Which CLV is most likely to actually fly a crew? Ares I? D-IVH? Atlas V-H? Jupiter 120? Saturn IB? Rocketship X-M?(Note that this is not a choice which CLV option you prefer, just the one most likely to actually become operational)Simon
Delta IV Heavy.
ISS: Ares ILunar: Something similar to Jupiter-246
Quote from: marsavian on 04/25/2009 08:02 pmDelta IV Heavy.I agree -- Delta IV Heavy. I think the only hope for Ares I is if the new administrator chooses to close his/her eyes to cost and schedule just to say he/she built a new rocket.Danny Deger
Quote from: Danny Dot on 04/25/2009 08:05 pmQuote from: marsavian on 04/25/2009 08:02 pmDelta IV Heavy.I agree -- Delta IV Heavy. I think the only hope for Ares I is if the new administrator chooses to close his/her eyes to cost and schedule just to say he/she built a new rocket.Danny DegerIf it's Lori Garver that just won't happen as the transition team questions were already signifying a loss of patience with Ares I and more interest in EELVs.
... I agree that the DIVH to ISS is the most likely CLV for ISS missions. ...
Quote from: Mark S on 04/25/2009 08:29 pm... I agree that the DIVH to ISS is the most likely CLV for ISS missions. ...Atlas V Heavy has been show repeatedly, both by NASA and by the recent independent Aerospace Corp study, to be a lower cost, better performing option than Delta IV Heavy. If not Ares I, why would NASA pick the worst of two EELV choices? - Ed Kyle
Atlas V Heavy has been show repeatedly, both by NASA and by the recent independent Aerospace Corp study, to be a lower cost, better performing option than Delta IV Heavy. If not Ares I, why would NASA pick the worst of two EELV choices?
Quote from: edkyle99 on 04/25/2009 08:39 pmQuote from: Mark S on 04/25/2009 08:29 pm... I agree that the DIVH to ISS is the most likely CLV for ISS missions. ...Atlas V Heavy has been show repeatedly, both by NASA and by the recent independent Aerospace Corp study, to be a lower cost, better performing option than Delta IV Heavy. If not Ares I, why would NASA pick the worst of two EELV choices? - Ed KyleTwo reasons. The Atlas uses Russian engines and the Atlas Heavy hasn't flown yet and is currently not under development.Danny Deger
snipIf Ares I is so awful on cost and performance, then those opposed to Ares I cannot defend Delta IV over Atlas V on either count. - Ed Kyle
Obviously Ares-I is currently the 'chosen one', like it or not.However if there is a major shift in policy, I reckon we could see a stripped down Orion with most of its propellant offloaded flying on an Atlas 402. If we need a cheaper faster way of launching Orion, might as well do it really cheap whilst attaining the best safety possible in the circumstances. YMMV.
Quote from: Kaputnik on 04/25/2009 10:08 pmObviously Ares-I is currently the 'chosen one', like it or not.However if there is a major shift in policy, I reckon we could see a stripped down Orion with most of its propellant offloaded flying on an Atlas 402. If we need a cheaper faster way of launching Orion, might as well do it really cheap whilst attaining the best safety possible in the circumstances. YMMV.I think it would have to be the Atlas 552 as you can only get rid of 6300Kg by off loading fuel since at least 2000Kg of propellant probably needs to remain so it can reach ISS and deorbit.Even if you launched it with no propellant it still would be several tons too heavy for the 402.Other things such as the LAS, and boost cover have to stay in place. An an Orion with an LAS on 552 is going to be a safer vehicle then one with no LAS on 402.
There is a lot of work to do to get Atlas-VH operational, not least of which is to do all the development work to create the outboard boosters and get the flight dynamics sorted out.
Two reasons. The Atlas uses Russian engines
I say Delta IV-H is most likely because Atlas V-H has not flown and the Delta can be ready sooner.Atlas V would likely have lower reoccurring costs but it's lead time would be longer.Plus P&W will need time to tool up engine production the foreign engine is an issue that would need to be solved.Besides P&W probably can scare up a little more performance out of the RD-180 or give it a better health monitoring system as well increase it's safety margins.
Quote from: Danny Dot on 04/25/2009 09:34 pmTwo reasons. The Atlas uses Russian engines Not a issue. Astronauts fly on Russian Soyuz
Delta won't ready earlier. Pad mods will take longerAtlas lead time isn't longer. Its avionics are nearly redundant and
Who says domestic RD-180 production is require? Domestic Soyuz production isn't required.
No, there isn't. Atlas V Heavy has already gone through CDR. Only thing needed is GSE mods and productions mods. The drawings and analysis are 90% done (Definition of CDR)
QuoteNo, there isn't. Atlas V Heavy has already gone through CDR. Only thing needed is GSE mods and productions mods. The drawings and analysis are 90% done (Definition of CDR)No matter how you spin it a paper configuration is just that a paper configuration. Until it gets tooled up for production and flies or at least gets some hold down tests for the first time it's an unknown and is no more real then Ares I or F9-H.
Which CLV is most likely to actually fly a crew?
Quote from: Mark S on 04/25/2009 08:29 pm... I agree that the DIVH to ISS is the most likely CLV for ISS missions. ...Atlas V Heavy has been show repeatedly, both by NASA and by the recent independent Aerospace Corp study, to be a lower cost, better performing option than Delta IV Heavy. If not Ares I, why would NASA pick the worst of two EELV choices?
1. Nearly is not good enough it has to be fully redundant with safe failure modes or no dice.2. Both LVs are going to require a lot of pad modifications the Launch Complex 41 launch pad is pretty much going to need a new tower or at least the addition of a mobile gantry system complete with an elevator and escape system.3. The preferred solution would be to be able to have a catwalk able to swing in for the crew to egress at all times.4. The big issue is the fact NRO is using Atlas for most missions and would not like to see their operations delayed 12 to 18 months while the pad is reworked.5. As for domestic production I think a lot of congressmen might have some dispute with that.Plus there's the pride factor which is more important then you think in gathering political support from the public6. No matter how you spin it a paper configuration is just that a paper configuration.7. Until it gets tooled up for production and flies or at least gets some hold down tests for the first time it's an unknown and is no more real then Ares I or F9-H.8. Atlas V-H will be very lucky to have such a minor and easily fixed issue on it's first flight.
Quote from: edkyle99 on 04/25/2009 08:39 pmQuote from: Mark S on 04/25/2009 08:29 pm... I agree that the DIVH to ISS is the most likely CLV for ISS missions. ...Atlas V Heavy has been show repeatedly, both by NASA and by the recent independent Aerospace Corp study, to be a lower cost, better performing option than Delta IV Heavy. If not Ares I, why would NASA pick the worst of two EELV choices?When last time NASA chose a lower cost, better performing option? I can't remember this ever happening. If such a thing ever happened, it was before Saturn V days.
5. Not so, we are already flying our astronauts on Soyuz, they aren't complaining about that. An engine is minor compared to that
snip1. No dice? You don't know enough to say that. Where is the requirement that it has to be fully redundant? Where is your data for that? Anyways, Atlas is only missing one box that doesn't have redundancy and the new version has gone through CDR. D-IV is no where near redundant.snip5. Not so, we are already flying our astronauts on Soyuz, they aren't complaining about that. An engine is minor compared to thatsnip
To be fair, we aren't flying our astronauts on Soyuz as the primary, much less sole, method of getting them to ISS. Though, as long as we ramp up domestic RD-180 at some point, I don't think it will shift the cards in favor of Delta IV.
Can you post a link to the latest NASA man rating requirement document stating single fault tolerant is no longer a requirement? The latest I can find states it is still a requirement. Here is a quote from the May 2008 version:3.2.2 The space system shall provide failure tolerance to catastrophic events (minimum of one failure tolerant), Is there a later version where a "minimum of one failure tolerant" is not required?
Quote from: strangequark on 04/26/2009 03:02 pmTo be fair, we aren't flying our astronauts on Soyuz as the primary, much less sole, method of getting them to ISS. Though, as long as we ramp up domestic RD-180 at some point, I don't think it will shift the cards in favor of Delta IV.We will during the gap. NASA just sent out a solicitation for Soyuz rides
Quote from: Danny Dot on 04/26/2009 03:07 pmCan you post a link to the latest NASA man rating requirement document stating single fault tolerant is no longer a requirement? The latest I can find states it is still a requirement. Here is a quote from the May 2008 version:3.2.2 The space system shall provide failure tolerance to catastrophic events (minimum of one failure tolerant), Is there a later version where a "minimum of one failure tolerant" is not required?Redundancy is method of meeting fault tolerance, it isn't a requirement in itself
Quote from: Jim on 04/26/2009 03:10 pmQuote from: Danny Dot on 04/26/2009 03:07 pmCan you post a link to the latest NASA man rating requirement document stating single fault tolerant is no longer a requirement? The latest I can find states it is still a requirement. Here is a quote from the May 2008 version:3.2.2 The space system shall provide failure tolerance to catastrophic events (minimum of one failure tolerant), Is there a later version where a "minimum of one failure tolerant" is not required?Redundancy is method of meeting fault tolerance, it isn't a requirement in itselfDo you agree this requirement for "minimum of one failure tolerant" is the current requirement?Danny Deger
We will during the gap. NASA just sent out a solicitation for Soyuz rides
Delta IV-H keeps getting mentioned because, well, it's actually flown. If it pulled the Ares I "SM as a third stage" trick, a current Delta IV-H could probably work for ISS/LEO. With planned (and IIRC, already funded) upgrades it could handily do Lunar Orion. So, it's understandably the most mentioned second choice.Simon
Quote from: Jim on 04/26/2009 03:07 pmQuote from: strangequark on 04/26/2009 03:02 pmTo be fair, we aren't flying our astronauts on Soyuz as the primary, much less sole, method of getting them to ISS. Though, as long as we ramp up domestic RD-180 at some point, I don't think it will shift the cards in favor of Delta IV.We will during the gap. NASA just sent out a solicitation for Soyuz ridesAnd they just dropped the minimum number of seats from 18 to 3. Something is afoot to not buy as many seats from Russia. Does KSC know something about the Delta we don't know?
The real question with Delta IV-H is how to transition from LEO to the point of the VSE, exploration. If Delta IV-H were to be chosen to fly Orion, then the eventual lunar vehicle(s) would most likely use RS-68Bs, but not necessarily SRBs...Simon
Quote from: Danny Dot on 04/26/2009 03:12 pmQuote from: Jim on 04/26/2009 03:07 pmQuote from: strangequark on 04/26/2009 03:02 pmTo be fair, we aren't flying our astronauts on Soyuz as the primary, much less sole, method of getting them to ISS. Though, as long as we ramp up domestic RD-180 at some point, I don't think it will shift the cards in favor of Delta IV.We will during the gap. NASA just sent out a solicitation for Soyuz ridesAnd they just dropped the minimum number of seats from 18 to 3. Something is afoot to not buy as many seats from Russia. Does KSC know something about the Delta we don't know?I doubt the change in the Soyuz solicitation had anything to do with Delta. The change notice specifically mentioned commercial providers (e.g. SpaceX).
err, wouldn't a ULA Delta based system qualify as commercial?
ULA doesn't have a spacecraft
Quote from: Jim on 04/26/2009 05:45 pmULA doesn't have a spacecraftThis will probably annoy Jim (it usually does when I start weaving 'what if...?' scenarios with ULA) but I have to ask.I know that Lockheed-Martin was co-operating with SpaceDev with on their DreamChaser space-plane. Does anyone know what is the current status of those interactions? I must say that I haven't seen any updates recently.Just look at what these arrangements potentially gives them:1) Atlas-V - Flexible ELV; I'm sure Boeing wouldn't begrudge them a Delta-IV if they asked either;2) DreamChaser - Essentially COTS-D-ready crew vehicle;I'm not saying that they are planning anything right now. However, if CxP crashes and burns, there is a nice big gap into which they (through the offices of ULA) could jump, if they have done their prepartory work correctly and can get moving quickly enough.Don't forget that Lockheed have the Centaur (single and twin-engine variants) that is a good EDS. They also did some work on various lander concepts. Don't forget that they have also been talking to Bigelow, giving them access, if required, to a long-duration, large-capacity crew vehicle. If MSFC completely drops the ball, they have the chance to 'save' the US manned space program.
This will probably annoy Jim (it usually does when I start weaving 'what if...?' scenarios with ULA) but I have to ask.A. I know that Lockheed-Martin was co-operating with SpaceDev with on their DreamChaser space-plane. Does anyone know what is the current status of those interactions? I must say that I haven't seen any updates recently.Just look at what these arrangements potentially gives them:B. 1) Atlas-V - Flexible ELV; I'm sure Boeing wouldn't begrudge them a Delta-IV if they asked either;2) DreamChaser - Essentially COTS-D-ready crew vehicle;
According to Chris's story, Atlas V would still cost less than Delta IV, because the new Delta IV pad needed would cost twice as much as the Atlas V pad modifications, and because man-rating the Delta IV would cost twice as much as man-rating Atlas V.http://www.nasaspaceflight.com/2009/04/study-eelv-capable-orion-role-griffin-claims-alternatives-fiction/If Ares I is so awful on cost and performance, then those opposed to Ares I cannot defend Delta IV over Atlas V on either count. - Ed Kyle
Dragon on a Falcon 9.
Well if all goes well, we’ll see an unmanned Dragon fly on a Falcon 9 later this year.
Is there a sense here (I'm careful not to call it a consensus) that, in the absence of political and institutional forces, an RP-1 first stage would be preferable to an all-LH2 launch vehicle?
I don't understand all this 'sending money to Russia' angle. We (the US) send over $270 Billion as our trade deficit to China (probably towards their own chinese space program). Surely it dwarfs any Soyuz purhcase.
Bit late to the pertinent discussion:NASA already uses the Atlas V, and therefore the foreign made RD-180, in previous and upcoming science missions. There is:1. No demand for the Americanization of production of that engine.2. No selection of the Delta 4 instead of the Atlas V.Actual NASA behavior when faced with this choice is in direct contravention to the theory that NASA would reject the Atlas V due to nationalistic concerns over the engine source.
Of course, this simply feeds into my argument that if (and please notice that modifier - it is critical) they have some kind of crew vehicle in the works (thank you SpaceDev) ULA could make a bid for COTS-D.
Actually, that is very interesting. I didn't realise that the element of LM that handled Atlas was now considered to be ULA. Of course, this simply feeds into my argument that if (and please notice that modifier - it is critical) they have some kind of crew vehicle in the works (thank you SpaceDev) ULA could make a bid for COTS-D.
Quote from: veryrelaxed on 04/27/2009 05:33 amI don't understand all this 'sending money to Russia' angle. We (the US) send over $270 Billion as our trade deficit to China (probably towards their own chinese space program). Surely it dwarfs any Soyuz purhcase.The big difference is tax money vs. personal money.But I agree with you, why the heck are we so strict regarding ITAR when we are essentially paying China to develop an indigenous space program and military?
Upthread people were saying that the Delta IV Heavy could loft an Orion capsuke to the ISS but not a lunar able Orion to the LSAM+EDS stack. But I thought DIVH could lift 25 mT to LEO and that Lunar Orion was set at 20-21 mT. Elsewhere on this site people have said that ULA had developed a blackzone-free launch profile and that it did not affect lift capacity. One or more of the statements is false, but I don't know which?
HOW MANY TIMES DO WE HAVE TO SAY IT??? ULA AS A PRIME CANNOT BID ON ANYTHING BUT GOVERNMENT LAUNCHES. IT CANNOT BID ON COMMERCIAL LAUNCHES. IT CANNOT BID ASA A PRIME ON GOVERNMENT OR COMMERCIAL PAYLOADS. It would have to be a sub on COTS-D. This is all due to the DoD and FTC consent decrees that allowed the formation of ULA to mitigate concerns by satellite companies. If you learn one old thing on NSF this week, make it this.
If NASA pays attention to people who know EELV: Atlas V Heavy.
Yes.Didn't mean my tirade specifically at you, Norm. Many folks have that misimpression and I'm tired of correcting it.
What's wrong with the Atlas 552 for ISS missions?
Keep in mind that the crew launch vehicle doesn't just launch the Orion CM and SM, but also must lift the heavy LAS and fly a more constrained ascent profile, which cuts payload capability compared to the standard satellite launch numbers.
Quote from: Cons on 04/27/2009 05:18 pmWhat's wrong with the Atlas 552 for ISS missions?If NASA intends to go to the Moon someday, it needs to develop a Crew Launch Vehicle that can do the job. Atlas 552 isn't that launch vehicle.
'Human rating' a design with five solids? I doubt there is any statistically significantdifference in LOM numbers between the Heavy and the 552.
Quote from: Cons on 04/27/2009 05:18 pmWhat's wrong with the Atlas 552 for ISS missions?If NASA intends to go to the Moon someday, it needs to develop a Crew Launch Vehicle that can do the job. Atlas 552 isn't that launch vehicle. - Ed Kyle
Again, Atlas Heavy is a really nice rocket, but it just ain't likely to happen. NASA would _only_ go with an EELV if they wouldn't have to spend even more development money, and that means Delta. ULA management would favor Delta too, as they don't have to do anything different than increase Delta IV core production.
Again, Atlas Heavy is a really nice rocket, but it just ain't likely to happen. NASA would _only_ go with an EELV if they wouldn't have to spend even more development money, and that means Delta. ULA management would favor Delta too, as they don't have to do anything different than increase Delta IV core production.If not Ares I, and not Delta IV-H, then Atlas Phase II (or similar) becomes likely, skipping Atlas V Heavy entirely.Simon
. . . it might start looking like a good option to use the TR-107 just to get a higher thrust main engine for the 5M CCB which would also solve the Russian engine issue.I don't really like relying on imported engines due to the need to preserve the skill base and train new engineers to design and produce new engines inside the US.
1. Go strait to Atlas phase II it might start looking like a good option to use the TR-107 just to get a higher thrust main engine for the 5M CCB which would also solve the Russian engine issue.2. I don't really like relying on imported engines due to the need to preserve the skill base and train new engineers to design and produce new engines inside the US.3. I know it will impact pad operations but they would already be impacted by the phase II modifications plus NASA would likely convert a pad such as complex 34 4. which already was considered for reactivation for Ares I vs use the normal ULA ones for their manned program.5, Besides I'm sure the unmanned guys and NRO don't want operations at the the existing sites disrupted while all the stuff to support human space flight are added to the existing facilities.6. This probably would disrupt operations far worse then something like a new engine when you look at what they're doing to pad 39B.
Most likely: Delta-IV Heavy.Second most likely: Jupiter-130 (or similar).Ross.
Prove that Delta is less expensive than Atlas.Prove that ULA management favors Delta.
Don't say things you can't prove.
Go strait to Atlas phase II it might start looking like a good option to use the TR-107 just to get a higher thrust main engine for the 5M CCB which would also solve the Russian engine issue.
That picture so sexy! Thanks!
Quote from: Norm Hartnett on 04/29/2009 06:05 pmThat picture so sexy! Thanks!While sexy, it does absolutely nothing to "prove" the points Antares raised.
Actually it does, sort of. There are "reliable" figures on Delta IVH costs. Since the Atlas VH has not been built or flown there aren't as good a figure for them.
Quote from: Patchouli on 04/28/2009 04:08 amGo strait to Atlas phase II it might start looking like a good option to use the TR-107 just to get a higher thrust main engine for the 5M CCB which would also solve the Russian engine issue.If you go clean-sheet, Atlas Phase II looks good, but a entirely new engine development program would be a time/budget killer. Take all the headaches from J-2X and multiply them by two because of the even less schedule to work with...Now, an Atlas Phase II-sized vehicle with a J-2X upper stage (already paid for, might as well use) and either RS-25 or RS-68 first stage sounds just as, if not more, likely...Simon
Simon, I'll put my prima facie credibility on this board up against yours any time.Your post did nothing to prove which was cheaper and which was favored. I could prove one and infer the other, but I'd have to use data that doesn't belong to me (public data isn't accurate enough in this case). You don't have access to that data and couldn't post it either for the same reason. Ergo, you can't prove either of the things I asked you to. You should not post about things you can't prove. QED.
Quote from: Antares on 04/29/2009 10:16 pmSimon, I'll put my prima facie credibility on this board up against yours any time.Your post did nothing to prove which was cheaper and which was favored. I could prove one and infer the other, but I'd have to use data that doesn't belong to me (public data isn't accurate enough in this case). You don't have access to that data and couldn't post it either for the same reason. Ergo, you can't prove either of the things I asked you to. You should not post about things you can't prove. QED.I think a fast tracked study needs to be done before an EELV can be chosen this is not the type of decision that can be made without one.Many factors such as lead time,cost,pad operations and commonality with the HLV need to be considered.The first CLV will likely be a short lifespan program quickly replaced by a derivative of the HLV or other vehicle as requirements evolve.It won't be like Soyuz essentially unchanged for forty years.
Atlas V is (sorry you'll have to take my word for it, corroborated by other folks in the know on here) cheaper and has greater margins of safety. The launch vehicle is not the critical path here. AVH can finish development ahead of the time a crew-capable spacecraft is ready.
If NASA goes down the EELV route, would it make sense to pay for the mods for both Atlas and Delta? This is a higher upfront cost, but gives choice, resilience and competition downstream.The cost of modifying both is insignificant to the cost of completing Ares I,
Mods are part of the heavy design, IIRC. They had some alternate solutions as well during OSP that could yield mass savings but are less mature.
But once the EELV is chosen, be ready to accept the fact that no astronauts are going to the moon.
I don't think so. As discussed in Chris's article, it would take more than a billion dollars per vehicle, at least, or multiple billions per vehicle according to NASA. (The truth will probably end up being bigger than the $1 billion value.)
Can anyone out there provide any info on the status of Centaur structure to carry Orion to LEO?Danny
Quote from: Danny Dot on 04/30/2009 01:40 pmCan anyone out there provide any info on the status of Centaur structure to carry Orion to LEO?Danny There is no status since Atlas is not under contract for Orion
Quote from: Jim on 04/30/2009 01:56 pmQuote from: Danny Dot on 04/30/2009 01:40 pmCan anyone out there provide any info on the status of Centaur structure to carry Orion to LEO?Danny There is no status since Atlas is not under contract for OrionHow about this? Is the current Centaur strong enough to do the job with a reasonable safety factor?Danny Deger
Quote from: edkyle99 on 04/30/2009 01:26 pmI don't think so. As discussed in Chris's article, it would take more than a billion dollars per vehicle, at least, or multiple billions per vehicle according to NASA. (The truth will probably end up being bigger than the $1 billion value.) The truth is that it will be less than a billion for both (excluding new launch pads or pad mods)
The truth is that it will be less than a billion for both (excluding new launch pads or pad mods)
If it needs another Pad, I've seen figures from $1 billion to $3 billion depending on where it were to be located, and those options were LC-37A, LC-40 (before Space-X took it) and LC-39 using a customized MLP. What surprised me most is that this summary indicated that LC-39 would actually be the cheaper option of those three.The conclusion was that we're only talking about two flights per year to ISS anyway, so we should integrate it into the existing facilities at LC-37B.Ross.
ELV use 1.25fs
Quote from: Danny Dot on 04/30/2009 02:05 pmQuote from: Jim on 04/30/2009 01:56 pmQuote from: Danny Dot on 04/30/2009 01:40 pmCan anyone out there provide any info on the status of Centaur structure to carry Orion to LEO? Danny There is no status since Atlas is not under contract for OrionHow about this? Is the current Centaur strong enough to do the job with a reasonable safety factor? Danny DegerELV use 1.25fs
Quote from: Jim on 04/30/2009 01:56 pmQuote from: Danny Dot on 04/30/2009 01:40 pmCan anyone out there provide any info on the status of Centaur structure to carry Orion to LEO? Danny There is no status since Atlas is not under contract for OrionHow about this? Is the current Centaur strong enough to do the job with a reasonable safety factor? Danny Deger
Quote from: Danny Dot on 04/30/2009 01:40 pmCan anyone out there provide any info on the status of Centaur structure to carry Orion to LEO? Danny There is no status since Atlas is not under contract for Orion
Can anyone out there provide any info on the status of Centaur structure to carry Orion to LEO? Danny
Quote from: alexterrell on 04/30/2009 11:24 amIf NASA goes down the EELV route, would it make sense to pay for the mods for both Atlas and Delta? This is a higher upfront cost, but gives choice, resilience and competition downstream.The cost of modifying both is insignificant to the cost of completing Ares I, I don't think so. As discussed in Chris's article, it would take more than a billion dollars per vehicle, at least, or multiple billions per vehicle according to NASA. (The truth will probably end up being bigger than the $1 billion value.) NASA has its hands full trying to get one crew launch vehicle running. Don't give it two to struggle with. Pick one, whichever is safest or whichever is the best buy, and go with it.
Would Delta's upper stage be more up to the task?
For a long time now, ULA has been looking at building a new common Advanced Upper Stage to use on both Delta and Atlas. I don't think the effort is very far down the path yet, but it would seem like a very logical option for a crew configuration to consider.In the short term I would say there is valid rationale to saying that the DHCUS and Centaur-V1 are both flight-certified and both have safe proven flight histories under their belts, so while we wait for the new advanced upper stage, we could make the deliberate choice to use the current stages *unchanged* (except a health monitoring system for the engines) under a completel routine waiver -- at least for the first six missions or so -- which should be sufficient to cover all flights from thru ~2016.NASA's human rating specifications explicitly allow for precisely this sort of use of the waiver system for exactly this sort of flight hardware which has already been proven to work elsewhere.Ross.
Ares I is currently budgeted at $11 billion to IOC, of which a bit less than $3 billion has been spent. Once operational, it's budgeted at $1.3 billion a year for two flights.If EELV costs $2 billion to human rate, that still saves $7 billion to IOC, which would then be available to cover Orion budget overruns, possibly accelerate Orion, and start work on Ares V and Altair.
The conclusion was that we're only talking about two flights per year to ISS anyway, so we should integrate it into the existing facilities at LC-37B.Ross.
I don't believe in Frankenrockets for a project like this, so I don't have an answer.
If it uses EELV for Orion, then where will J-2X, or equivalent, etc., come from?
Quote from: kraisee on 04/30/2009 02:14 pmThe conclusion was that we're only talking about two flights per year to ISS anyway, so we should integrate it into the existing facilities at LC-37B.Ross.I've long thought that NASA should "get" one EELV, and the Pentagon the other. I suspect that DoD would find a way to "give up" SLC 37 to NASA if it got Atlas V Heavy in return. - Ed Kyle
Quote from: yinzer on 04/30/2009 06:57 pmAres I is currently budgeted at $11 billion to IOC, of which a bit less than $3 billion has been spent. Once operational, it's budgeted at $1.3 billion a year for two flights.If EELV costs $2 billion to human rate, that still saves $7 billion to IOC, which would then be available to cover Orion budget overruns, possibly accelerate Orion, and start work on Ares V and Altair.Remember that the Ares I development cost includes J-2X, which is essential for EDS (cost of which includes the new vacuum test stand at Stennis, etc.). It also includes avionics that would likely be reapplied for Ares V, as well as funding for five segment booster, which supports the infrastructure needed for the Ares V boosters, etc. If NASA is going to the Moon, it is going to need these items, or else it will need to develop hardware that does the same job at great expense. If it uses EELV for Orion, then where will J-2X, or equivalent, etc., come from?
Using EELV for Orion to LEO lets J-2X and 5-segment SRB development proceed in parallel with the development of the EDS, Ares V, and Altair. Using Ares I means that development has to proceed in series.
Quote from: edkyle99 on 04/30/2009 09:39 pmQuote from: kraisee on 04/30/2009 02:14 pmThe conclusion was that we're only talking about two flights per year to ISS anyway, so we should integrate it into the existing facilities at LC-37B.Ross.I've long thought that NASA should "get" one EELV, and the Pentagon the other. I suspect that DoD would find a way to "give up" SLC 37 to NASA if it got Atlas V Heavy in return. - Ed KyleNo, because the DIV Heavy on the west coast is the DOD's
I don't see it myself. If NASA can't afford to develop Ares I/Orion, I don't see how it can afford to develop EELV/Orion, J-2X, 5.5 segment SRB, EDS, Ares V, and Altair all at the same time.
Remember that the Ares I development cost includes J-2X, which is essential for EDS (cost of which includes the new vacuum test stand at Stennis, etc.). It also includes avionics that would likely be reapplied for Ares V, as well as funding for five segment booster, which supports the infrastructure needed for the Ares V boosters, etc. If NASA is going to the Moon, it is going to need these items, or else it will need to develop hardware that does the same job at great expense. If it uses EELV for Orion, then where will J-2X, or equivalent, etc., come from?
The J-2X is less of a need and more of a want. You can cluster RL-10's and get the thrust and ISP you need for an EDS like upper stage. Yes introducing more engines may introduce more failure modes, but the RL-10 is a very mature design, so that's going to offset some of the risk.
It takes a dozen RL10s to produce the thrust of one J-2X. No U.S. launch vehicle has ever fired a 12 liquid engine cluster at this thrust level. Heck, it would be a challenge to *fit* 12 RL10 engines inside a 10 meter diameter interstage (while providing room for nozzle extension and thrust vectoring, etc.).
Quote from: edkyle99 on 05/01/2009 10:19 pmIt takes a dozen RL10s to produce the thrust of one J-2X. No U.S. launch vehicle has ever fired a 12 liquid engine cluster at this thrust level. Heck, it would be a challenge to *fit* 12 RL10 engines inside a 10 meter diameter interstage (while providing room for nozzle extension and thrust vectoring, etc.).Why do you insist on having the thrust of a J-2X?
Quote from: mmeijeri on 05/01/2009 10:21 pmWhy do you insist on having the thrust of a J-2X?That's what it takes to boost the Ares V EDS into orbit.
Why do you insist on having the thrust of a J-2X?
If NASA can't afford to develop Ares I/Orion, I don't see how it can afford to develop EELV/Orion, J-2X, 5.5 segment SRB, EDS, Ares V, and Altair all at the same time.
Potentially daft idea off the top of my head:Take a Delta IVH a replace the core's RS68 with an SSME. Don't bother with an upper stage. For thrust/weight reasons you'd probably need RS68As but the idea is that after booster sep the core functions as the upper stage itself, since it would still have two thirds or more of its propellant load and a high-isp engine.I'm sure it's unrealistic but I'd be curious if such a configuration had ever been studied.
I don't really feel qualified to analyse the concept like that, and I certinaly wouldn't be able to optimise the settings. However I'll have a go using CEPE if that's appropriate?
Now I don't know the good & bad of these things, but if the main core was SSME & the outer engines remained RS-68/RS-68A, does that gain an advantage?
Quote from: robertross on 05/03/2009 01:31 pmNow I don't know the good & bad of these things, but if the main core was SSME & the outer engines remained RS-68/RS-68A, does that gain an advantage?I've read that this is very difficult due to vibration issues: each engine can deal with its own vibrations, but with different kinds of engines you can get resonances that will destroy your engines. Its apparently very difficult to fix this.
The SSME allows you to delete the upper stage entirely. The RS68 is sea-level optimised so you'd have to modify the core's engine to make the core replace the upper stage in the way that the SSME allows.I posted this assuming that either a) it had been considered before; or b) there was some glaring flaw that I'd overlooked. I'm surprised it's generated any interest!I could see the advantages being that it's all-liquid and has all engine ground-started. It could even be quite cost effective because compared to the usual EELV options you've completely removed a stage.
Yeah, I thought it worked too! Sweet.I wonder what's cheaper- a SSME or an RS68+DHCSS?
Assuming I did my CEPE math right, if you take the existing Delta IV Heavy (current RS-68s), replace the core stage's RS-68 with a current SSME, and delete the upper stage, you could inject a 20.5mT crew vehicle with a 7mT LAS into a 51.6deg/407km/407km orbit.Of course, it's always easier in CEPE that it is in the real world.