/
Launch Success
Liftoff Time (GMT)
17:38:03
Wednesday March 26, 1958
Watch Replay
Official Livestream
Explorer 3 was launched in conjunction with the International Geophysical Year (IGY) by the U.S. Army (Ordnance) into an eccentric orbit. The objective of this spacecraft was a continuation of experiments started with Explorer 1. The payload consisted of a cosmic ray counter (a Geiger-Müller tube), and a micrometeorite detector (a wire grid array and acoustic detector). The Explorer 3 spacecraft was spin-stabilized and had an onboard tape recorder to provide a complete radiation history for each orbit.
Medium Earth Orbit
1 Payload
14 kilograms
3rd
Mission
3rd
Mission of 1958
5th
Orbital launch attempt