The first man-made satellite launched into space was Sputnik 1. Launched by the Soviet Union on October 4, 1957, Sputnik 1 marked the beginning of the space age and the space race between the United States and the Soviet Union. The satellite was a 58-centimeter metal sphere equipped with four external radio antennas, which transmitted radio pulses that could be received on Earth. Sputnik 1's successful launch had a profound impact on technology, politics, and exploration, inspiring advancements in satellite technology and igniting interest in space exploration among nations worldwide.