Virgil Ivan "Gus" Grissom was an American engineer and pilot in the United States Air Force, as well as one of the original men, the Mercury Seven, selected by the National Aeronautics and Space Administration for Project Mercury, a program to train and launch astronauts into outer space. Grissom was also a Project Gemini and Apollo program astronaut for NASA. As a member of the NASA Astronaut Corps, Grissom was the second American to fly in space in 1961. He was also the second American to fly in space twice, preceded only by Joe Walker with his sub-orbital X-15 flights.

The Mercury Seven were the group of seven astronauts selected to fly spacecraft for Project Mercury. They are also referred to as the Original Seven and Astronaut Group 1. Their names were publicly announced by NASA on April 9, 1959: Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton. The Mercury Seven created a new profession in the United States, and established the image of the American astronaut for decades to come.