SABRE engine designed for Skylon spaceplane, 1990s.
© Science Museum / Science & Society Picture Library
Scale model. Skylon is a British design for an unmanned Single Stage to Orbit (sTO) spaceplane designed to reach Earth orbit where it would deploy and retrieve satellites. It was intended to be completely reusable, with the objective of cutting the cost of launches dramatically. It was envisaged that some 30 Skylon vehicles would be built, and operated by commercial companies, and it was planned that Skylon could be adapted for carrying pasengers, or 'space tourists'. At the heart of the Skylon concept were its two innovatory Synergestic Air Breathing and Rocket Engines (SABREs) which were designed to draw oxygen directly from the atmosphere. Skylon is one example of several sTO launcher concepts considered worldwide in the 1990s.