At an astronomy meeting this evening, I obtained a
bit of met data about Mars. Not sure as to how accurate
this all is.
The day (sol) is 24.5 hours long.
The atmospheric pressure is about 6 millibar on the
plains, increasing to a maximum of 10 millibars in
some of the basins such as the Hellas Basin. The pressure
falls off rapidly and is probably negligible in the
highlands and at the top of Olympus Mons.
On the equator the temperature varies between around
+10 centigrade at midday down to maybe -40 centigrade
at night. However this is the surface temperature.
At 2 feet the temperature falls to 0 centigrade, and
at 4-5 feet the temperature is down to -20 centigrade.
Winds have been measured at around 50-60 mph. There
are large scale atmospheric events such as duststorms
which can be global in extent. There are also thought
to be 'dust devils' which are similar in profile to
tornados but which extend up to 30,000ft.
There are clouds which may be water at 15 miles and
carbon dioxide at upto 25 miles.
Mars is about 1/10 the mass of the earth.
There are some ridge features available. Many craters
have ridges about 300ft high at the top. There are
also dunes and step effects with heights of 6-30 feet.
There is a very large valley, Mariner valley which
is much bigger than the rift valley.
Around the base of Mons Olympus there is a ridge which
is four miles high.
There can be carbon dioxide fogs in the Hellas basin.

Wilst the earth year is 365 days, the earth is 93 million
miles from the sun and this distance only varies by
about 4 million miles. However on Mars the distance
to the sun is around 120 million miles at the closest
but over 150 million miles at the furthest.

So the possible gliding conditions appear to be:

Ridge running on Olympus Mons - 4 mile high ridge,
pressure 2-4 millibar, temp around -20 to -60 centigrade,
wind 20-100 knots.

IMC climbs in small very tight dust devils - practice
in tornados first. Probably significant G-force/stress
issues!

Thermal flying - pressure 2-8 millibar, temp around
-60 to +10 centigrade, height range 3-30 ft, flight
time 6-10 hours. This would probably be quite difficult
to achieve as long wingspans would not be compatible
with steep banking at a few feet.

Straight downhill glides at very shallow angles (LD
may need to be several 100 or 1000) from the top of
the Hellas basin, or across/along the Mariner 'rift'
valley.

Thus I think the glider would need to fly in very low
atmospheric pressure of 0.1 to 10 millibars, in a temperature
range of -80 to +20 centigrade. It would need to be
strong enough not to break up in the local dust devils.
Have an excellent LD and possibly very small wingspan.

I suspect that we will need to sort out our local stratospheric
soaring before we can build a glider to fly successfully
in these conditions.

Rory O'Conor