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Is it feasible to land on Mars and come back?
Bar the development of some revolutionary technology, is it realistic to
think that we can land on Mars and come back? Say we want to bring a piece of Martian rock back to Earth. A lander carrying a rover and an ascent module would land on the planet. The rover would move about, pick up a rock, and bring it back to the ascent module. The module is then launched back into space to rendezvous with a return vehicle. It seems to me that the size of lander would be prohibitively large, as the ascent module would need to carry enough fuel to enter into Martian orbit. Compared to the Moon's, Mars' gravity is much stronger. Mars also has an atmosphere, which means thermo-shieldings on both the lander and the ascent module. The return vehicle would be fairly large too, as it needs to carry fuel for returning to Earth. In addition, it would carry the reentry module and equipment for monitoring the Martian atmosphere. Even if we use two launches, the rockets used to carry them into space would be gargantuan. Perhaps our current approach to Mars exploration is the only way for the foreseeable future? |
#2
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Is it feasible to land on Mars and come back?
Chung Leong wrote:
It seems to me that the size of lander would be prohibitively large, as the ascent module would need to carry enough fuel to enter into Martian orbit. Compared to the Moon's, Mars' gravity is much stronger. Mars also has an atmosphere, which means thermo-shieldings on both the lander and the ascent module. The return vehicle would be fairly large too, as it needs to carry fuel for returning to Earth. In addition, it would carry the reentry module and equipment for monitoring the Martian atmosphere. Even if we use two launches, the rockets used to carry them into space would be gargantuan. Unless you utilize In-Situ Propellant Production. That's one of the main points in Robert Zubrin's "Mars Direct"-plan. Bring along some Hydrogen, which weighs next to nothing. Make it react with Mars' CO2-atmosphere, creating Methane and water (the Sabatier-reaction). Electrolyze the water into Hydrogen, which is cycled back into the reaction, and Oxygen, which makes a great rocket fuel together with Methane. -- Steen Eiler Jørgensen "Time has resumed its shape. All is as it was before. Many such journeys are possible. Let me be your gateway." |
#3
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Is it feasible to land on Mars and come back?
"Chung Leong"
Bar the development of some revolutionary technology, is it realistic to think that we can land on Mars and come back? It seems to me that the size of lander would be prohibitively large, as the ascent module would need to carry enough fuel to enter into Martian orbit. Compared to the Moon's, Mars' gravity is much stronger. Mars also has an atmosphere, which means thermo-shieldings on both the lander and the ascent module. See this: http://techreports.larc.nasa.gov/ltr...aa-98-2850.pdf Jon |
#4
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Is it feasible to land on Mars and come back?
"Chung Leong" ,
In a message on Sat, 10 Jan 2004 13:54:26 -0500, wrote : "L Bar the development of some revolutionary technology, is it realistic to "L think that we can land on Mars and come back? "L "L Say we want to bring a piece of Martian rock back to Earth. A lander "L carrying a rover and an ascent module would land on the planet. The rover "L would move about, pick up a rock, and bring it back to the ascent module. "L The module is then launched back into space to rendezvous with a return "L vehicle. "L "L It seems to me that the size of lander would be prohibitively large, as the "L ascent module would need to carry enough fuel to enter into Martian orbit. "L Compared to the Moon's, Mars' gravity is much stronger. Mars also has an "L atmosphere, which means thermo-shieldings on both the lander and the ascent "L module. "L "L The return vehicle would be fairly large too, as it needs to carry fuel for "L returning to Earth. In addition, it would carry the reentry module and "L equipment for monitoring the Martian atmosphere. Even if we use two "L launches, the rockets used to carry them into space would be gargantuan. This would depend on how how high an orbit the assent module would need to achieve -- assent module itself could also be abandoned, once the crew and samples transfer to the return vehicle. One possibility would be a several vehicle approach -- sending the return vehicle and/or its fuel separately from the landing vehicle. We have proven the ability to get unmanned stuff to Mars and then spot it with a reasonable degree of accuracy. Note: if the Mars transit vehicles were assembled and launched from Earth orbit (or from a Lunar orbit) there would be various economies realized, since the ships going to/from Mars would not have to contend with Earth gravity well or Earth's atmosphere. "L "L Perhaps our current approach to Mars exploration is the only way for the "L foreseeable future? "L "L "L \/ Robert Heller ||InterNet: http://vis-www.cs.umass.edu/~heller || http://www.deepsoft.com /\FidoNet: 1:321/153 |
#5
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Is it feasible to land on Mars and come back?
In article ,
Chung Leong wrote: Bar the development of some revolutionary technology, is it realistic to think that we can land on Mars and come back? It's certainly feasible, just relatively costly. It seems to me that the size of lander would be prohibitively large, as the ascent module would need to carry enough fuel to enter into Martian orbit. Compared to the Moon's, Mars' gravity is much stronger. Mars also has an atmosphere, which means thermo-shieldings on both the lander and the ascent module. This has been studied at some length. It's a manageable problem, although a painful one. Remember that the ascent module doesn't need to carry a terribly *large* payload into Martian orbit; that helps. Another approach that helps considerably is fueling the ascent module from fuel manufactured on Mars, rather than having to lug the fuel all the way. The return vehicle would be fairly large too, as it needs to carry fuel for returning to Earth. In addition, it would carry the reentry module and equipment for monitoring the Martian atmosphere. The reentry module is quite small, and there is no atmosphere monitoring on the sample return mission -- the return vehicle's job is sample return, not orbital science. Even if we use two launches, the rockets used to carry them into space would be gargantuan. Not really. It's almost certainly feasible with a pair of Titan-class launches; they're just expensive. Doing it with a pair of Deltas is a rather marginal project, which is one reason why it hasn't happened. -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
#6
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Is it feasible to land on Mars and come back?
Chung Leong wrote:
Bar the development of some revolutionary technology, is it realistic to think that we can land on Mars and come back? Yes. All you really need is the willingness to spend a lot of money on launching fuel tanks to LEO. strictly speaking, could have done decades ago. Just nobody has been willing to cough up the money so far, either for a brute force mission or otherwise. Say we want to bring a piece of Martian rock back to Earth. A lander carrying a rover and an ascent module would land on the planet. The rover would move about, pick up a rock, and bring it back to the ascent module. The module is then launched back into space to rendezvous with a return vehicle. provided you want a separate return vehicle and the rendezvous. You may very well not want that. -- Sander +++ Out of cheese error +++ |
#7
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Is it feasible to land on Mars and come back?
"Chung Leong" wrote:
The return vehicle would be fairly large too, as it needs to carry fuel for returning to Earth. In addition, it would carry the reentry module I assume by "reentry module", you mean, "reentry to Earth's atmosphere"? If so, it's not really needed. The return vehicle could park itself in Earth orbit and a shuttle (or other vehicle) could rendezvous with it to get the cargo. |
#8
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Is it feasible to land on Mars and come back?
In article ,
Roy Smith wrote: I assume by "reentry module", you mean, "reentry to Earth's atmosphere"? If so, it's not really needed. The return vehicle could park itself in Earth orbit and a shuttle (or other vehicle) could rendezvous with it to get the cargo. Unfortunately, decelerating *into* low Earth orbit is extremely expensive in fuel. No, the return vehicle can't just "park itself" in LEO, not if it has any ordinary propulsion system. For at least some sets of assumptions, it's mass-competitive to have a minimal sample capsule (*not* the whole return vehicle) decelerate into a very high Earth orbit, for retrieval by a station-based tug. The trouble is that no suitable high-performance tug currently exists. -- MOST launched 30 June; science observations running | Henry Spencer since Oct; first surprises seen; papers pending. | |
#9
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Is it feasible to land on Mars and come back?
Roy Smith wrote:
"Chung Leong" wrote: The return vehicle would be fairly large too, as it needs to carry fuel for returning to Earth. In addition, it would carry the reentry module I assume by "reentry module", you mean, "reentry to Earth's atmosphere"? If so, it's not really needed. The return vehicle could park itself in Earth orbit and a shuttle (or other vehicle) could rendezvous with it to get the cargo. Which requires carrying fuel for retrobraking into Earth orbit. If you're willing to pay that penalty, then yes. -- You know what to remove, to reply.... |
#10
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Is it feasible to land on Mars and come back?
Henry Spencer wrote:
Unfortunately, decelerating *into* low Earth orbit is extremely expensive in fuel. Unless you bring an aeroshell and use aerobraking. -- Steen Eiler Jørgensen "Time has resumed its shape. All is as it was before. Many such journeys are possible. Let me be your gateway." |
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