Goals: Giotto was designed to photograph and study comet Halley 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 605 km (376 miles) 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 -- 200 km (124 miles) -- by comet Grigg-Skjellerup in 1992. That flyby revealed even more information about comets. Giotto was also the first deep space misison to change its orbit by returning to Earth for a gravity assist.