Tom Cuddihy wrote:

kert wrote:
So why exactly is launching six astronauts in one vehicle better than
launching three astronauts in two vehicles at the same time ? Since
when has putting all eggs in one basket, or launcher in this case,
become a wise practice ?

-kert

Congress has made it pretty clear during the past two shuttle
explosions that loss of astronaut life is NOT acceptable. If one of the
two four person launches failed, ALL missions would be on hold.

Just think about it. If you launch two three person crews to orbit,
where they have to transfer to a 6-person lunar CEV, you need to have
launched 3 vehicles to LEO just to get the crew in a CEV. IF each of
the four person CXVs is 15 tons, and the lunar CEV is still 30 tons,
you still have to launch 60 tons to LEO to get the passengers into a 30
ton CEV. If, on the other hand, you launch one 30 ton CEV, it can be
launched from earth with all the passegers on board. Doesn't that make
a lot more sense?

Another possibility: For longer missions, launch two four-man CEV's
with three aboard each, dock them to each other in orbit, then operate
them as a dual-redundant unit with a bit of extra elbow room.

Which eliminates the need to fly a six-man CEV with attendant new
larger-than-EELV-heavy booster every time you rotate Station crew.
(Might as well still be flying Shuttle; it'll end up costing about
as much per flight.)

Henry