John Glenn
Glenn resigned from NASA in January 1964. A member of the Democratic Party, Glenn was first elected to the Senate in 1974 and served for 24 years, until January 1999. Aged 77, Glenn flew on Space Shuttle Discovery's STS-95 mission, making him the oldest person to enter Earth orbit, and the only person to fly in both the Mercury and the Space Shuttle programs. Glenn, both the oldest and the last surviving member of the Mercury Seven, died at the age of 95 on December 8, 2016.