July 21 – Mercury program: Gus Grissom, piloting the Mercury-Redstone 4 capsule Liberty Bell 7, becomes the second American to go into space (sub-orbital). Upon splashdown, the hatch prematurely opens, and the capsule sinks (it is recovered in 1999).
Mercury Spacecraft, designed and built by McDonnell, St. Louis for NASA. Signed by the six astronauts who flew in the Mercury program: Alan B Shepard, Gus Grissom, J H Glenn, Jr., Scott Carpenter, Wally Schirra and Gordon Cooper.
Virgil Ivan Grissom (April 3, 1926 – January 27, 1967), (Lt Col, USAF), better known as Gus Grissom, was one of the original NASA Project Mercury astronauts and a United States Air Force pilot. He was the second American to fly in space, and the first member of the NASA Astronaut Corps to fly in space twice. Grissom was killed along with fellow astronauts Ed White and Roger Chaffee during a pre-launch test for the Apollo 1 mission at Cape Canaveral Air Force Station.