NASA is celebrating the 50th anniversary of the first American in orbit.
Back in 1959, NASA selected John Glenn as one of the original group of seven astronauts for the Mercury program.
Three years later, he blasted off to the famous words, "Godspeed John Glenn," becoming the first American to orbit the Earth. To honor this landmark, we’re taking a look back at Glenn’s historic flights into space.
First American to circle the Earth
On February 20, 1962, Glenn made his famous journey around the planet aboard NASA's Friendship 7 spacecraft. During the nearly five-hour mission, he circled the globe three times. The mission wasn't perfect. A trouble indicator light warned that a clamp holding the spacecraft's heat shield had been released too early. Mission controllers feared that the heat shield was loose. The shield was meant to protect Glenn's spacecraft from burning up during re-entry. As a safety measure, a "retropack" that would normally have been jettisoned was allowed to stay on the spacecraft to hold the heat shield. It turned out that warning light was a false alarm. Glenn splashed down safely to much fanfare at home. Watch the incredible archival footage of this historic trip.
Glenn made headlines again in 1998 when he rejoined NASA at age 77 to become the oldest person ever to go into space. Glenn’s trip aboard the shuttle Discovery helped NASA learn about the effects of space flight on older people. Watch him quip about breaking a hip in space.
Friday, at age 90, Glenn joined fellow “Mercury Seven” astronaut Scott Carpenter to reminisce about their adventures and reflect on the U.S. space program. Appropriately, it was Carpenter who announced those famous words a half century ago: "Godspeed John Glenn." Learn just how dangerous their missions were and what types of concerns that scientists had about Glenn’s health.
Follow us on Twitter @CNNLightYears