In his preface to Spaceflight Revolution, David Ashford recalls how he started his research into rocket motors. As he later explains, these were motors that would power a space plane — one that would launch space travellers and satellites cheaply and reliably into orbit. That was 1961. Ashford admits he would probably have taken another job if he’d known that, 42 years later, satellites would still be launched by rockets descended from ballistic missiles. The technology is there, but political and budgetary decisions have so far stopped space planes getting off the ground. But Ashford presents a compelling argument that a small orbital space plane would cost relatively little to design and develop — the equivalent of just two shuttle flights.