By the 1950s, scientists all over the world realized that it was becoming practical to launch an object into a circular path around the Earth. In mid-1955, the United States announced that it would launch the first satellite to commemorate the International Geophysical Year in 1957. The Soviet Union realized that 1957 was the 40th anniversary of the Bolshevik Revolution.
Starting in early 1956, Soviet scientists had worked to design a large satellite with a mass of up to 3,000 pounds (1,400 kg). Codenamed “Object-D,” the craft would have become the world’s first space satellite, taking measurements of the upper atmosphere and the space environment. The complex Object D took longer to develop than expected.
To avoid being upstaged by the Americans, the smaller Sputnik 1 was launched first. Object-D ultimately flew as Sputnik 3 in 1958. Sputnik was in the form of a sphere, 23 inches (58 centimeters) in diameter and pressurized with nitrogen. Four radio antennas trailed behind. Two radio transmitters within the sphere broadcast a distinctive beep-beep sound that was picked up all over the world. Silver-zinc batteries powered the transmitter for 22 days before giving out.
After about three months, Sputnik fell into the Earth’s atmosphere and burned up. Sputnik’s official designation was “PS-1” or “Elementary Satellite 1” in Russian. The satellite was launched from what is now called the Baikonur Cosmodrome on Oct. 4, 1957. The 184.3-pound (83.6 kg) craft’s primary function was to place a radio transmitter into orbit around the Earth.