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[STOCK] Explorer 1

Launched on January 31, 1958, Explorer 1 was the first satellite of the United States, marking America’s entry into the Space Race. Built by the Jet Propulsion Laboratory (JPL) and launched aboard a Juno I rocket from Cape Canaveral, the satellite was a small cylindrical spacecraft measuring 2.03 m (6 ft 8 in) long and weighing about 14 kg (30.8 lbs).

Explorer 1 carried scientific instruments including a cosmic ray detector designed by Dr. James Van Allen. Data returned from the mission led to the discovery of the Van Allen radiation belts, a major milestone in space science.

The satellite orbited Earth in a highly elliptical orbit, ranging from about 358 km (222 mi) at perigee to 2,550 km (1,585 mi) at apogee, completing one orbit every 114.8 minutes. It transmitted data for nearly four months before its batteries were exhausted, but remained in orbit until 1970, when it reentered Earth’s atmosphere and burned up.

AG1 to extend antennas