On February 20, 1962, John Glenn, a 40-year-old Marine Corps colonel, became the first American to launch into orbit, finally evening up the score in a heated space race with the Soviet Union. Here's a look at Glenn's flight:
* After two launch cancellations, the Atlas rocket carrying John Glenn's Friendship 7 Mercury capsule blasted off from Cape Canaveral, Florida, at 9:47 a.m. EST.
* Glenn made three orbits of Earth before splashing down in the Atlantic Ocean southeast of Bermuda.
* Two major problems occurred during the flight, including a signal, later proved to be false, that a clamp holding Friendship 7's heat shield had been prematurely released. The shield is what kept the capsule from burning up when it plunged through the atmosphere during the return to Earth.
* Glenn carried phonetic translations of some key words (such as "friend") in primitive languages in case his capsule came down in a part of the world inhabited by aborigines.
* Glenn's 4-hour, 55-minute flight followed 15-minute suborbital flights by Alan Shepard and Gus Grissom in May and July 1961.
* Glenn left NASA in 1964 because he was not being given another flight. He later learned it was President John F. Kennedy himself who'd grounded him. "There was so much national attention, I suppose it would have been bad if something had happened on a second flight," Glenn said.
* Glenn finally got a second flight in 1998, as a member of a space shuttle crew. Then 77, he was a research subject for National Institutes of Health-sponsored experiments on aging.
* Glenn spent 25 years as a Democratic senator from Ohio and ran for U.S. president in 1984. He left the Senate in 1999.
* Glenn and Scott Carpenter are the only two of the original Mercury Seven astronauts who are still alive.