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O.K., let's assume you can make and handle LH2/LOX rocket fuel. I wonder what the fuel consumption might be in a rocket-powered airplane like the one you mention.
I keep thinking about the German WWII rocket fighter, the Me 163. The duration of the powered phase of a typical flight was only 8 to 12 minutes; the rest of the flight being a fast glide back down to the ground.
But that was the 1940s of course and we could surely improve on that sort of performance today, I suppose. But could we improve on it enough to make rocket planes viable on Mars?
That was really the main point of my question.
???
Is ANY airplane feasible on Mars? I don't know.
Rocket powered seems the best solution since there is essentially no O2 for combustion and propellers have little atmosphere to bite into.
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The Helios airplane was neat and all, but with its very low thrust on the ground on Mars, I doubt it could do more than taxi under its own power in the Martian air, it needs far less thrust in "cruise" mode. The length of such a required runway, without a destructively powerful assist, would be prohibitive. Said runway would have to be pretty perfect, any Martian airplanes will be quite fragile, and even here on Earth they worry about anything bigger than gravel for the landing gear's sake. Using a helecopter to lift anything of mass is also impossible due to the same thin atmosphere, you would have better luck with a LOX/Methane or LOX/LH2 rocket-hopper.
Rocket power is also not an option, due to simple fuel capacity problems, reguardless of the fuel used. Reaction-mass engines of any type are not practical for long-range air travel. A jet engine on Earth gets its oxygen for free, cutting the fuel mass required to about 20% of what it would be just counting fuel mass when burning CH4, which doesn't take into account the LOX tanks or how much bigger the plane would be to carry it: a reduction in fuel needed yeilds a nonlinear return in saved mass. Liquid hydrogen needs much more oxygen by-mass than Methane per amount of reaction mass too, not to mention the need for bulky insulated tanks for LH, even if it were plentiful on Mars.
Further, no airplane designed for flight on Earth, save perhaps the Helios or some US Military UAVs, are even remotely compatible with a Mars mission even if the wings were radicly alterd and the structure composed of composit materials, especially not the Harrier fighter jet.
I still favor space-based reconisance whenever possible, yes it is harder to make a long-range camera and such, but to not have to mess with sending the mass down to Mars's surface, or building a finicky gossamer airplane, is a small price to pay... Just send more satelites based on spy sat technology, if one won't do, send MORE. They could also be multi-purpose, serving as a rudimentary GPS on Mars (Mars has no magnetic field, no compass!) and communications to pick up signals from low-powerd remote surface equipment.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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What about a MarsHarrier?
Oof, I've been really busy, so I only have time to make this one post today. Bad, bad idea with the Harrier. I don't want to discourage any creative thought or anything, but it simply wouldn't work. For one thing, the plane is way too big, you'd never fit it in a small enough capsule. Secondly, it would spend way too much fuel, 15 minutes of flight at best. Also, the Harrier's stall speed is about 160 mph on Earth, which translates into a 1,600 mph stall speed on Mars, which is about Mach 2.3.
What I intended for use of astronauts would be a plane more resembling a Pilatus Turbo Porter, superficially anyway. It would naturally be electric, with BIG wings, a big engine, and lightweight construction. It would be a two-seater, with room for recon gear, and have a stall speed of around 25 KIAS (Knots Indicated Airspeed). That translates into a stall speed of 260 mph or so on the ground in zero wind conditions. Hmm, this would be an interesting project for Burt Rutan and Scaled Composites.
With favorable winds, a well designed plane could take-off in a reasonable distance. The take-off and landing rolls could also be helped with aircraft carrier style catapults and arrester gear. Perhaps I should try to design a plane in X-Plane to do this, and then show you some screenshots, just for some trivial evidence that it works.
A mind is like a parachute- it works best when open.
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Hi all,
I have modified (yep, once again), my martian methane/O2 propulsed glider.
This time it is like a regular terran glider in the front (with longer wingspan though), another wing at the rear, no vertical surfaces, and to increasea even more the lift in the thin air, a huge, ultra-light semi rigid wing/parachute on top of all that.
I think the former designs didn't provide enough lift.
you can see it at (registration required):
http://www.renderosity.com/viewed.ez?ga … ...New=Yes
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Oh yes, and a solar powerd airplane would have to either fly constantly west faster than Mars rotates, or carry batteries to fly at night. Also remember, that Mars has a much thinner atmosphere per amount of gravity, so I have my doubts if any small airplane can fly effectivly.
Aren't you overlooking the pole-to-pole flightpath? That could be sustained for quite a number of sols by a solar powered electric airplane, suitably designed for Martian atmosphere -based aerodynamics. Ditto, for a hydrogen filled dirigible airship.
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You would have to fly pretty fast I would think to outrun the sunset, and that would preclude being able to loiter over a target of interest.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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At the Mars Society Conference last weekend Dr. Zubrin made a fascinating presentation about a solar powered "CO2 Hopper" for Mars. The model he proposed would be for a Scout misison or a similar early mission to Mars. It would have a total mass of 55 kilograms dry, including a CO2 tank able to hold 30 kilograms of CO2, a beryllium cylinder massing about 15 kg, 10 kg of science payload (cameras, etc.), and wings (which I suppose would be the rest of the 30 kg). The wings would have solar panels able to make about 100 watts of power. The power would be routed to two things: (1) a pump to compress Martian air and fill the tank with liquid CO2 (which is a liquid at Mars ambient temperatures at the pressure of 10 atmospheres), and (2) a heater to heat the cylinder with the beryllium pebblebed. After a month the tank is full with 30 kg of CO2 and the beryllium spheres are blazing hot. CO2 flowing through the pebblebed is heated to the same temperature as the bed and is shot out of nozzles under, in the back, or in the front of the fuselage, allowing the plane to take off and land vertically and accelerate or decellerate. Zubrin gave the following specific impulses: for 500K, 90 seconds; 1000K, 141 seconds; 1500K, 180 seconds; 2000K, 206 seconds; 2500K, 235 seconds. These are theoretical; the achievable specific impulse is about ten percent less. Zubrin assumed that the initial vehicle would operate at 1000K because steel can handle that temperature easily. It would be able to fly 150 kilometers on its 30 kilograms of "propellant." Pretty cool, huh?!
The idea would be to settle down at a spot and take pictures. If a rock 25 meters away looks interesting, jet over to it. If one wants to fly to the top of the Marineris escarpment--or to a ledge half way up--you do so. You could also do low-altitude reconnaisance and photography. This system would knock the socks off the MER rovers. Scaled up enough, one could fly around a pretty good science package. I suppose people could hop around, also, though the long recharge time (30 days) would not work well unless they were landing at a place with a power source.
- RobS
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There was a university with a scout mission that had a plane that inflated and would have the wings set hard due to epoxy that uv cured. But that mission was dropped from those that were still in the running at that time.
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I have become intrigued by the idea of solar-powered airplanes in Mars lately. I've found two designs that give technical details. One, the Helios, flew on Earth for several years and was in turn the latest successor of a series of smaller prototypes. The other is the "Mars Airborne Exploration Vehicle" designed by an engineering class at the University of Oklahoma. Here are some technical specifications from both:
Vehicle Helios MAEV
Total mass 930 kg 80.5 kg
Wing mass 500kg? 28.0kg
Payload Mass 110kg? 8.0 kg
Fuel cell mass 225 kg 6.0 (batteries)
Miscellaneous 30? 2 (avionics)
Motor Mass 70 10 kg
Wing length/width 75.3/3.6 30.5/1.2
Wing area (m2) 186.6m2 36.6 m2
Wing Loading 5 kg/m2 2 kg/m2
Takeoff velocity ? 31.4 m/sec
Max. velocity 75 m/sec 67 m/sec
Power takeoff/max ? 503/1366 watts
Power output 37 kw (Earth) 1.3 kw (Mars)
Solar array area/mass 180m2/? 17.5 m2/26.3 kg
Note: Helios needs 10 kw in normal flight, which it could make on Mars
The Helios is close to the size of a functioning vehicle on Mars for moving people around; its payload is 300 kg without a power storage system and probably half that with such a system (which would be essential for night flight).
Note that each square meter of solar panel on an aircraft wing on Mars can generate about 3 kilowatt-hours per day, assuming 22% efficient panels. Its mass will be about 1.5 kilograms (including the power conversion equipment). Thus solar panels can make 2 kilowatt-hours per kilogram of solar electric system. In contrast, 1 kilogram of methane and oxygen can make 2.7 kilowatt hours, though it is probably about 2 kilowatt-hours as well once the inefficiencies of conversion to electricity are taken into account. Thus solar power holds the advantage on lengthy flights (especially more than 1 sol in length). If solar panels are 30% efficient they are more efficient even for flights of 1 sol or less. Silane engines might be even more efficient, though, since 3/4 of the mass they need is atmospheric carbon dioxide.
The Helios and MAEV fly at pretty good speeds, too; the MAEV can manage 75 meters per second, which is 270 kilometers per hour and 167 miles per hour. A 24-hour flight could cover over 6,000 kilometers, which is 1/4 of the way around Mars (equator to pole, for example).
One problem is the need for runways for takeoffs and landings. This can be resolved if one is willing to reduce payload further and install a small rocket system for vertical takeoffs and landings. The needed delta-v for one vertical takeoff and one vertical landing (assuming the base of operations has a runway, so the vertical landing and takeoff are needed only at the destination) would be about 150 meters per second, so methane and oxygen would need to total about 5% of the aircraft's total mass.
Another problem would be wind. The Helios was a delicate vehicle; it spontaneously fell apart on its last flight. This problem can partly be fixed by using a biplane or even more (triplane, quadriplane) design. Stacking wings on top of each other allows one to tie them together using guywires and produce a stronger wing system than a single, very long wing, would provide. Multiple stacked wings get decreased lift on Earth, but this problem may be less on Mars because of the very thin air (which I think is unable to propagate shock waves such as are produced by exceeding the speed of sound).
I suspect solar-powered aircraft could not fly at all for 1/4 of every Martian year because of the windy, dusty conditions of the dust storm season. But this may be acceptable, considering that such vehicles require no fuel and would be multiply redundant (the Helios had 14 propellers, and thus could continue to fly if several of them malfunctioned). In fact, a multiple-propeller aircraft with a rocket vertical landing system could be quite a safe vehicle, since the rockets could drain the entire supply of methane-oxygen or hydrogen oxygen in an emergency, and that supply would include the fuel that is storing energy for night flight.
-- RobS
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I hope the table comparing the Helios and MAEV is clear enough. Note that the MAEV is only 10% payload by mass, while the Helios achieves more like 12%. This suggests to me that any decent solar powered plane will have a pretty big mass in order to carry, say, 1 tonne of payload (which Zubrin says is the payload of a Twin-Otter, the workhorse of arctic exploration).
-- RobS
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I had remembered some other space planes for mars scout missions from various Universities. One has done the research needed to deploy after re-entry without landing to get ready to fly. It blew an inflatable set of wings up and then cured them in the martian atmosphere by UV.
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Fascinating link. The aircraft I'm talking about would be assembled by astronauts on the Martian surface. They'd come in pieces many of which might be inflatable, though possibly one would want to add carbon fiber reinforcements to them and if they are biplanes you'd have to add diagonal reinforcing wires. These would be vehicles to prototype aircraft for human crews. The first vehicles would be used to move rovers and perhaps cargo to surface expeditions and would be relatively small (the size of Helios perhaps), but eventually you'd want to move to something that is "Twin Otter class" (one tonne of payload or six-seven people or a combination).
-- RobS
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You may find these others equally fascinating.
New Mars Eagle Has Flown, and Landed, in Oregon Test
http://www.space.com/busines....20.html
Mars Airplane Soars on Earth
http://www.space.com/busines....-1.html
Astronotes:
May 1
Proposed Mars Airplane Stretches Wings
NASA has ordered a full-scale prototype of a proposed Mars airplane. The craft is one of four concepts being considered as the first Scout mission to the red planet, slated for liftoff in 2007.
The Mars Scout Aerial Regional-Scale Environment Survey (ARES) mission involves flying the first airplane in another planetary atmosphere.
Aurora Flight Sciences Corporation of Manassas, Virginia is building the full-scale prototype aircraft. In addition to Aurora, the ARES team includes NASA Langley Research Center, the Jet Propulsion Laboratory, the Charles Stark Draper Laboratory and Lockheed Martin Astronautics.
The new Mars airplane is to be a full-scale version and will demonstrate flight-weight components. The prototype plane is scheduled to make its first flight later this year with a deployment test in the thin, upper reaches of the Earth's atmosphere - to mimic the aerodynamic regime of Mars.
Aurora Flight Sciences specializes in design and production of high-altitude unmanned air vehicles (UAVs) - part of an armada of high-tech equipment used in the recent Iraqi war.
Along with the airplane, an orbiter, an atmospheric sampling mission, and a polar lander are also being considered under the Mars Scout program. NASA will decide later this year which mission will head for Mars in 2007.
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Power for Mars planes: http://www.space-rockets.com/marsjet.html]rocket engine, thruster and turbojet
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What a pilot thinks: http://css.ca/marsaviation.htm]Aviation on Mars
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But the Martian Green Men will Fly:
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Great links the last one is in German I think but does not translate all that well. Some more flying saucers are further down the page are also interesting as well.
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http://www.spaceflightnow.com/news/n040 … s/]Article about Helios mishap report
*I checked the last pageful of posts and don't see this as having been posted already. But I started this thread so nyaaaaa. :;):
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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NASA Releases Helios Prototype Aircraft Mishap Report
http://www.spaceref.com/news/viewpr.html?pid=14958
Maybe the bow of the wings if the ends were connected together would have made for a different design but might not have seen the problem.
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Just another way to do aircarfts but a very interesting concept.
WHIRL-A-DRONE BEGINS TO SPIN
http://www.defensetech.org/archives/001098.html
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This is my vision of a reusable orbiter on Mars : While most of the orbiter itself ressembles the Space shuttle, the main difference is the wing parachute necessary to flight in the low atmospheric density.
The base is designed around a biodome, nothing unexpected here.
I don't think that we don't have any of the technology requested already, now.
A picture worths a thousands world : nothing look that much futuristic here. That's my point.
warning : 1) to see the gallery, registration (free) is needed. 2) some folks/artists post nudity in other pictures, but it's not porn. My gallery is mostly about Mars though.
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warning : 1) to see the gallery, registration (free) is needed. 2) some folks/artists post nudity in other pictures, but it's not porn. My gallery is mostly about Mars though.
*Monsieur, ne devrait pas avoir mentionné la nudité. Maintenant chacun regardera les photographies nues et non votre galerie de Mars!
(Mais pas je; Je suis une bonne fille!).
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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warning : 1) to see the gallery, registration (free) is needed. 2) some folks/artists post nudity in other pictures, but it's not porn. My gallery is mostly about Mars though.
*Monsieur, ne devrait pas avoir mentionné la nudité. Maintenant chacun regardera les photographies nues et non votre galerie de Mars!
(Mais pas je; Je suis une bonne fille!).
--Cindy
It just shows that Mars is not the only interesting universal topic.
I watch the nude picture sometimes, well, bof, a nude is a nude, then what ?
But you guys, better watch my Mars pictures (too) !
Good (well, understandable at least) french by the way Cindy.
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Well any plane flown romotely will require software writing. The NASA solicitation: MarsFlight Software Development
MarsFlight will enable users to fly a Mars Airplane near the surface of Mars to collect data on the Magnetic field that they can print out and analyze following the completion of their mission."
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Is there sufficient air pressure on Mars to even allow flight? If there is Would a Rover retrieving Zeppelin be the better choice?
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Mars Plane on Track for Test Flight
Engineers are building a full-scale test vehicle that is scheduled to make a high-altitude flight next year, said principal investigator Joel Levine, with NASA's Langley Research Center in Hampton, Va.
Taking wing in the thin Martian atmosphere will not be easy. The pressure on Mars is so low that even though the aircraft is being designed to fly a few thousand feet above the planet's surface, it would be the equivalent of flying more than 100,000 feet above Earth.
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An airplane on Mars will need predictive, realtime decision logic, to make up for the time-lag imposed upon chairborne operators back on Earth. I suggest--while that is being worked on--we send a number of aerostats to explore the "nap of Mars" from the air. Ignoring the buoyancy question for the moment, the idea proposed from time to time in these forums of a winched drag-line, has all the potential needed for time-lagged pilotage of airborne survey instrumentation-- even soil sampling, if a fly-by-wire "smart grapple" were to be included at the lower end.
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