Explorer 1 and the Birth of the US Space Age

On January 31, 1958, the United States successfully launched Explorer 1, the nation’s first satellite, marking a pivotal moment in the early space age. Built here on Lab, and launched atop a Juno I rocket from Cape Canaveral, the primary science instrument on Explorer 1 was a cosmic ray detector designed to measure the radiation environment in Earth orbit. The mission soon delivered a historic discovery: evidence of the radiation belts surrounding Earth, later named the Van Allen belts.

At JPL, the achievement was celebrated almost immediately. Just days after launch, employees gathered in the cafeteria on Lab for a reprieve from their intense work schedule. Alongside the photo above, the February 1958 issue of Lab-Oratory, JPL’s internal newsletter, described the scene: “FREE COFFEE BREAK! The JPL satellite was the topic for the day… It was a rainy day, but it didn’t dampen any of our enthusiasm. Our satellite had been up since Friday night.” Scientists and engineers who had worked through the final push spoke in the cafeterias, sharing the story of the mission’s rapid development.

The newsletter noted that Director Pickering (pictured above on the left) thanked the entire workforce for their effort, emphasizing the remarkable timeline: JPL had placed a satellite in space in just 80 days.

Only months later, in October 1958, JPL was formally transferred to the newly created National Aeronautics and Space Administration (NASA). Explorer 1 demonstrated that ambitious exploration and rapid technological innovation were possible — setting the stage for the Laboratory’s continuing role in robotic space exploration and scientific discovery. CL#26-0870

The content presented here should be viewed in the context of the time period. Our intent is to present the history of JPL in a factual manner that uses primary resources and historical context. We recognize that some information or images do not reflect the current values, policies, and mission of JPL.