On 11 Aug 2005 09:36:16 -0700, "TVDad Jim" wrote:


What are the risks of having an unpiloted CEV in orbit, rather than
leaving a pilot onboard while the LSAM lands?

Somewhat higher, I suppose. Especially in lunar orbit with no magnetic
field to protect electronics from solar flares and what-not.

How have these risks changed since the days of manned lunar CSMs? Is it
just better automation available? Was having a CMP onboard just a
"consolation prize" in case the LM didn't make it back for a LOR?

No, even human piloted dockings were new and risky at the time of
Apollo (only, what... five or six dockings before Apollo 9?) and
automatic dockings were way beyond the state of the art at the time.
So one astronaut stayed behind to run the CSM.

Not so today, although NASA has yet to achieve it. We'll need
autodocking anyway for the unmanned cargo version of CEV.

How do four astronauts on the Moon make it a "better" mission than
three astronauts on the Moon?

Four crew on the surface means you can have two outside pretty much
all "day" except during crew sleep. Double the productivity versus two
man or even three man, as 16 hours is too long for one person to be in
a spacesuit outside, and safety will call for at least two astronauts
outside at a time (spacewalks are always at least 2 people, too.)

Brian