Explorer 1 is a long-running series of space missions developed by NASA, dating back to the launch of Explorer 1 on January 31, 1958, which was the first successful U.S. satellite. The mission marked the United States' entry into the Space Age, following the Soviet Union's launch of Sputnik 1. Explorer 1 played a crucial role in discovering the Van Allen radiation belts, regions of charged particles trapped by Earth’s magnetic field, significantly advancing scientific understanding of the space environment.
The Explorer program includes a wide range of satellites designed to study various aspects of space science, from Earth's atmosphere and magnetosphere to interplanetary and cosmic phenomena. Over the decades, more than 90 Explorer missions have been launched, contributing to discoveries in areas such as cosmic rays, space weather, solar physics, and astrophysics.
