By Hillary F. and Khoi N.
Explorer 1 was the first satellite launched by the United States when it was sent into space on January 31, 1958.The satellite landed safely on March 13, 1970. Its main purpose was to orbit earth and study it. People that were associated with the mission were Al Hibbs and Dr. Wernher von Braun. The mission was unmanned because the Americans didn't want to risk lives since it was there first mission. The material involved with the mission were a cosmic ray detector, a micrometeorite detector, a satellite drag an atmospheric density and a temperature sensor. Explorer 1 orbited Earth every 115 minutes, 358 kilometers. Explorer 1 discovered a radiation belt inside of Earth.