The Air Force officer who has plummeted 20 miles down through space to prove the possibility of parachuting from stratospheric planes and rockets, tells his story with the aid of a popular aviation writer. ""Project Excelsior"" was the name given the series of fantastic, nearly-fatal experiments in parachute jumping from great heights. Captain Kittinger, an Air Force test pilot and survivor of a real emergency ""bail out"" from a jet in 1957, was the man chosen for the testing. Telling his life story briefly, he also gives some accounting of the history of long jumps, the medical and scientific data involved, and the risks which go with such a dangerous pursuit. The dramatic descriptions of the long falls themselves from heights as high as 102,800 feet---made more brutal because the chute itself is of no use until a much lower altitude in reached---are of course the book's most vivid sections. Of especial interest to those interested in aviation, or to the larger audience hankering after true adventure.