After the Soviet cosmonaut Yuri Gagarin became the first man in space in 1961, the United States felt pressured to push ahead with its Mercury program, which flew six manned missions from 1961 to 1963.
The Mercury missions would answer questions about man's ability to function in space. Astronaut Alan B. Shepard, Jr., who flew the first capsule on May 5, 1961, proved that a person could control a spacecraft even in weightlessness. The crafts that he and the other six Mercury astronauts piloted were bell-shaped capsules designed for one person. The cabin looked just like the cockpit of a fighter plane.
On their return to Earth, Mercury capsules were landed in the ocean, where naval vessels and helicopters recovered them. All but one capsule, Mercury 4, were successfully recovered. On splashdown, Mercury 4 's hatch blew open, and the capsule filled with water. Astronaut Virgil I. "Gus" Grissom was barely rescued from drowning as the craft sank.
