Explorer 1 was the first U.S. satellite and the first satellite to carry science instruments. The satellite was launched on Jan. 31, 1958, from Cape Canaveral, Fla.. Explorer 1 followed a looping flight path that orbited Earth once every 114 minutes. The satellite went as high as 2,565 kilometers (1,594 miles) and as low as 362 kilometers (225 miles) above Earth.
Explorer 1 stopped transmitting when its batteries ran out on May 23, 1958. It stayed in orbit for a dozen years, making a fiery reentry over the Pacific Ocean on March 31, 1970.
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