Astronaut John Glenn tests balance mechanism performance
S64-14849 (1962) --- Astronaut John H. Glenn Jr.'s balance mechanism (semi-circular-canals) is tested by running cool water into his ear and measuring effect on eye motions (nystagmus). Photo credit: NASA
The Space Race began with a shock to the American public when the Soviet satellite Sputnik was launched in 1957. United states created NASA accelerate U.S. space exploration efforts and launched the Explorer 1 satellite in 1958. The Soviet Union was first again when it puts the first human, cosmonaut Yuri Gagarin, into a single orbit on April 12, 1961. Shortly after this, on May 5, the U.S. launched Alan Shepard, on a suborbital flight and reached its orbital goal on February 20, 1962, when John Glenn made three orbits around the Earth in the Mercury capsule. The Mercury space capsule was a pressurized cabin produced by McDonnell Aircraft and carried supplies of water, food, and oxygen for about one day. Mercury was launched on a top of modified Atlas D ballistic missiles. The capsule was fitted with a launch escape rocket to carry it safely away from the launch vehicle in case of a failure. Small retrorockets were used to bring the spacecraft out of its orbit, after which an ablative heat shield protected it from the heat of atmospheric reentry. Finally, a parachute slowed the craft for a water landing. Both astronaut and capsule were recovered by helicopters deployed from a U.S. Navy ship. The Mercury project missions were followed by millions on radio and TV around the world. Its success laid the groundwork for Project Gemini, which carried two astronauts in each capsule and perfected space docking maneuvers essential for manned lunar landings in the Apollo program announced just a few weeks after the first manned Mercury launch.