It was a Space Shuttle with a mission - to drop a weapon payload anywhere on Earth and to do so while approaching its target at hypersonic velocity - 18,000 miles per hour. Between 1957 and 1963 the Dyna-Soar program consumed430 million of the US taxpayer's money. However, it never flew. Cancelled less than two weeks after President Kennedy's assassination, the Dyna-Soar (or X-20) was consigned to oblivion by the stroke of a pen. For the first time this book compiles many of the critical government documents that tell the story of America's extraordinary lost opportunity.