AIUI (I'm no expert, someone will no doubt correct me if I'm wrong), the L2 Lagrange point is not stable. If you were perfectly at the L2 point the forces would

AIUI (I'm no expert, someone will no doubt correct me if I'm wrong), the L2 Lagrange point is not stable. If you were perfectly at the L2 point the forces would be balanced and you'd stay there, but you'd have to perfectly at that point with zero perturbations, which is impossible. It's like standing a sharp pencil on its tip - the slightest disturbance causes an accelerating fall, so it always falls. In the case of L2 any object placed there will always drift away with accelerating velocity. To counteract this you need thrust, and that needs reaction mass. You can't do it with gyros etc, you have to chuck something out in the opposite direction to the way you want to push. Edit: Incidentally (again not an expert) this sounds like maybe a useful quality of L2. L4 and L5 are stable which I assume means they're filled up with space garbage and odd socks, which maybe would be a problem for putting things there?