Rand Simberg wrote:
On 17 Feb 2006 12:17:26 -0800, in a place far, far away, "Will McLean"
made the phosphor on my monitor glow in such a
way as to indicate that:

How practical is it to tailor a parking orbit for lunar missions that
is reasonably efficent to reach from KSC and precesses at 180 degrees a
lunar month?

What's wrong with 360?


Nothing. Any multiple of 180 will do. 180 seemed more doable, based on
the orbits I've been able to find information on.

Oh, I misunderstood. You're looking for an actual precession in an
inertial frame? I thought you meant an apparent precession from the
viewpoint of the earth. How does 180 help you? I would think that
360 would be the only one that would give you constant angle with
respect to the earth.


D'oh!. I meant to say 180 degrees in half a lunar month, or 360 a
month. Or any multiple of that, since I don't require a constant angle
with respect to to the system. I want to arrange the precession so that
every time the lauch window opens to a particular lunar orbit, the moon
is in the plane of the parking orbit.

Anyway, what's wrong with L1, other than the performance hit (a
penalty I think well worth paying)?


Performance hit, the travel time, and L1 is no longer an option with
the current plan.

Will McLean