How much did Explorer 1 weigh?
The launch of Explorer 1 in January 1958 was the United States’ response to the Soviet Union’s launch of Sputnik I and II the previous fall.
The U.S. Army’s rocket team sent the craft into space, using technology that was developed in World War II. Wernher von Braun headed up the rocket group. Explorer 1 was responsible for finding what would come to be called the Van Allen radiation belts. Source: NASA
Explorer 1 was the first satellite of the United States, launched as part of its participation in the International Geophysical Year. The mission followed the first two satellites the previous year; the Soviet Union’s Sputnik 1 and 2, beginning the Cold War Space Race between the two nations.
The satellite went as high as 2,565 kilometers (1,594 miles) and as low as 362 kilometers (225 miles) above Earth. Explorer 1 was the first satellite launched by the United States when it was sent into space on January 31, 1958.