John Herschel Glenn, Jr. (July 18, 1921 – December 8, 2016), (Col, USMC, Ret.), was a former U.S. Marine Corps aviator, engineer, astronaut and United States senator.
He was selected as one of the “Mercury Seven” group of military test pilots selected in 1959 by NASA to become America’s first astronauts and fly the Project Mercury spacecraft.
On February 20, 1962, Glenn flew the Friendship 7 mission and became the first American to orbit the Earth and the fifth person in space, after cosmonauts Yuri Gagarin and Gherman Titov and the sub-orbital flights of Mercury astronauts Alan Shepard and Gus Grissom. Glenn is the earliest-born American to go to orbit, and the second earliest-born man overall after Soviet cosmonaut Georgy Beregovoy, who was born three months and three days earlier. Glenn received the Congressional Space Medal of Honor in 1978, and was inducted into the U.S. Astronaut Hall of Fame in 1990. With the death of Scott Carpenter on October 10, 2013, Glenn became the last surviving member of the Mercury Seven.
Glenn resigned from NASA on January 16, 1964, and the next day announced plans to run for a U.S. Senate seat from Ohio. But injury from a bathtub concussion caused him to withdraw from the race the following March. He retired from the Marine Corps on January 1, 1965. A member of the Democratic Party, he finally won election to the Senate in 1974 and served through January 3, 1999. With the death of Edward Brooke on January 3, 2015, Glenn became the oldest living former United States Senator.
On October 29, 1998, while still a sitting senator, he became the oldest person to fly in space, and the only one to fly in both the Mercury and Space Shuttle programs, when at age 77, he flew as a Payload Specialist on Discovery mission (STS-95). He was awarded the Presidential Medal of Freedom in 2012.