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Lunar Lander in a 5.2m faring?
Quite a few people have criticized the NASA architecture for developing
new launch vehicles whilst lower cost alternatives exist, or will exist. Suppose in 2011, - SpaceX has flown Falcon 9 succesfully, including its 25 ton version. - The President says "Constellation is a good idea, but needs to be done cheaper, so scrap the SDHLV and save $10 billion". A descent moon mission could be flown with three Falcon 9 launched Earth Departure Stages, with no orbital propellant transfer, and "assembley" consisting of joining up units. (Already planned). The CEV could be launched on the Stick (only a NASA vehicle being good enough for its Astronauts). The Earth Departure Stages would be cheap, and assembled in volume, and launched well before the other flights. But how can you get a descent lunar lander, capable of landing ~10 tons on the lunar surface, into the 5.2m dimater faring offered by SpaceX (or Boeing, LM, or the Stick)? Can this be done without orbital assembley? One idea I had would be a lander that consists of two propulsion units that would fit either side of the payload, and would be joined across the top by a "bridge". The payload would fit in the middle, suspended from the joining bridge. This bridge would be telescopic, enabling the two propulsion units to be launched together inside a single faring. This has the advantage that no crane or ramp is needed to lower the payload to the lunar surface, and payload can be of almost any shape and size. However, it needs two propulsion units, and both must work, doubling failure probability. and engine out would lead to certain mission destruction. |
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Lunar Lander in a 5.2m faring?
On 23 Oct 2005 03:56:21 -0700, "Alex Terrell"
wrote: But how can you get a descent lunar lander, capable of landing ~10 tons on the lunar surface, into the 5.2m dimater faring offered by SpaceX (or Boeing, LM, or the Stick)? Can this be done without orbital assembley? Maybe, but the simplest solution would be to launch the lander without any fuel tanks first, and then attach fuel tanks (launched seperately or uninstalled on the same launcher.) in orbit. That would take some ISS-like assembly, though. Brian |
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Lunar Lander in a 5.2m faring?
Brian Thorn wrote:
:On 23 Oct 2005 03:56:21 -0700, "Alex Terrell" :wrote: : :But how can you get a descent lunar lander, capable of landing ~10 tons :on the lunar surface, into the 5.2m dimater faring offered by SpaceX :(or Boeing, LM, or the Stick)? : :Can this be done without orbital assembley? : :Maybe, but the simplest solution would be to launch the lander without :any fuel tanks first, and then attach fuel tanks (launched seperately r uninstalled on the same launcher.) in orbit. That would take some :ISS-like assembly, though. And you're back to talking about assembly of pressure fittings in space. This is almost always a bad idea, particularly for relatively high pressure fittings like fuel feed lines. Space assembly is HARD, people. It's difficult and clumsy work. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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Lunar Lander in a 5.2m faring?
Fred J. McCall wrote: Brian Thorn wrote: :On 23 Oct 2005 03:56:21 -0700, "Alex Terrell" :wrote: : :But how can you get a descent lunar lander, capable of landing ~10 tons :on the lunar surface, into the 5.2m dimater faring offered by SpaceX :(or Boeing, LM, or the Stick)? : :Can this be done without orbital assembley? : :Maybe, but the simplest solution would be to launch the lander without :any fuel tanks first, and then attach fuel tanks (launched seperately r uninstalled on the same launcher.) in orbit. That would take some :ISS-like assembly, though. And you're back to talking about assembly of pressure fittings in space. This is almost always a bad idea, particularly for relatively high pressure fittings like fuel feed lines. Space assembly is HARD, people. It's difficult and clumsy work. There's assembley and there's assembley. I was hoping to keep itdown to rendez-vous and attachment, as proposed by NASA. However, for this at least one of the modules needs thrust. As for high pressure feedlines, I assume they're only high pressure when the valve is turned on. And even if their valveless, joiming high pressure feed lines in space should be relatviely straight forward, as long as they align correctly. |
#5
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Lunar Lander in a 5.2m faring?
"Alex Terrell" wrote in message oups.com... As for high pressure feedlines, I assume they're only high pressure when the valve is turned on. And even if their valveless, joiming high pressure feed lines in space should be relatviely straight forward, as long as they align correctly. And if they don't align correctly, a billion plus dollar mission has just been wasted. |
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Lunar Lander in a 5.2m faring?
"Alex Terrell" wrote:
: :Fred J. McCall wrote: : Brian Thorn wrote: : : :On 23 Oct 2005 03:56:21 -0700, "Alex Terrell" : :wrote: : : : :But how can you get a descent lunar lander, capable of landing ~10 tons : :on the lunar surface, into the 5.2m dimater faring offered by SpaceX : :(or Boeing, LM, or the Stick)? : : : :Can this be done without orbital assembley? : : : :Maybe, but the simplest solution would be to launch the lander without : :any fuel tanks first, and then attach fuel tanks (launched seperately : r uninstalled on the same launcher.) in orbit. That would take some : :ISS-like assembly, though. : : And you're back to talking about assembly of pressure fittings in : space. This is almost always a bad idea, particularly for relatively : high pressure fittings like fuel feed lines. : : Space assembly is HARD, people. It's difficult and clumsy work. : :There's assembley and there's assembley. I was hoping to keep itdown to :rendez-vous and attachment, as proposed by NASA. However, for this at :least one of the modules needs thrust. Yep. And it's not the 'attach fuel tanks in orbit' model anymore. :As for high pressure feedlines, I assume they're only high pressure :when the valve is turned on. Correct, but is there a point there? You still have to get the joined in such a way as to stand up to operating pressure. :And even if their valveless, joiming high ressure feed lines in space should be relatviely straight forward, as :long as they align correctly. Just a wave of the Technology Fairy's wand away.... -- "We come into the world and take our chances. Fate is just the weight of circumstances. That's the way that Lady Luck dances. Roll the bones...." -- "Roll The Bones", Rush |
#7
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Lunar Lander in a 5.2m faring?
"Fred J. McCall" wrote in message ... Brian Thorn wrote: :On 23 Oct 2005 03:56:21 -0700, "Alex Terrell" :wrote: : :But how can you get a descent lunar lander, capable of landing ~10 tons :on the lunar surface, into the 5.2m dimater faring offered by SpaceX :(or Boeing, LM, or the Stick)? : :Can this be done without orbital assembley? : :Maybe, but the simplest solution would be to launch the lander without :any fuel tanks first, and then attach fuel tanks (launched seperately r uninstalled on the same launcher.) in orbit. That would take some :ISS-like assembly, though. And you're back to talking about assembly of pressure fittings in space. This is almost always a bad idea, particularly for relatively high pressure fittings like fuel feed lines. Space assembly is HARD, people. It's difficult and clumsy work. Why do the feed lines have to be high pressure? Why not have a single set of high pressure tanks on the "core" of your stage, and attach lower pressure fuel and oxidizer tanks to that? This means you'd have to do a series of burns to get where you're trying to go, but it might make the task easier by eliminating those high pressure connections. The Russians have been transferring storable hypergolic fuel and oxidizer from Progress tankers to their stations (including ISS) for years. No EVA or clumsy pressure fittings seem to be required for this to work. Jeff -- Remove icky phrase from email address to get a valid address. |
#8
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Lunar Lander in a 5.2m faring?
"Jeff Findley" wrote:
: :"Fred J. McCall" wrote in message .. . : Brian Thorn wrote: : : :On 23 Oct 2005 03:56:21 -0700, "Alex Terrell" : :wrote: : : : :But how can you get a descent lunar lander, capable of landing ~10 tons : :on the lunar surface, into the 5.2m dimater faring offered by SpaceX : :(or Boeing, LM, or the Stick)? : : : :Can this be done without orbital assembley? : : : :Maybe, but the simplest solution would be to launch the lander without : :any fuel tanks first, and then attach fuel tanks (launched seperately : r uninstalled on the same launcher.) in orbit. That would take some : :ISS-like assembly, though. : : And you're back to talking about assembly of pressure fittings in : space. This is almost always a bad idea, particularly for relatively : high pressure fittings like fuel feed lines. : : Space assembly is HARD, people. It's difficult and clumsy work. : :Why do the feed lines have to be high pressure? How does the fuel get into the engine? Little tiny men with buckets? :Why not have a single set f high pressure tanks on the "core" of your stage, and attach lower ressure fuel and oxidizer tanks to that? This means you'd have to do a :series of burns to get where you're trying to go, but it might make the task :easier by eliminating those high pressure connections. Any task that reduces vehicle capability (as your suggestion above does) no doubt makes things easier. :The Russians have been transferring storable hypergolic fuel and oxidizer :from Progress tankers to their stations (including ISS) for years. No EVA r clumsy pressure fittings seem to be required for this to work. Now you might want to look at the thrust developed and burn durations. I don't see any of those vehicles going to the Moon, landing, and then taking back off. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#9
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Lunar Lander in a 5.2m faring?
In article ,
Fred J. McCall wrote: :Maybe, but the simplest solution would be to launch the lander without :any fuel tanks first, and then attach fuel tanks... And you're back to talking about assembly of pressure fittings in space. This is almost always a bad idea, particularly for relatively high pressure fittings like fuel feed lines. The Russians made it work quite routinely -- untouched by human hands -- for refueling Mir (and, I believe, ISS) from Progress tankers. There's nothing that hard about it. -- spsystems.net is temporarily off the air; | Henry Spencer mail to henry at zoo.utoronto.ca instead. | |
#10
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Lunar Lander in a 5.2m faring?
"Fred J. McCall" wrote in message ... "Jeff Findley" wrote: :The Russians have been transferring storable hypergolic fuel and oxidizer :from Progress tankers to their stations (including ISS) for years. No EVA r clumsy pressure fittings seem to be required for this to work. Now you might want to look at the thrust developed and burn durations. I don't see any of those vehicles going to the Moon, landing, and then taking back off. Which is why I've said before that I think in orbit transfer of LOX and other mild cryogens (like methane) ought to be a technology that NASA should be researching now. After all, once we set our sights on Mars, even the SDHLV is going to be too small to launch a fully fueled Mars transfer stage. Why not start working on the technology needed now? Jeff -- Remove icky phrase from email address to get a valid address. |
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