X-15 Diary

Built of titanium and a chrome-nickel alloy known as Inconel X, the X-15 was the fastest plane ever built, streaking through the lower reaches of outer space even before the first space capsules reached orbit. First tested in 1959, the X-15 proved to be a crucial testing ground for the astronauts and hardware in the Mercury, Gemini, Apollo, and even the Space Shuttle programs. Celebrated reporter ...