US Small Unit Space Transport and Insertion

Elite Squad any place of Earth within 2 hours. The Small Unit Space Transport and Insertion (SUSTAIN) is a transport spacecraft for a dozen of U.S. Marine Corps. In the first stage it is carried by a large aircraft like B-52 to high altitude then the second stage is to fly up to Mach 7 powered by its own scramjet engines.
More: http://en.wikipedia.org/wiki/SUSTAIN_(military)