Just idle speculation on a winter afternoon here but there have been several
scientific papers lately that suggest some interesting possibilities for
flight on Mars.

If, as many suspect, there was once large amounts of standing water on Mars,
the atmospheric pressure to maintain that water must have been in the 600 -
1000mb range. Recent data from the Mars Reconosance Orbiter suggests that
the current rate of atmosphere loss doesn't support the near total loss of
that atmosphere since so it may still be there somewhere - possibly frozen
and covered by dust.

Other papers suggesting ways to "teraform" mars hold that a small amount of
CFC gasses (posibly carried by as few as 10 rockets) could trigger enough
greenhouse effect to release that frozen atmosphere should it prove to be
there. CFC's are thousands of times more powerful as greehouse gases than
CO2. There is a lot of oxygen on Mars but it's mostly bound up with iron as
rust (That's why Mars is red) However enough of it may be loosely bound to
minerals that 200mb or so of it would be released if warmed.

So, still speculating, at 38% Earth gravity and with an Earth-like1000mb
atmosphere, what would flight be like on Mars? Well, it might be possible
for humans to routinely fly under their own power. It would take only a
third as much wing area for the same wing loading.

Interesting stuff...

Bill Daniels


"Ron Wanttaja" wrote in message
...
On Sun, 11 Feb 2007 14:21:41 +0000, Scott wrote:

DABEAR wrote:
It would seem to me that if there were enough atmosphere on Mars to
support Ultralights, an astronaut could cover greater ground in
exploration, especially considering the STOL capability of such an
aircraft. VTOL is nice, but an engine failure could cause a mission
abort. A dual engine failure could maroon astronauts. In regards to
the rovers, if the vehicle breaks down, it's a long way to walk back
to base camp on very little oxygen.

Good idea, but they don't have any VORs there yet.

Yeah, but on the plus side, there's no FAA there, either. :-)

A couple of problems. First, Mars' gravity is about 38% of Earth's, but
its
atmospheric density is less than 1% of ours. You'll end up needing a very
large
wing to carry an astronaut, especially when you consider that our intrepid
Mars
explorer has to wear a pressure suit and carry sufficient air for his
sojourn.
Plus the fact that the air is so thin the vehicle's engine probably won't
be
able to use it to oxidize the fuel, so the vehicle must carry both fuel
and
oxidizer.

The whole problem isn't THAT much different from the "Lunar Buggy"
discussion we
had about two years back. Here's one of my write-ups on that:

http://tinyurl.com/2kwjhe

Ron Wanttaja