
Delta Manager - 26/4/2006 10:26 AMQuoteDoug Stanley - 26/4/2006 9:27 AMEveryone take a deep breath, the sky is not falling! The NASA VSE architecture is not "broken" in any significant way. I'm not sure if you are fluent with this site's forum, but you might find this section more interesting by way of questions being posed on why a large amount of people have concerns.http://forum.nasaspaceflight.com/category-view.asp?catlock=3
Chris Bergin - 26/4/2006 11:18 AMThat'd be helpful, especially when it'll keep everything in one place. I'll set that up today, link up the previous Q and A thread (to avoid - hopefully - repeat questions) and it should be ready for you to trawl through once you've returned from vacation.