Colonel John Herschel Glenn Jr. (July 18, 1921 – December 8, 2016) was a United States Marine Corps aviator, engineer, astronaut, and United States Senator from Ohio. In 1962, he became the first American to orbit the Earth, circling it three times.
Before joining NASA, Glenn was a distinguished fighter pilot in World War II, China and Korea. He shot down three MiG-15 aircraft, and was awarded six Distinguished Flying Crosses and eighteen Air Medals. In 1957, he made the first supersonic transcontinental flight across the United States. His on-board camera took the first continuous, panoramic photograph of the United States.
He was one of the Mercury Seven, military test pilots selected in 1959 by NASA as the United States' first astronauts. On February 20, 1962, Glenn flew the Friendship 7 mission, becoming the first American to orbit the Earth, and the fifth person and third American in space. He received the NASA Distinguished Service Medal in 1962 and the Congressional Space Medal of Honor in 1978, was inducted into the U.S. Astronaut Hall of Fame in 1990, and was the last surviving member of the Mercury Seven.
Glenn resigned from NASA in January 1964. He planned to run for a U.S. Senate seat from Ohio, but an injury in February 1964 forced his withdrawal. He retired from the Marine Corps the following year. He lost a close primary election in 1970. A member of the Democratic Party, Glenn first won election to the Senate in 1974 and served for 24 years until January 1999. In 1998, while still a sitting Senator, Glenn became the oldest person to fly in space as a crew member of the Discovery space shuttle and the only person to fly in both the Mercury and Space Shuttle programs. He received the Presidential Medal of Freedom in 2012.