Quite simply, we need to give the Military a reason to get into space. Private Industry has no incentive at the moment, and the Military can't be as bad as NASA has been. A Space Cruiser, with shuttlecraft for traveling to and from the planet's surface would be huge.
Even if it's only armed with Cruise Missiles, It can still be a formidable force to reckon with. imagine a Cruiser sitting over Iraq right now. Terrorists plant a roadside bomb, the Cruiser should be able to go back through its logs, find who planted it, trace them back to their house, and drop a Tomahawk on the house. The limitation with Spy Satellites is that you can only get a look for a limited time, while the satellite passes over head. But with the Cruiser, since it's there the whole time, the only thing you have to worry about, is cloud cover, and even then if you put a good enough science package on the ship, you should be able to track them through other means.
The Miliitary needs to just ignore Greenpeace and the other enviromental whack-jobs, and put a Fission powered ship in orbit. It's not going to blow up and destroy the world.
The Cruiser can perform non-military missions as well, Outpost construction, planetary surveys. Almost all the technology is already available, the most difficult part would be getting the thing into orbit. Make the ship with some modular components and it can be upgraded as our technology advances. Develop a cost effective Laser/Particle Cannon, Fusion Power plants, Artificial Gravity, Impulse Technology, etc..
But certainly, the Military is going to HAVE to be the ones doing it, the technology wont advance until we're up there, and the Private sector won't go up until the Techonolgy advances...I guess we need another JFK...