U.S. Air Force Reusable Space Shuttle: The Triamese by Convair

Triamese reusable space transportation system has attractive operational capability and significantly reduced operational cost, The concept has been named Triamese, since it uses three virtually identical elements to deliver its payload to orbit, Each element is a rocket powered, vertical takeoff, horizontal landing, reusable vehicle. Good subsonic performance, attained by variable geometry wings, coupled with the use of turbofan engines provides a cruise capability which enhances both operational and logistics activities. Two of the vehicle elements operate as boosters from liftoff to a staging velocity of about 8,000 - fps, after which they decelerate and fly subsonically to a suitable landing site. The orbital elements, complete with payload, then accelerates to low earth orbit. Prior to staging, the rocket engines of all three elements are operating with propellants from the booster elements.