Ulysses

Mission Profile

Ulysses was a joint ESA/NASA spacecraft designed to study the Sun's polar regions and the heliosphere at high solar latitudes, launched on 6 October 1990 from Space Shuttle Discovery and directed to Jupiter for a gravity assist that swung it into a polar solar orbit. Orbiting the Sun with inclinations up to 80° out of the ecliptic, Ulysses made three complete orbits measuring the solar wind, magnetic field, cosmic rays, and dust environment over both solar poles at solar minimum and maximum conditions. The mission revealed that the solar wind speed and structure differ markedly between equatorial and polar regions, and that the high-latitude heliosphere contains a surprisingly uniform magnetic polarity. Ulysses operated for 18.5 years until fuel depletion in 2009, far outlasting its planned 5-year mission.