Summary
A classified program begun in 1982 to determine the technical feasibility of a military aerospace plane. Requirements were for a sled-launched horizontal-takeoff / horizontal-landing single stage to orbit (SSTO) launch vehicle powered by a modified SSME with a two-position nozzle. Dry mass was to be 100,000-150,000 lb, takeoff mass 1,2-1,5 million lb with a 10,000 lb payload to a polar orbit from Grand Forks AFB. AMSC concepts from Boeing, Lockheed and McDonnell Douglas were hand-picked for further development with Rocketdyne and Air Products as propulsion contractors. The Boeing concept was apparently their RASV vehicle. The McDonnell Douglas proposal, possibly GRM-29A, had a down- pointing SSME in the nose to cater for the runway requirements, whereas Lockheed used a ramped takeoff with two solid boosters. By 1984 it had become clear that horizontal takeoff was inappropriate use of rocket power, and the program was superseded by Science Realm.
Sources
http://www.secretprojects.co.uk/forum/index.php/topic,315.0/all.html