Goals: The main objective was to take UV images of Comet Halley's hydrogen coma for about 30 days before and after the comet's crossing of the ecliptic plane. The spacecraft was also to gather data on the solar wind.
Accomplishments: Suisei flew by Comet Halley at a distance of about 151,000 km, returning ultraviolet images from within the giant coma of hydrogen gas surrounding the nucleus. It detected cometary water, carbon monoxide and carbon dioxide ions, and observed at least two major and four minor outbursts. Suisei observed that the solar wind slowed from 350 km/s to 70 km/s at a distance of about 420,000 km from the comet.