The cutting edge in Black Horse development is now at :
The Black Horse is a proposed design for a single stage to orbit, reusable launch vehicle. The primary investigator for the Black Horse was Mitchell Burnside Clapp. Although originally concieved as a military vehicle developed for the United States Air Force, political realities make it unlikely that the USAF will ever actually build the vehicle.
The key idea behind the Black Horse is that it can be aerially `refueled' from a tanker such as the USAF KC-135. This has caused some people to describe it as `stage-and-a-half' rather than a true SSTO vehicle. It will take off and land horizontally from a runway, and will be piloted by human pilots. Two demonstration vehicles were planned as stepping stones to the Black Horse, called the Black Foal and the Black Colt. The Foal would demonstrate aspects of the technology and provide proof of concept. The Colt would fly to half orbital velocity and utilize an off-the-shelf `kick-stage' to put satellites in orbit.