The primary mission of the Ulysses spacecraft was to characterize the heliosphere as a function of solar latitude. The heliosphere is the vast region of interplanetary space occupied by the Sun's atmosphere and dominated by the outflow of the solar wind. The periods of primary scientific interest is when Ulysses was at or higher than 70 degrees latitude at both the Sun's south and north poles. On 26 June 1994, Ulysses reached 70 degrees south. There it began a four-month observation from high latitudes of the complex forces at work in the Sun's outer atmosphere-the corona.

Scientists have long studied the Sun from Earth using Earth-based sensors. More recently, solar studies have been conducted from spaceborne platforms; however, these investigations have been mostly from the ecliptic plane (the plane in which most of the planets travel around the Sun) and no previous spacecraft have reached solar latitudes higher than 32 degrees. Now that Ulysses high latitude data is available, scientists from the joint NASA and ESA mission are obtaining new and better understanding of the processes going on at high solar latitudes.