Which astronaut was the first person to fly in space twice?

Gus Grissom was the first person to fly in space twice.

His first spaceflight was Mercury-Redstone 4, also called Liberty Bell 7, on 21 July 1961. In 1965, he commanded Gemini 3 with John Young, making him the first human to travel into space twice.

Gemini 3 was the first crewed flight of NASA’s Gemini program. The mission tested the two-person spacecraft, performed orbital maneuvers, and demonstrated the ability to control a spacecraft’s path in orbit. It lasted just under five hours.

Grissom is sometimes confused with John Glenn because Glenn was the first American to orbit Earth and later became the first American to fly in space twice after his 1998 Space Shuttle mission. Grissom’s second flight came much earlier, during the Space Race, and made him the first two-time space traveler.