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Flying on Mars
jimharris submitted a bunch of links about flying on Mars: "X-Plane's author Austin Meyer is working out the details of flying on Mars. Meyer has taken his system and adapted it for the conditions on Mars and has discovered a lot about what it would take to fly on Mars, where the atmospheric pressure is 1 percent of Earth, and gravity one third, but laws of flight remain the same. Flying becomes difficult, and landing almost impossible. Other people are working with NASA to create Entomopters engineered to meet Mars conditions. More ideas about the concept can be found at PBS's Scientific American Frontiers. A quick search at Google will reveal many people are thinking about flying on Mars." It's a beautiful challenge - how to fly in a situation where everything you "know" about flight is wrong.
Well, if there is a game with accurate physics, it would be X-plane. Heck, with this game, you can even land the space shuttle.
The only problem is that right now, we don't have anywhere close to enough data for the other planets. On mars, we got lucky because NASA released all of their data from the explorer.
-- Dan
Helicopters won't work well on mars, you'll need to have your props spinning 10 times faster to get the same lift, which will be somewhat diffucult, no?
It might work actually, but AFAIK there aren't any easily manufacturable materials that will stand up to the centripetal forces, since there will be 100 times as much force on the end of the prop (centripetal force is the square of velocity). You might be able to do this by increasing the surface area of the prop (longer blades, or more blades).
Also, nasa's probes once they get into the atmosphere still use parachutes and rockets to slow down to a decent speed and then giant inflatable bubbles to bounce along, but you only use that when you're below a few hundred knots. In the article, it says, that you'll be going 400 mph in a well designed plane, there's no way you're gonna just bounce around if you hit the ground like that... Same inertia, right? imagine that its like having 10 times more inertia...
also, I've seen a few articles, he mentions red sky on mars.
I've seen no good proof to believe the sky is red, if its because the ground is red, think about the earth, in the middle of a desert, or forest, is the sky yellow or green? looking at that, you'll often think they'll be bluer than at the beach (where it tends to look grey, I live at a beach town).
Because the colour of the sky is caused by Raleigh scattering (or other scattering effects), the effect (based on the size distribution of particles in the atmosphere) is the same on Mars as it is Earth.
Somewhere, if you hunt around for photos from the surface of mars, and correct using say, photoshop, for the colour (look at the parts of the probe you can see in the picture and return them to their original colours, usually white or metal, unless its an american flag), the sky will be blue.
Disclaimer:The "Human" attached to this account is unresponsible for anything unless it wants responsibility.
what the hell are you all talking about? X-Plane has included a Mars environment for about a year. You needn't hack anything, Mr Meyer will help you out.
That was classic intercourse!
Same laws apply.. sure there is less of an atmosphere.. but you also have one third the gravity to contend with. The main problem with such craft on the martian surface would be the fact that 1) they are huge, and 2) they are light. With the storms that have been witnessed on mars recently, storing such a craft would be a nightmare if you didn't collapse it and store it. Lets not forget the possibility you COULD be in the air when such a storm kicks up.. nothing could save your arse if that happened..
.38g gravity of of Mars really helps - landing vertically should be a cinch.
Fortunately, the laws of rocketry also continue to apply. The
As for structural lightness, remember, the air is very thin. What looks like a huge storm on a satellite photo just isn't going to going to blow anything over on the ground. It's true, Martian winds can pick up small particles, and researchers are still trying to figure out how that happens - vortices maybe, and the oarger particles probably don't get very far off the ground. Global dust storms would contain only the finest particles.
Blimps/dirigibles on the other hand... with less than 1% atmosphere, you have less than 1% of the bouyancy. In the end your balloon will have to be 30 times bigger to lift the same mass. This means that, while a balloon might work, a dirigible won't. Too much structure required.
Life's a bitch but somebody's gotta do it.
Wouldn't helicopters work best on mars? Mars is smaller (I forget by how much).. so I doubt anyone's gonna need a 747 up there any time soon :P
RTFA. The basic problem is that you indicated airspeed is 1/10th the acutal airspeed, which means that your lift is 1/10th what it would be if you were on earth.
So of your main rotor is moving at a very conservative 200RPM providing enough lift for takeoff, then that same rotor would have to move at 20,000RPM in order to take off on Mars. This won't work very well because it will be very inefficient and probably make it difficult to keep the body of the helicopter stable.
Designing a helicopter to fly on mars would be a very interesting and difficult task indeed.
LedgerSMB: Open source Accounting/ERP
Blimps/dirigibles on the other hand... with less than 1% atmosphere, you have less than 1% of the bouyancy. In the end your balloon will have to be 30 times bigger to lift the same mass. This means that, while a balloon might work, a dirigible won't. Too much structure required.
On the contrary.... here's a little math..
Size of balloon for dirigible (and volume..)
Volume of ellipsoid (a=semimajor, b= semimean, and c=semiminor axes) = (4/3)*pi*abc.
A=100m B=40m C=30m
V=5.03x10^5 M^3
V=5.03x10^8 L
Now for temperature and pressure...
Assuming Tmars to be avg. -50C = 223K
And assuming we inflate to 2atm(mars) = 0.02atm(earth)
PV = nRT
n = PV/RT = (0.02atm * 5.03 x10^8 L) / (0.0821 L atm/mol K * 223 K)
n = 2.75x10^5 moles within balloon...
M(H2)=2 g/mol * n = 5.5x10^5 grams
yeah, that's a LOT of hydrogen.. but lets continue
For the atmosphere this hydrogen is displacing...
Which, BTW, is over 95% CO2, unlike earth which has a much lighter atmosphere for a given pressure..
PV = nRT
n = PV/RT = (0.01atm * 5.03x10^8 L) / (0.0821 L arm/mol K * 223 K)
n = 1.38x10^5 moles of atmoshpere displaced
M(CO2)=44 g/mol * n = 1.21x10^7 grams
Taking the difference, we find that there is 115.5x10^5 grams or...
11550 kg of lifting force here...
Of course we might need to put more H2 into the balloon to have it hold it's shape.. for each martian atmosphere of additional pressure we inflate the craft with, go ahead and reduce the lift by 275 kilograms. Double the local atmospheric pressure should be sufficient.
Now, can we build an airship of that size and keep it's weight under 10000 kg?
(Mind you that IS 30000kg here on earth)...
I think it is safe to say it is more than easily accomplished.
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. echo -e \\04 >
You're thinking rocket engines.
:)
Rockets carry their own fuel and as such provide their own thrust.
Jets and props require an atmosphere to provide the gas necessary to provide thrust.
Sorta like... imagine outboard motors and water jets out of the water... not much thrust
GPL Deconstructed
Fortuna Wolf said:
Somewhere, if you hunt around for photos from the surface of mars, and correct using say, photoshop, for the colour (look at the parts of the probe you can see in the picture and return them to their original colours, usually white or metal, unless its an american flag), the sky will be blue.
In spite of this potential troll, I feel compelled to point out that the reflectivity of a surface will naturally reflect most electromagnetic components of its environment. This goes for white surfaces. So by "correcting" the color balance of such a surface, such as appendages of the mars probes, you have in fact only inferred the original environment from which your photo was based.
Mojotoad
I hate to nitpick, but this is so wrong I had to point it out.
...
;)
10000kg on earth is still 10000kg on mars.
Taking the difference, we find that there is 115.5x10^5 grams or...
11550 kg of lifting force here..
Now, can we build an airship of that size and keep it's weight under 10000 kg? (Mind you that IS 30000kg here on earth)...
I'll assume based on the rest of the post that you know the difference between mass and weight...
Other than that and the fact that some of the calculations you show have the wrong answer (but strangely the right final answer, where'd you pull that out of?), you're right, a blimp should work ok on mars.