Galileo

A NASA spacecraft for the exploration of Jupiter, its rings and satellites. It was launched in October 1989 from the Space Shuttle and arrived at Jupiter in December 1995. The flight plan included flybys of the asteroids Gaspra and Ida en route. When Galileo was launched, more than twenty years had elapsed since the mission was first conceived. Initially, the launch had been planned for 1983. Following various problems, including the loss of the Challenger Space Shuttle, it was impossible to obtain sufficient power by means of the Shuttle launch for a direct journey to Jupiter. Engineers therefore designed a gravity-assisted flight plan, whereby the craft was accelerated by close passages by Venus and twice by the Earth during the first three years. A major disappointment was the failure of the craft's high-gain communications antenna. Having only a low-gain antenna working limited the amount of data that could be transmitted back to Earth. However, Galileo otherwise worked well, despite some problems with its tape recorders. It entered orbit in the jovian system, returning high-resolution images of the Galilean moons. A probe carried by Galileo separated from the craft and entered Jupiter's atmosphere on 7 December 1995. It parachuted down, returning data on the composition and physical state of the atmosphere for 57 minutes.