Explorer 1 was the first satellite launched by the United States when it was sent into space on January 31, 1958.
The Jet Propulsion Laboratory & Dr. James A. & Dr. Wernher all was apart of the Creation of the Satellite. The satellite discovered radiation belts which circle the Earth. This was important for the United States to have an successful satellite because the Soviet Union was the first to do it before us.
Explorer 1 made its final transmission on May 23, 1958. It entered Earth's atmosphere and burned up on March 31, 1970, after more than 58,000 orbits. This is still today a big reason why the U.S learned how to keep our satellite up in space for awhile and get more information.