Goals: Giotto was designed to photograph and study Halley's comet by passing as close as possible to its nucleus. It was equipped with two shields to absorb dust impacts, although it was not expected to survive the encounter.
Accomplishments: Europe's first deep space mission was a resounding success. Giotto survived an intense battering as it closed to a then-record of 376 miles (605 kilometers) from the comet's core and sent back about 2,000 images. The damaged spacecraft was then sent on to make an even closer pass—about 120 miles (200 kilometers)—by comet Grigg-Skjellerup in 1992. That flyby revealed even more information about comets. Giotto was also the first deep space mission to change its orbit by returning to Earth for a gravity assist.