When was Explorer 1 launched?
Explorer 1 launched on the 1st of February 1958 at 03:47:56 GMT from Launch Complex 26A at Cape Canaveral, Florida. A jet stream had forced a delay from the original the 28th of January 1958 attempt.
Questions about Explorer 1
Short answers, pulled from the story.
What did Explorer 1 discover in orbit?
Explorer 1 was the first spacecraft to detect the Van Allen radiation belt, a band of charged particles trapped by Earth's magnetic field. The discovery was confirmed by the follow-up Explorer 3 mission, which carried a tape data recorder, and was counted among the outstanding discoveries of the International Geophysical Year.
Who built Explorer 1?
Explorer 1 was designed and built by the Jet Propulsion Laboratory under Dr. William Hayward Pickering of the California Institute of Technology. The Army Ballistic Missile Agency modified the Jupiter-C into the Juno I launch vehicle. The two organizations completed the work in 84 days.
How long did Explorer 1 remain in orbit?
Explorer 1 remained in orbit for more than 12 years after its launch on the 1st of February 1958. It reentered the atmosphere over the Pacific Ocean on the 31st of March 1970 after completing more than 58,400 orbits.
Why did Explorer 1 show zero cosmic ray readings?
Explorer 1's Geiger counter was saturated by intense radiation from the Van Allen radiation belt, a zone of charged particles trapped by Earth's magnetic field. The zero readings appeared consistently on passes above 2,000 kilometers over South America. Explorer 3, which carried a tape data recorder, later confirmed this explanation.
How did the weight of Explorer 1 compare to Sputnik 1?
Explorer 1 had a total mass of 13.97 kilograms, of which 8.3 kilograms were scientific instruments. Sputnik 1, the first Soviet satellite, weighed 83.6 kilograms.