Direction of LL docking to CM | Lunar lander design | Forum

Just a quick thought: all of our concept art so far has shown the LL docking to the CM in such a direction that the chair is facing "forward" (i.e. in the direction of CM travel), with the LL engine pointed at the CM.  I propose that we in fact invert this arrangement, for two reasons:

1. It puts the chair closer to the CM, making the EVA transfer shorter and hence safer.
2. It means that the LL engine is pointed in the correct direction for the Descent Orbit Injection (DOI) burn, eliminating the need for a 180 degree rotation and hence saving on RCS propellant.

On point 2, one may argue that the 180 degree turn is required during docking after ascent (this is apparent if one thinks briefly about the situation), but note that:

1. The lander will be substantially less massive at that time, due to empty fuel tanks.
2. We may be able to get away with not actually docking the LL back to the CM in exactly the same position as it started, eliminating the need for the turn at all.

Are there any objections to this?