simonbp - 23/2/2007 6:48 AMSomething like it could be the Mars lander in the ESA's baseline Mars mission: ftp://ftp.estec.esa.nl/pub/aurora/Human_Missions_to_Mars/HMM_Executive_Summary_Final_Version.pdf
JonSBerndt - 24/2/2007 4:28 PMThe charts from John Connolly's lecture earlier this week are up on our AIAA Houston web site:http://www.aiaa-houston.org/cy0607/event-22feb07/Connolly_AIAA_2-20-07.pdfThe main site is www.aiaa-houston.org.
Marsman - 24/2/2007 5:49 PMI'm not too keen on the wet workshop idea, it might be to much work for little benefit. I really liked the MSFC lander, with the hab in the middle of the propellant tanks. The ATHLETE system looked great, but how does it work?
JonSBerndt - 23/2/2007 12:26 PMOne concept goal seen in several illustrations is a minimalized ascent stage crew cabin, with additional habitable volume in an adjacent position. So, instead of discarding the entire habitable volume after ascent from the moon, some of it remains on the lander, in order to begin building up a base.
GSFC-JSC-GRC Lunar Lander ConceptVertical configuration with airlock re-used as ascent crew cabin. ...Focus• Airlock-based ascent stage more fully
GraphGuy - 2/3/2007 3:30 PM Would you rather spend 6 months inside various tin cans or inside a big dome?
Also why land with one engine and take off with another?
GraphGuy - 2/3/2007 3:30 PMI think that if you could land a dedicated tractor that it would be superior to walking over every hab module with ATHELETE. Why waste ATHELETE's weight on every landing, why not just land one tractor/crane and reuse it every mission? Food for thought.
GraphGuy - 2/3/2007 3:30 PMI'm no rocket scientist, but when you can bury yourself in regolith, inflatable > hardshell. Inflatable gives more space to do more things and you can always attach dedicated hard modules (e.g. airlock). Regolith means there is next to no micrometeorite danger and that you aren't directly exposed to the sun. Would you rather spend 6 months inside various tin cans or inside a big dome?
GraphGuy - 2/3/2007 3:30 PMAlso why land with one engine and take off with another? Why not share a common engine for descent and ascent and have it use common propellants? Reliability issues? Poor performance compared to LH2/LOX? Carrying larger tanks up on ascent?
nacnud - 2/3/2007 9:50 PMQuoteAlso why land with one engine and take off with another?Safety and mass minimisation. The decent engine might kick up dust and rocks which could damage it or the decent stage. The ascent engine has to work or it's LOC. Also you want to minimise the mass of a ascent stage, separating the ascent and descent stages in one way to do this.
CFE - 15/3/2007 5:20 AMIn looking at the recurring theme of "minimal ascent cabins," an obvious question comes to mind. Why not come up with a minimalist lander that would touch down next door to a larger habitat module for the astronauts to live in?
Jim - 15/3/2007 8:54 AMIt doesn't make sense for the first phase of lunar mission, i.e. the sorties. One lander is needed that supports 4 crew for x days. The first phase will have landers going to different places to find a spot for the first base
copernicus - 30/3/2007 9:54 AMI still find Lockheed-Martin's proposed Lunar Lander (LASM) to be the most realistic and flexible.
Norm Hartnett - 2/4/2007 9:23 PMThe above combined with this articlehttp://www.nasaspaceflight.com/content/?cid=5063What I find most interesting about this is that it is not dependant on the Ares/Constellation LVs. Using the Atlas V Heavy means that an alternative to the NASA ESAS exists and that some form of lunar operations may be viable using existing LVs if the CEV can be launched on some other LV besides the stick.With robotic precursors delivering both payload and multiple power generation capabilities as well as a backup ascent module the initial base would be ready for assembly prior to the first manned mission. This is a well thought out program and I would love to see what the cost figures would be.
Jim - 15/3/2007 8:54 AMQuoteCFE - 15/3/2007 5:20 AMIn looking at the recurring theme of "minimal ascent cabins," an obvious question comes to mind. Why not come up with a minimalist lander that would touch down next door to a larger habitat module for the astronauts to live in?It doesn't make sense for the first phase of lunar mission, i.e. the sorties. One lander is needed that supports 4 crew for x days. The first phase will have landers going to different places to find a spot for the first base
simonbp - 15/3/2007 5:02 PMQuoteJim - 15/3/2007 8:54 AMIt doesn't make sense for the first phase of lunar mission, i.e. the sorties. One lander is needed that supports 4 crew for x days. The first phase will have landers going to different places to find a spot for the first base... And Griffin's recent comments suggest that after 2021 there will be 1 sortie (not lunar base) mission each year, in addition to 2 base crew rotations and 1 base cargo. So, to keep from having to support two different landers, you want as much commonality as possible between the sortie and base landers...Simon
vanilla - 24/2/2007 12:18 PMIf they want to move towards a sustainable, reusable architecture someday with ISRU (which I have to assume is the reason for the South Pole landing site) then they need to moving away from staging, not towards it. Otherwise, they will be looking at a total lander redesign when they want to get to a better architecture.
alexterrell - 9/4/2007 3:46 PMDidn't see this comment, but in principle, wouldn't it be more efficient to scrap the sorties, and instead land a really capable Rover able to cover several thousand kilometres?Has this trade-off been done?
simonbp - 10/4/2007 2:14 PMQuotealexterrell - 9/4/2007 3:46 PMDidn't see this comment, but in principle, wouldn't it be more efficient to scrap the sorties, and instead land a really capable Rover able to cover several thousand kilometres?Has this trade-off been done?See the JPL design in the above document; basically it's a lunar base on wheels that travels from nearside equatorial down to the south pole, accumulating modules along the way...Simon
Ankle-bone12 - 19/4/2007 6:43 PManybody see the new "returning to the moon" trailer on the nasa web sight?heres the URLhttp://www.nasa.gov/mission_pages/constellation/main/index.html
copernicus - 25/5/2007 4:04 PM What are the prospects for launching this with the Ares-1 or the Atlas-5 or the Delta-4, perhaps with a partial propellant load on the Lunar Lander? I think that we need to start bending metal on the Lunar Lander soon.
Norm Hartnett - 2/4/2007 8:23 PMThe above combined with this articlehttp://www.nasaspaceflight.com/content/?cid=5063What I find most interesting about this is that it is not dependant on the Ares/Constellation LVs. Using the Atlas V Heavy means that an alternative to the NASA ESAS exists and that some form of lunar operations may be viable using existing LVs if the CEV can be launched on some other LV besides the stick.-----"Now is the time to question our operating assumptions and technical dogmas." Mike Griffin
CuddlyRocket - 27/2/2007 2:33 AMQuoteJonSBerndt - 23/2/2007 12:26 PMOne concept goal seen in several illustrations is a minimalized ascent stage crew cabin, with additional habitable volume in an adjacent position. So, instead of discarding the entire habitable volume after ascent from the moon, some of it remains on the lander, in order to begin building up a base.Yes, that does seem a good idea that would seem to have a high probability of being in the final design. Not only for the reason you give, but also because such an ascent module would require a smaller ascent engine and therefore smaller fuel tanks, freeing mass for even more usable payload.
alexterrell - 29/5/2007 3:27 AM1. Design a very light weight lunar ascent module to go from Lunar Surface to an orbiting CEV with 4 astronauts. Dig out the old Langley-Light studies. Journey time will be no more than a few hours, so the module can be unpressurized. Total ascent stage mass could be of the order of 3 tons. (Compared to the ESAS baseline, that would allow an extra 7 tons to remain on the surface.)
MKremer - 29/5/2007 4:18 AMQuotealexterrell - 29/5/2007 3:27 AM1. Design a very light weight lunar ascent module to go from Lunar Surface to an orbiting CEV with 4 astronauts. Dig out the old Langley-Light studies. Journey time will be no more than a few hours, so the module can be unpressurized. Total ascent stage mass could be of the order of 3 tons. (Compared to the ESAS baseline, that would allow an extra 7 tons to remain on the surface.)Umm, but then that requires eithera) the CEV to depressurize to allow entry from vacuum which also requires an extra CEV O2 press load mass over contingency requirements, orb) a docking airlock adapter with its own O2 supply either as part of the lunar ascent module, or attached to the LSAM at launch and then left docked to the CEV until the ascent module returns... and there goes quite a bit of your extra mass 'savings'(of course the CEV, at least as it stands now, will not have any type of airlock; at least not without wholesale redesigns of both CEV/SM, and lots more money to do it)
alexterrell - 29/5/2007 6:26 PMGood point - I thought CEV would have an airlock, but it appears not. This will limit its flexibility in the future.
Justin Wheat - 29/5/2007 11:07 PMThe cev will only provide the seating and controls for the ride into space. The lunar lander will be what the crew goes into to get out the door.
clongton - 30/5/2007 7:44 AMWhat you're saying (admitting) is that the CEV is useless unless it docks to something (ISS/LSAM/etc)
simonbp - 30/5/2007 10:29 AMQuoteclongton - 30/5/2007 7:44 AMWhat you're saying (admitting) is that the CEV is useless unless it docks to something (ISS/LSAM/etc)Well Duh! As Jim said, Orion is a crew taxi, a passenger means of transportation. Generally, means transportation are useless unless they go somewhere. Likewise, the Lunar Lander is useless unless it lands on the Moon!Simon
02hurnella - 30/5/2007 4:04 PMSo what will any heavy cargo lander be like? >How will the resupply landers be different? (not equipped with return stages? Or will they be, as a fail-safe)
simonbp - 31/5/2007 2:40 AMQuote02hurnella - 30/5/2007 4:04 PMSo what will any heavy cargo lander be like? >How will the resupply landers be different? (not equipped with return stages? Or will they be, as a fail-safe)That (like pretty much else about the lander) is yet to be determined, but since it is being directly injected to the moon, without any Orion to lug around, the cargo lander will probably just be a standard descent stage with more stuff on top. Some of the lander designs in the presentation (at the start of this thread) have a combined airlock/ascent stage, so if such a design is sent, they'd have to bring the ascent stage (to get into the pressurized hab). On the other hand, if the "cargo" is unpressurized, like, say, a lunar bulldozer, then they probably wouldn't carry an ascent stage.For an idea what I mean, look at the post-Apollo plans:AES: http://www.astronautix.com/craft/aesrbase.htmALSS: http://www.astronautix.com/craft/alsrbase.htmLESA: http://www.astronautix.com/craft/lesrbase.htmSimon
For LESA a "clean sheet of paper" direct lunar lander, the Lunar Landing Vehicle (LLV) was conceived, which would take full advantage of the Saturn V trans-lunar payload capability. The LLV would have a payload of 12,700 kg, which would include life support systems and consumables, a shelter, and a Lunar Roving Vehicle. The shelter was designed for six crew, but only three would use it in the early missions. It consisted of an airlock, a cylindrical domed center structure, and an outer toroid work area. Adequate space existed in the toroid for suited astronauts to function and operate the controls in case of an emergency depressurization. Net LLV translunar injection mass was 41,000 kg (equivalent to a 43,000 kg mass payload for the Saturn V, including fairings). Landed mass was 18,000 kg, including 11,5000 to 13,500 kg payload (depending on whether a one or two stage LLV was developed), 900 to 1,000 cu m of living area, and access platforms 1.6 to 3.0 m above the surface, depending on the staging concept. Engines for the LLV would be modifications of the RL10-A3 Lox/LH2 engine.
Marsman - 29/5/2007 11:39 PMThe descent module is not reused and can be designed so that any equipment needed for future missions is protected.
A_M_Swallow - 20/7/2007 3:48 PMQuoteMarsman - 29/5/2007 11:39 PMThe descent module is not reused and can be designed so that any equipment needed for future missions is protected.If the Centenary competition entry is any guide the ascension motor will be sufficiently hot that it can melt concrete, how much mass will the protection add?After 3 landings would it be easier to create a special launch pad?Possibly using a mining rover to carry the ascension stage to the launch pad.
Jim - 21/7/2007 6:27 AMThere first will be sortie missions, 2 per year for awhile, then the lunar base, which will take a good number of flights over a few years. Mining is not part of the plan and it won't be done by NASA. It won't start for 10 or more years after the first landingLanding is different that liftoff, the descent stage will be exposed to the ascent engine for a momentPS. It is ascent engine or stage, not ascension