Comment Re:Good for a lot of reasons... (Score 5, Informative) 186
>My question is why L2 and not L1?
Indeed, I have no clear idea, because once an object is located at one of the five Lagrangian points L1-5, very little energy is required to go to any other one.
L1 needs however the least delta-v to be reached from Earth or Moon, and direct radio communications are possible with L1 and L3, contrary to L2 which is hidden by the Moon from Earth. L3, on the side opposed to the Moon would require still a bit more delta-v than L2. L1-3 are dynamically unstable, so a station there would need periodic corrections.
L4 and L5 are more stable than L1 or L2 but require still a bit more delta-v wrt L1-3.
To reach Mars, or any escape from the Earth-Moon system L1_5 are almost equivalent if enough time is available, but L4-5 provide more orbit choice, so more possibilities to choose quick routes.
Note that the station would not need to be located precisely at one of the L1-5 points, but could be on so called halo orbits circling around such a point.