Jonathan Silverlight wrote:
In message , Sea Wasp
writes

Kleopatra44 wrote:

You can come home if thing's turn out bad on the moon. You can't do
that from Mars :-(


Um, why do you think that you could do the one and not the
other? Any expedition sent to either place would be designed for
return capability. If "something went wrong", which place would be
better depends on what the "something" is.

Don't think of the Moon as somehow being a hop,skip, and a jump.
It's still a hell of a long way away through a hell of a lot of vacuum.

It _is_ a hop compared to Mars.
If you had the means, you could at least rescue the crew if something
went wrong on the Moon that didn't totally destroy the ship.. "Mission
to Mars" notwithstanding, anyone on Mars is on their own.

Not really. In both cases the only situation in which EITHER would
permit a "rescue" after "something" went wrong is if they had
sufficient material to survive long enough for a rescue mission. This
means sufficient reserve for them to survive being marooned for the
length of time it would take for a rescue mission to be mounted.

In BOTH cases, you clearly have the technology to reach the target.
In BOTH cases, you clearly know the planned duration of the mission.
In BOTH cases, you would have to have some reserve, X, available and
planned for.

In BOTH cases, the space mission would be planned using the same
physics limiting assumptions. If you assume the Moon mission brings a
survivable reserve, the Mars mission would too.

In BOTH cases, based on prior missions, there would NOT be such a
reserve, and there would NOT be anyone standing by to rescue you. See
"Apollo 13". They had to either solve the problems themselves, right
there, or die. You're not one of the people that thinks the Space
Shuttle could have gone to the Space Station and waited for rescue,
are you?

--
Sea Wasp
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