Pioneer 10

Pioneer 10 (originally designated Pioneer F) is a NASAspace probe launched in 1972 that completed the first mission to the planet Jupiter. It was the first spacecraft to traverse the asteroid belt and the first of five artificial objects to achieve the escape velocity needed to leave the Solar System. The mission was managed by NASA Ames Research Center in California, and the spacecraft was built by TRW Inc.

The spacecraft was built around a hexagonal satellite bus with a 2.74 m (9.0 ft) diameter parabolic high-gain antenna and was spin-stabilized about the antenna axis. Electrical power was supplied by four radioisotope thermoelectric generators (RTGs), which produced a combined 155 watts at launch.

Pioneer 10 was launched on March 3, 1972, at 01:49:00 UTC (March 2 local time), aboard an Atlas-Centaur rocket from Cape Canaveral Launch Complex 36A. It passed through the asteroid belt from 15 July 1972 to 15 February 1973, becoming the first spacecraft to do so. Imaging of Jupiter began on November 6, 1973, from a distance of 25 million km (16 million mi), and the spacecraft returned more than 500 images. Its closest approach to Jupiter was on December 3, 1973, passing within 132,252 km (82,178 mi) of the planet. During the mission, its scientific instruments investigated the asteroid belt, the environment of Jupiter, the solar wind, cosmic rays, and the outer heliosphere.

The last signal from Pioneer 10 was received on January 23, 2003, after declining electrical power from its RTGs left the spacecraft unable to operate its radio transmitter. At that time, it was about 80 AU (12 billion km; 7.4 billion mi) from Earth.