John Lear's Moon Pictures on ATS, page 160

Originally posted by zorgon
Exhibit B: The Mars Flyer

A little while back (in the Mars thread)we were discussing clouds and a "thin" Atmosphere on Mars...

Here now is ABSOLUTE PROOF that SOMEONE knows how thick the atmosphere on Mars really is...I mean after all, don't you need quite a bit of AIR to fly an airplane?

AFRL Tests Mars Flyer Concept

Well the definition of "AIR" really refers to the stuff we breathe here on planet Earth. Mars does have an "ATMOSPHERE". It is fully admitted and documented (even by NASA). It is not a secret! But to say its "air" is not necc. correct if you adhere to the common definition that we refer to AIR as...

Definitions of "AIR":

a mixture of gases (especially oxygen) required for BREATHING; the stuff that the wind consists of; "air pollution"; "a smell of chemicals in the air"; "open a window and let in some air"; "I need some fresh air"

Mixture of gases which composes the Earth's atmosphere.
www.palmbeachdailynews.com...

Etc etc... so in any case, I believe the term to use should be "ATMOSPHERE" to be correct, but hey if you want to use "AIR" feel free.

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The composition of Mars atmosphere:

95.32% carbon dioxide
2.7% nitrogen
1.6% argon
0.13% oxygen
0.07% carbon monoxide
0.03% water vapor
trace neon, krypton, xenon, ozone, methane
_______________________________________________________________

The average surface pressure on Mars to be 0.7% as compared to Earth. The average height of features on mars is much higher though, so the corrections need to be applied when comparing the atmospheric pressures to that of Earths. Taking the sea level pressures on Mars and comparing to that of Earths would be a better count as to the comparison...With this it works out to be around 1.1% to that of Earths atmospheric pressure.

Now on Earth the air pressure at 40000 feet is around 13% of the sea level pressure, so thinner than at sea level of course, but not nearly as thin as on Mars. Density also needs to be looked at in the Mars atmosphere since the constituent gases that make up the atmosphere are different.

Aerodynamic forces directly depend on the gas density. The mars atmosphere model gives us two eqns, temperature and pressure:

T = -10.34 - 0.001217(h)
p = 14.62 (exp(-.00003(h)))

and density:
r = p / [1149 (T + 459.7)]

T=temp, h=altitude, p=pressure, r=density
note: there are two different models for the calculations w.r.t altitude. The above is altitude above 22000 feet models...

So with these eqns, it can be worked out that the pressure at say 100,000 feet on Mars is around 3% to that on Earth. The temperature on Mars at this altitude is -132F compared to Earth's -40F. So the Martian atmosphere is 'closer' to that of Earths relative to being able to aerodynamically support an airplane.

The mars atmosphere CAN support aerodynamic flight, ie: the airplane won't just "fall from the sky", the flight will NOT be able to be sustained for long periods of time based upon the wing area being a feasible amount. So thus with a feasible wing area (for a scientific Mars exploration mission) the airplane will not be a sustained flight, but a shorter flight, basically a probe similar to the crash landing type probes, but with a relatively longer observance time of the planet.

Here is some info I've found on the particular project:

mars.jpl.nasa.gov...
Because the Martian atmosphere is so thin, taking off from the ground would require very big wings or a very fast take-off. One solution to this problem is to have the airplane drop off an entry vehicle as it is coming into the Martian sky. As the plane drops off, the wings would unfold and it would start flying, being powered either by batteries or by gliding through the air. A likely place to fly airplanes would be in valleys or other interesting places where there is a lot to see over great distances.

Although this flight would be relatively short, less than an hour, and shorter than a balloon flight for example, an airplane is more controllable and can be directed to closely approach targets of interest. To receive even more data from an airplane, engineers are also engaged in further research that will give them insight into how to make a Mars airplane stay aloft for longer periods of time.

The ARES Model

The unfolding sequence, it is NOT designed to stay aloft for an extended amount of time. A sort of kamikaze mission, stay aloft for short amount of time, but be able to perform data gathering at certain altitudes aver certain areas of study, finally gliding down and either no longer function, or if lucky, some limited amount of data gathering available.

You can build your own ARES!
marsairplane.larc.nasa.gov...
marsairplane.larc.nasa.gov...

[edit on 3-6-2007 by greatlakes]

The Mars-1 Humvee Rover Project