The Bristol Spaceplanes Spacecab was a Two Stage To Orbit (TSTO) Manned Spaceplane, with an airbreathing supersonic / hypersonic, delta winged first stage and a second stage powered by a liquid fuelled rocket engine. It was proposed by David Ashford of Bristol Spaceplanes Ltd. in the 1980`s / 1990's. The Concorde-sized spacecraft would deliver a payload of 6 persons to low Earth orbit. It would serve as a prototype for the larger 50-person Spacebus.