United Space Marines
You could call them space Terminators:
The prospect of deploying robots from near-orbit was perhaps unthinkable when Sustain was first conceived in 2002. But in the development of military automatons, a few years is a long time. Between 2002 and 2009 the Pentagon expanded its robot force by two orders of magnitude. New robots were smarter, tougher, more diverse, more affordable, and more likely candidates for sub-orbital deployment.On the land, in the sea, and in space...
Robotics solved Sustain's most intractable problem. Early studies of the Sustain concept, sponsored by the Marines' Space Integration Branch, kept running into the same brick walls. The space tourism industry was quickly proving the concept of an affordable, two-stage, sub-orbital transport. And according to Worden, "it's just a scaled-up version of that, that would do this [Sustain] mission."