... John Glenn: Discovery Launch . ... At left, the Space Shuttle Discovery waits in darkness on Kennedy Space Center's launch pad 39B. At right, on Thursday October 29, Discovery blasts through a bright afternoon sky returning Senator John Glenn to space over 36 years after he became the first American in orbit. ... Rehearsing for his historic flight on February 20, 1962, Mercury program astronaut John H. Glenn Jr. works in a cramped training capsule preparing for a few hours' voyage through space. ...