The idea is two-fold. For one, cheaper satellites means more satellites, which should eventually translate into satellites that are more responsive to troops on the ground. Right now, any old platoon in Afghanistan can't just call in a satellite to provide intel on the ground. That will change. And of course, there's those missiles. The military would like to make it cheaper, easier, and faster to put a satellite into orbit so if one gets shot down by an enemy force, another can quickly replace it. Make the satellites plentiful at a fraction of the cost of the missiles, and satellite warfare becomes uneconomical.