tkdguy Posted January 18, 2009 Report Share Posted January 18, 2009 Given that the atmosphere on Mars is a lot thinner than ours, would airplanes work there? I know small drones would. But is it possible to have a plane that can carry a human being feasible there? Quote Link to comment Share on other sites More sharing options...
McCoy Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? Given that the atmosphere on Mars is a lot thinner than ours' date=' would airplanes work there? I know small drones would. But is it possible to have a plane that can carry a human being feasible there?[/quote'] On the plus side you are dealing with less gravity. On the minus side you're dealing with a lot less air. I'm thinking at least twice the wing area of an earthly plane. Also jets, no prop planes. Quote Link to comment Share on other sites More sharing options...
shadowcat1313 Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? if your technology allows things like contragrav or maglev or repulsor technologies your probably better off with that what about something like ducted fans or Wing In Ground Effect Technologies? that or something akin to a Plasma Turbine[Traveller calls this an Magneto Hydrodynamic Turbine] Quote Link to comment Share on other sites More sharing options...
tkdguy Posted January 18, 2009 Author Report Share Posted January 18, 2009 Re: Martian Airplanes? I was thinking of a hard science, near future setting. So no contragravity. I doubt maglev technology would be advanced enough to allow flight at this time. But thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
shadowcat1313 Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? nods, although it wont work in a really thin atmosphere, there are examples of early contragrav that use the CG to generate lift and another method to generate thrust, either a set of ducted fans or plasma thrusters for example Andy Keiths Fifth Foreign Legion books being one example, another being Traveller the New Era in general. Quote Link to comment Share on other sites More sharing options...
Sundog Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? I have serious doubts that WIGE would work at all; I don't think you could build up a sufficient pressure wave to be able to surf it. Magnetic lift couldn't work at all - Mars has no magnetic field. I sem to recall a piece on this from Scientific American a while back, about needing roughly three times the wingspread to gain equivalent lift, as though the gravity is about one third of Earth's, the air pressure is even less. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted January 18, 2009 Author Report Share Posted January 18, 2009 Re: Martian Airplanes? What's WIGE? Quote Link to comment Share on other sites More sharing options...
gewing Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? What's WIGE? Wing In Ground Effect very efficient, but... Quote Link to comment Share on other sites More sharing options...
Vulcan Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? I was thinking of a hard science, near future setting. So no contragravity. I doubt maglev technology would be advanced enough to allow flight at this time. But thanks for the suggestions. That and if I recall correctly, Mars doesn't have much of a magnetic field left... Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted January 18, 2009 Report Share Posted January 18, 2009 Re: Martian Airplanes? Well, if you're really interested in this question, I suggest you check out the flight simulator called X-Plane. Unlike other flight simulators, it does NOT use pre-computed performance data for the airplanes; instead, it calculates the airflow and effects in real time based on the shape of the aircraft. This allows it to be a great tool for prototyping aircraft designs, and has been used for this purpose by several real-life firms, including Scaled Composites for testing of their X-Prize winning "Spaceship One". It ALSO means that you can tell the program to use Martian gravity and air density and see what flying on Mars is like. In fact, it COMES with a Mars environment. I can tell you that flying on Mars is . . . interesting, because to get airborne you need VERY high speeds, even with huge wings. Then when you try to maneuver, you discover the OTHER effect of thin atmosphere: your control surfaces don't do much. Quote Link to comment Share on other sites More sharing options...
Vulcan Posted January 19, 2009 Report Share Posted January 19, 2009 Re: Martian Airplanes? Would choppers work on mars? Granted they would take huge rotors, but that might solve the maneuverability problem... Quote Link to comment Share on other sites More sharing options...
tkdguy Posted January 19, 2009 Author Report Share Posted January 19, 2009 Re: Martian Airplanes? I hadn't considered choppers. Maybe they'll work. I'll look for that X-plane program. Thanks again for all the help. Quote Link to comment Share on other sites More sharing options...
Basil Posted January 19, 2009 Report Share Posted January 19, 2009 Re: Martian Airplanes? The atmospheric pressure at the surface of Mars varies significantly, but can be approximated as .01 that of Earth. The surface gravity is about 0.38 that of Earth. If the area of wing needed is inversely proportional to the atmospheric pressure and directly proportional to the gravity, you would need a wing 38 times as large on Mars as on Earth, to lift the same mass of engine, cabin, controls, etc. (note, MASS, not weight). Such a wing is, itself, of significant mass, so that starting from a given terrestrial configuration, you not only need a larger wing, you now need to lift that more massive wing, which makes the wing even bigger, which is yet more mass to lift, needing a bigger wing, which means.... Thus, the design starts "chasing its own tail." I don't know if one can eventually "catch up," or if it simply isn't possible. I'd bet it can't be done. Mind you, putting wings for control on, essentially, a rocket, might very well be workable. Quote Link to comment Share on other sites More sharing options...
Sundog Posted January 19, 2009 Report Share Posted January 19, 2009 Re: Martian Airplanes? I know that most of the designs NASA has looked at have incorporated or been primarily LTA models. What makes them viable is the high percentage of Carbon Dioxide in Mars' atmosphere - it's a quite heavy gas, so you get more lift to offset the low pressure. Quote Link to comment Share on other sites More sharing options...
Captain Obvious Posted January 19, 2009 Report Share Posted January 19, 2009 Re: Martian Airplanes? I'm not sure how much lifting power you'd be able to get from a gasbag in such a thin atmosphere. At any rate, air travel is certainly not going to be easy on Mars. The best thing to do is work on getting a reliable road system built as early as possible. Quote Link to comment Share on other sites More sharing options...
Lawnmower Boy Posted January 19, 2009 Report Share Posted January 19, 2009 Re: Martian Airplanes? At any rate' date=' air travel is certainly not going to be easy on Mars. The best thing to do is work on getting a reliable road system built as early as possible.[/quote'] But canals would work so much better! Quote Link to comment Share on other sites More sharing options...
Cancer Posted January 21, 2009 Report Share Posted January 21, 2009 Re: Martian Airplanes? For real: Proposed Mars airplane mission I seem to remember hearing about a Mars airplane concept while in grad school, which means early to mid 1980s. For a science recon aircraft, you would never land the vehicle. You have as much velocity as you can handle (or more) on your initial descent for free. Of course, the large wingspan needed would need a clever stowage and deployment mechanism on that descent, or you'll tear the aircraft apart on initial insertion. I think if you did land you'd have to do so in a rocket-assisted VTOL fashion; you certainly can't count on anything like a runway. The low martian gravity does mean the atmospheric pressure drops off slower with altitude there than it does on Earth, so that you can fly at higher altitudes if you want. If you can get a good glide ratio, you can get quite a long distance. Helicopters have large power requirements and very severe full-time active control requirements which seems like bad things in a remote vehicle. I don't know enough about autogyros and the like to comment about them. Reducing wing area is attractive (large light wings are more vulnerable to damage) but the power requirements may be prohibitive. A challenge for any long-term aircraft is the seasonal global dust storms that Mars has. Quote Link to comment Share on other sites More sharing options...
gewing Posted January 21, 2009 Report Share Posted January 21, 2009 Re: Martian Airplanes? For real: Proposed Mars airplane mission I seem to remember hearing about a Mars airplane concept while in grad school, which means early to mid 1980s. For a science recon aircraft, you would never land the vehicle. You have as much velocity as you can handle (or more) on your initial descent for free. Of course, the large wingspan needed would need a clever stowage and deployment mechanism on that descent, or you'll tear the aircraft apart on initial insertion. I think if you did land you'd have to do so in a rocket-assisted VTOL fashion; you certainly can't count on anything like a runway. The low martian gravity does mean the atmospheric pressure drops off slower with altitude there than it does on Earth, so that you can fly at higher altitudes if you want. If you can get a good glide ratio, you can get quite a long distance. Helicopters have large power requirements and very severe full-time active control requirements which seems like bad things in a remote vehicle. I don't know enough about autogyros and the like to comment about them. Reducing wing area is attractive (large light wings are more vulnerable to damage) but the power requirements may be prohibitive. A challenge for any long-term aircraft is the seasonal global dust storms that Mars has. I saw something in a "Colby" book when I was a kid, where they demonstrated inflatable flight surfaces using a gas generator to fill them. THere was some discussion of using them to counter damage and get planes home... I think they would be more practical for primary lift surfaces, where bulk and mass when stowed are critical. Quote Link to comment Share on other sites More sharing options...
The Weapon Posted January 21, 2009 Report Share Posted January 21, 2009 Re: Martian Airplanes? Given that the atmosphere on Mars is a lot thinner than ours' date=' would airplanes work there? I know small drones would. But is it possible to have a plane that can carry a human being feasible there?[/quote'] Sure they work, you just might have to go faster before takeoff, which is easier because there's less air resistance. Atmosphere on Earth averages 101.325 kPa, on Mars it's 0.6 kPa. "Mars's mean surface pressure equals the pressure found 35 km above the Earth's surface." (all this from wikipedia.org). Since planes can fly at 35 km above earth they can fly on Mars. You just need big engines and to go real fast. Quote Link to comment Share on other sites More sharing options...
Vulcan Posted January 22, 2009 Report Share Posted January 22, 2009 Re: Martian Airplanes? Sure they work, you just might have to go faster before takeoff, which is easier because there's less air resistance. Atmosphere on Earth averages 101.325 kPa, on Mars it's 0.6 kPa. "Mars's mean surface pressure equals the pressure found 35 km above the Earth's surface." (all this from wikipedia.org). Since planes can fly at 35 km above earth they can fly on Mars. You just need big engines and to go real fast. A very few planes can fly that high (35000 meters roughly equals 95,000 feet, right?). SR-71, F-15 (maybe), XB-70 (when it was operational), X-15... That's about all I can think of offhand. Certainly not airliners, or even most military aircraft. I think that even exceeds the capabilities of the U-2 (though not by much). Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted January 22, 2009 Report Share Posted January 22, 2009 Re: Martian Airplanes? You also have to deal with the fact that moving enough of the thin air to generate thrust is difficult. It's actually HARDER to get up to flight speed because of that. Then you have to deal with your huge ground speed, and the fact that you're moving at very high speeds through air that doesn't offer good "traction" for maneuvering. Quote Link to comment Share on other sites More sharing options...
gewing Posted January 22, 2009 Report Share Posted January 22, 2009 Re: Martian Airplanes? I have my doubts about lighter than air craft also. I suppose they could work, but doesn't mars have winds of several hundred kph? Imagine a blimp hitting Olympus Mons at that speed:idjit: Quote Link to comment Share on other sites More sharing options...
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