Mars "Reference Mission" illustrated

"Elden" wrote in message thlink.net...
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In article ,
h (Rand Simberg) wrote:
That's because cars require much higher power than planetary rovers.
The latter don't require high speed, or acceleration.

Although this is true, it may be irrelevant here. The vehicle that is
depicted here is _big_. Not only would the solar power have to provide life
support, heat, electronics, etc., but it also has to move that vehicle
around. Even if the top speed is only a few miles per hour, it is a
sizeable vehicle. Add to that the fact that one of the illustrations shows
it pulling around the hab vehicle, and that increases the power
requirements.

There's no reasonable chance of a manned vehicle being
actually "Solar Powered" directly, even on Mars. It's
going to have to be battery powered and recharged by
Solar power. And, actually, that could make quite a lot
of sense on Mars, there need not even be Solar Panels on
the rover except as backup (which is always a good idea).
On Earth, battery powered cars are actually feasible,
and can travel long distances at reasonably high speeds
carrying reasonably heavy loads. However, they are
vastly inferior to internal combustion powered
automobiles so they are at best niche equipment. But
on Mars ordinary IC engines won't work, and similar
systems have various difficulties in operation.
Personally, I think the CH4 powered engines in the
Mars Direct plan are a really, really good idea, but
they are not the only option. Additionally, the
reduced gravity of Mars would improve the performance
of a battery powered car (reducing the effective
weight of the chassis and batteries). Especially
since a Mars manned rover is going to be "heavy"
by Earth standards (pressurized, large interior
volume to fit suited astronauts, etc.) the
additional weight of batteries won't make all that
much difference.

So, you outfit your rover with batteries, make sure
it has a decent range off the batteries, and slap
some PV cells on the roof to allow it to recharge
or slow crawl, just in case. Actually, such a
rover would have an unlimited range, provided the
crew could be kept alive.

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In article ,
(Christopher M. Jones) wrote:

There's no reasonable chance of a manned vehicle being
actually "Solar Powered" directly, even on Mars. It's
going to have to be battery powered and recharged by
Solar power. And, actually, that could make quite a lot

NASA considers solar power requirements to be one of the big limitations of
the current MER rovers and is considering nuclear power for future rovers.





Elden