In this historical photo from the U.S. space agency, the three men responsible for the success of Explorer 1, America's first Earth satellite which was launched January 31, 1958.
At left is Dr. William H. Pickering, former director of JPL, which built and operated the satellite. Dr. James A. van Allen, center, of the State University of Iowa, designed and built the instrument on Explorer that discovered the radiation belts which circle the Earth. At right is Dr. Wernher von Braun, leader of the Army's Redstone Arsenal team which built the first stage Redstone rocket that launched Explorer 1.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).