On Oct. 4, 1957, the Soviet Union put the world's first artificial satellite, Sputnik I, into Earth orbit and ushered in the modern space age. Sputnik (“traveling companion”) was spherical in shape with four antennas about 8 to 9 feet in length, 23 inches in diameter, and weighed 183.4 pounds. It circled the globe every 96 minutes at a speed of 18,000 miles per hour for 92 days until Jan. 4, 1958, when it re-entered the atmosphere and burned up.
Sputnik I orbited the Earth between 156 miles at its perigee (low point) and 560 miles at its apogee (high point). Its two radio transmitters marked the first time in history that man-made radio signals were sent from space to the Earth.
A month later on Nov. 3, 1957, the Soviet Union launched Sputnik II, the world's first satellite put into orbit with an animal housed aboard, an 11 lb. mongrel dog named Laika (“barker”). She died a week later after the oxygen supply ran out. The satellite carried more sophisticated instrumentation, weighed 1,120 lbs and circled the Earth every 103.7 minutes. Its orbit was approximately 145 miles at its perigee and 1,056 miles at its apogee. The satellite burned up after being in orbit for 162 days.
|Some Giant Telescopes||Space Exploration||First U.S. Satellite|