March 17, 1958 (28) Reform Movement of the first month, the U.S. Navy successfully Vanguard-1 satellite was launched into Earth orbit.

1958 17, following the first satellite - Explorer 1 launched the second gold of the U.S. satellite Vanguard 1 (VANGUARD 1) successful launch. Pioneer No. 1 for a small Earth orbiting satellites, the housing is made of a 15.2 cm diameter aluminum alloy, weighs only 1.47 kg, and is used to test the the three rocket ship launch capability. This satellite design is expected to maintain nearly 1000 use lifespans, powered by solar cells in orbit, the continuous transfer of nearly three years of data back to Earth, and thus scientific satellites successfully proved the Earth the shape is not a perfect circle, and the shape of the pear. (Lsjt.net)