The Space Review: Review: HOTOL and Skylon

Those two concepts were among the most ambitious designs for spaceplanes proposed during the Space Age: vehicles that would take off from a runway (perhaps with assistance from a rocket sled) and fly into space using an advanced engine design that started as an air breather and transitioned to a conventional rocket engine at higher altitudes. The designs promised to significantly reduce the amount of propellant the vehicle had to carry, since it could use atmospheric oxygen while in the lower atmosphere, while offering aircraft-like operations with lower costs and more frequent flights.

The new book HOTOL & Skylon: The Story of Britain’s Spaceplanes by Rob Coppinger, editor of the British Interplanetary Society’s SpaceFlight magazine, offers a detailed history of these two decades-long efforts that attracted considerable publicity but never got close to actually taking off.