(CBS Newspath) -- On this day in history, January 31, 1958 the United States entered the space age by launching its first satellite into Earth's orbit.
Explorer I was launched into orbit by a Jupiter-C Rocket that lifted off from Cape Canaveral, Florida. The satellite weighed just over thirty pounds and circled the earth every 114 minutes at a maximum altitude of 2000 miles and a minimum altitude of 230 miles. Explorer I was expected to have a life of 10 years.
Scientists in California picked up radio signals from explorer only minutes after its launch. The satellite was equipped to measure cosmic radiation found in space and sends its data back to earth. The major discovery of Explorer I was the innermost of two charged bands that surround the Earth called the Van Allen radiation belts.