On this day in 1998, John Glenn returned to space and became the oldest human to do so.

John Glenn was the first American to orbit the Earth, preforming a four-hour flight in the Friendship-7 spacecraft on Feb. 20, 1962. After retiring from the Astronaut Corps. and serving as a U.S. Senator, Glenn was chosen to fly aboard the shuttle Discovery for STS-95.

Glenn participated in several medical experiments that made use of his unique status, and still holds the record for the longest duration between two spaceflights.

Learn more about John Glenn’s return to space here.