subject: Realities of Space: Science of Real Space Battles [print this page] It's not terribly expensive or difficult, comparatively speaking, to get people from orbit down to a planet surface. You fall. This is the purpose of a space capsule. What's really, really, prohibitively difficult is getting them back up again. So, the victorious orbital forces would have to bring in a transport ship chock full of Space Marines and drop them all at once in little capsules (little because they can only be so big for the atmosphere to effectively brake them, and because you don't want all your Marines perishing in some unfortunate incident). Some orbital forces would remain in place to threaten the ground with bombardment and give the Marines a bit more muscle, but really, the ground-pounders are going to have to be pretty self-sufficient. If they ever want to come back up, they would have to build and/or fuel their own ascent vehicle. (This is the problem facing any NASA Mars efforts, too: getting back up through the Martian atmosphere is much harder than any of the lunar ascents were.)
