multiple launch moon mission vs. Single Launch moon missions

If the mission is assembled from major, independent and
self-sustaining elements in LEO (say 8 of them for purposes of
argument) and one of the launches fails, then you have 7 of the pieces
successfully in a parking orbit. One additional launch, with a spare,
and the mission could continue. This an example of an anomaly that can
be handled and the mission still completed, rather than a failure.


Why LEO? Your throwing away one of the major advantages of a multiple launch
Lunar Mission. Popular Science has an article about a possible Lunar Mission.
the mission is launched with a Shuttle-C like configuration. Each Shuttle-C can
lift half as much as the old Saturn V, so it counts as a multiple launch Lunar
Mission. The shuttle-C has a rocket engine at it's base, in this case an RS-68,
that feeds from the External Tank. Once the external tank is emptied, the RS-68
and the External tank is ejected, and underneath is an RL-10 engine that boosts
the rest of the ship plus 6 astronauts to Lunar Orbit. Another Shuttle-C boosts
a fuel tank for the lander, which the 6 astronauts are in, into Lunar Orbit.
The lunar lander portion docks with the fuel tank and ignites its engines
using residual fuel. the acceleration causes fuel from the docked tank to pour
into the Lunar Lander, and when the tank is emptied. the lunar lander cuts its
engines, ejects the tank, and restarts its engines so it can land on the Moon.
Each portion of the Lunar mission flies to the Moon separately and no attempt
is made to construct a larger engine in Low Earth orbit. The unmanned parts of
the mission might even be propelled by a nuclear-electric ion engine instead of
an RL-10, where it could take a month to reach the Moon rather than 3 days.
Astronauts need to get to the Moon quickly however lest they needlessly use up
their consumables. So the bulk freight can used high efficiency rockets while
the Astronaut module uses chemical rockets to get to the Moon.

Tom