The tests, which will be conducted with a Boeing-built scale model of a winged spacecraft design, will be conducted in October by use of a Sikorsky helicopter as the inert, unmanned craft's carrier vehicle. The plan is to release the mini-spaceplane vehicle from beneath the chopper and allow the craft to perform landing operations. The tests come as the Air Force is refining mission roles and potential applications for fleets of reusable military spacecraft that would carry Air Force pilots and military satellites into space from a normal hard surface runway at any Air Force air base. While the spaceplane tests are to be conducted, the Air Force will issue a series of study contracts this fall to bring the concept further along. But Pentagon sources have told SpaceCast that the senior Air Force leadership is not yet ready to take the next step: requesting development funds, which could run into the hundreds of millions just for spacecraft prototypes.

Boeing, McDonnell Douglas (soon to be a Boeing subsidiary), and Lockheed Martin will be bidding varied space vehicle designs as candidates for additional Air Force study. McDonnell Douglas is proposing a version of its wingless DC-X ballistic rocket technology demonstrator. Lockheed officials have confirmed they are proposing a military version of the NASA X-33 test craft. All designs would carry a single pilot and a small payload bay on a vehicle that would not actually orbit the Earth. Instead a new upper stage rocket - also under Air Force design at the Phillips Laboratory in Albuquerque N.M.- would fly the last way from the spaceplane's lower altitude into final orbit.

In addition to the obstacles offered by budget restrictions and technology research, the military spaceplane idea also faces a geopolitical one: several Capitol Hill sources have said that the existence of such a system could act as a weapons carrier -in violation of the existing U.S. and Russian arms control agreements, since the spaceplane's "payload" could easily be a nuclear warhead.