Sputnik 1 was launched by the Soviet Union and was the first human-made object to be launched into space, triggering the Space Race. Its main objectives were to successfully be launched into orbit around the earth, calculate the density of the atmosphere as well as testing propagation of radio waves. Signals came in from Sputnik for 21 days, until the transmitter battery ran out. On January 4th, 1958 Sputnik fell from orbit and burned up as it descended through the atmosphere.