Quote from: 93143 on 03/16/2013 10:15 pmQuote from: JohnFornaro on 03/14/2013 12:37 pmBlock 1 + SLS, without DSH, and no SLS updates needed. Is HLR feasible? Yes.Dubious. Remember, all you've got is a system capable of putting...... some stuff up there, when what is needed is a lot of stuff.
Quote from: JohnFornaro on 03/14/2013 12:37 pmBlock 1 + SLS, without DSH, and no SLS updates needed. Is HLR feasible? Yes.Dubious. Remember, all you've got is a system capable of putting...
Block 1 + SLS, without DSH, and no SLS updates needed. Is HLR feasible? Yes.
Quote from: 93143So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO. According to page 12, you can't do that...Huh? In my world, the ICPS is designed to support this lunar mission when placed on top of the 70ton SLS. If it is currently incapable of doing this, and it can't be changed since it is already designed and built, then clearly, in my world, there is little intention for mission accomplishment. The lunar mission should not be held hostage by the current "model" of ICPS.
So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO. According to page 12, you can't do that...
it's not the case that a monster SLS is likely to be cheaper than a "small" SLS which more than triples the throw weight of shuttle.
Of course there would be more than one launch of a fully functioning 70ton capable SLS, with LEO assembly of the necessary pieces for a lunar landing.
Also, where does page 12 say that "youcan't do that"? 'Cause the "takeaway" is that there is a "sizeable solution space for a 2 stage lander", that exists within the "SLS Block 1+" capability.
It is my understanding that the boosters and the upper stage are the only components NASA currently seems to want to upgrade. Upper stage first, boosters later. The core stays the same.
Quote from: JohnFornaro on 03/17/2013 03:12 pmQuote from: 93143 on 03/16/2013 10:15 pmQuote from: JohnFornaro on 03/14/2013 12:37 pmBlock 1 + SLS, without DSH, and no SLS updates needed. Is HLR feasible? Yes.Dubious. Remember, all you've got is a system capable of putting...... some stuff up there, when what is needed is a lot of stuff.1) Not what I said. I was referring to the fact that while SLS Block 1's LEO payload is quite large, its upper stage is too small to take full advantage of this fact.2) Block 1 could easily heave an ICPS plus 60 tonnes of payload into LEO, but an ICPS is utterly incapable of getting 60 tonnes of payload anywhere near translunar departure velocity.QuoteQuote from: 93143So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO. According to page 12, you can't do that...Huh? In my world, the ICPS is designed to support this [Edoit: multi-launch, with LEO assembly] lunar mission when placed on top of the 70ton SLS. If it is currently incapable of doing this, and it can't be changed since it is already designed and built, then clearly, in my world, there is little intention for mission accomplishment. The lunar mission should not be held hostage by the current "model" of ICPS.3) The Interim Cryogenic Propulsion Stage is just a 5-metre Delta IV upper stage with a slight hydrogen tank stretch, maybe a bit of structural strengthening and some avionics mods. It's a quick-and-dirty hack. The cost of the whole program including flight units is in the low nine figures; peanuts compared to a real new upper stage.The real SLS upper stage is the CPS, which is an all-new stage capable of properly leveraging SLS' enormous LEO capability. Take an SLS Block 1, stick a CPS on top instead of an ICPS, and you have an SLS Block 1B, which is eminently capable of supporting a manned lunar return even without propellant depots.Quoteit's not the case that a monster SLS is likely to be cheaper than a "small" SLS which more than triples the throw weight of shuttle.4) Ironically, it could well be. The larger, more capable CPS should be a bit more expensive than the ICPS, but the advanced boosters are supposed to be significantly cheaper, and if they save enough money the whole stack could be cheaper. It certainly wouldn't be 'monstrously' expensive, and it's not design bloat - it's just a question of optimizing the stack we've got.It is my understanding that the boosters and the upper stage are the only components NASA currently seems to want to upgrade. Upper stage first, boosters later. The core stays the same.QuoteOf course there would be more than one launch of a fully functioning 70ton capable SLS, with LEO assembly of the necessary pieces for a lunar landing.5) "Of course"? That doesn't follow at all. If the only existing EDS is too small for a single launch, and lacks any real loiter capability, what does LEO assembly buy you? You'd have to develop a new EDS anyway, and once you've done that, you can just slap it on top of SLS and you don't have a Block 1 any more.QuoteAlso, where does page 12 say that "you can't do that"? 'Cause the "takeaway" is that there is a "sizeable solution space for a 2 stage lander", that exists within the "SLS Block 1+" capability.6) Block 1+ is not Block 1. Page 12 says that "No Block 1 solutions exist without SLS element to perform LOI". In other words, the lander can't do it, which is what I said.
Quote from: 93143So if you're not allowed to further modify the ICPS to drastically increase its TLI capability, what you need is a manned lunar lander that weighs no more than an Orion and has enough delta-V for LOI, landing, and launch back to HLO. According to page 12, you can't do that...Huh? In my world, the ICPS is designed to support this [Edoit: multi-launch, with LEO assembly] lunar mission when placed on top of the 70ton SLS. If it is currently incapable of doing this, and it can't be changed since it is already designed and built, then clearly, in my world, there is little intention for mission accomplishment. The lunar mission should not be held hostage by the current "model" of ICPS.
Also, where does page 12 say that "you can't do that"? 'Cause the "takeaway" is that there is a "sizeable solution space for a 2 stage lander", that exists within the "SLS Block 1+" capability.
Whatever acronym you want to call the upper stage is fine, but it should not be arbitrarily limited to a stage that cannot do the job.
If the "low nine figures" is "peanuts compared to a real new upper stage", and this is seen as a financial problem preventing the design of a "real", "new" upper stage
then how come a "capable CPS" should only be a "bit more expensive than the ICPS"?
"Of course", in my view only, where there is LEO assembly of that which is needed for TLI and lunar landing.
If you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).
The style of your reply proves our point somewhat: rich on details etc, but not connected with the real world to some degree. But you are correct that the Presidential & NASA Leadership want to do very little.As for adding New Zealand in there, probably for my benefit; N.Z. wont be getting involved in anyone's space program - a population of only 4.5 million with tens of billions in Earthquake damage to fix has other priorities.
Quote from: MATTBLAK on 03/18/2013 05:47 pm<snipped everything>
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Quote from: HappyMartian on 03/19/2013 02:07 pmQuote from: MATTBLAK on 03/18/2013 05:47 pm<snipped everything>Throwing in my 2 cents...You seem to be accusing each other of "being out of touch with reality". And that is exactly what you both are: out of touch with reality. With the current state of affairs on the planet (regardless of them being economic, political or whatever) there will never be an L2 station, let alone a colony on the moon doing ISRU. You two having an argument over them subjects is an utter waste of effort. Not to mention it being a rather effective way to pollute this thread with yet another pointless back-and-forth.
Quote from: 93143 on 03/19/2013 02:30 amIf you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).Of course, I'm not in charge. If I were, I'd lay out a plan along these lines:Launch a 70 ton SLS with capsule, SM and lander to LEO. Launch a second 70 ton SLS with a fully loaded 70 ton EDS to LEO. Dock the two, and send 'em up to the Moon. That's 140 tons in LEO, more than one Saturn V could get to LEO.
"Second stageEngines 1 LE-5BThrust 137 kN (30,798 lbf)Specific impulse 447 secBurn time 534 secondsFuel LOX/LH2"From: H-IIA WikipediaAt: http://en.wikipedia.org/wiki/H-IIAAsk Europe and Japan to build the CPS.Ask Russia, China, and India to work together to build the Lander.Say "Please! And smile politely."See: H-IIA Launch VehicleAt: http://www.jaxa.jp/pr/brochure/pdf/01/rocket01.pdf
Quote from: JohnFornaro on 03/19/2013 01:23 pmQuote from: 93143 on 03/19/2013 02:30 amIf you're limited to Block 1, the only available EDS (a) isn't big enough to send even the remainder of a single full SLS launch to the moon, and (b) doesn't last long enough on orbit to daisy-chain (even if it had AR&D capability, which I'm pretty sure it doesn't).Of course, I'm not in charge. If I were, I'd lay out a plan along these lines:Launch a 70 ton SLS with capsule, SM and lander to LEO. Launch a second 70 ton SLS with a fully loaded 70 ton EDS to LEO. Dock the two, and send 'em up to the Moon. That's 140 tons in LEO, more than one Saturn V could get to LEO.You continue to be focused on the "70 ton[ne]" figure.
Besides the fact that it's at least 20 tonnes short of the thing's true LEO performance, you seem to be advocating building a large EDS without acknowledging that this advances the Block designation.Block 1 with a large EDS is Block 1B.The above is of course just a technicality, but it is relevant to understanding the Moon First presentation. And I recognize that you prefer using notional payload over block designators, but as it happens the Block 1B CPS (unlike the early concepts) can be burned to reach orbit, leading to a higher maximum LEO payload - the Boeing presentation gives 118 tonnes, which is 130 tons...
NASA could certainly do something like what you propose. Just not with Block 1, by definition.
...it's not funny when I say that, let alone the other guy.
The various Block iterations are deliberately confusing the issue. Here's today's example: Block 1+, which covers the timeframe between Block 1 and Block 1A, I suppose.
As updates to Block 1 are still in work, Block 1A will be referred to as Block 1+
I continue to object to their intent to build the 130 ton LV first, before even proposing payloads and missions.
Now the EDS must be called upon to do the circularization burn. To me, this is ridiculous.
It starts sounding like a self fulfilling prophecy, with an absurd outcome: To get three or four astros to ISS in Orion, you need to have a 130 ton SLS, and a partially filled, mostly ballasted EDS.
Quote from: 93NASA could certainly do something like what you propose. Just not with Block 1, by definition.Bingo.By definition. They could, but they don't want to.There is no physical principle which prohibits a comprehensive, multi-decadal lunar, lagrangian, or martian mission profile, using LEO assembly, and multiple launches of Block 1, the 70 ton (or tonne) version of the SLS.