Ulysses launched in October 1990, is exploring the polar regions of the sun. Unlike most spacecraft, Ulysses does not orbit in the ecliptic plane, but across it. It uses Jupiter's strong gravitational field to give it a push out of the ecliptic plane and into its polar orbit around the sun.
The Space Sciences Laboratory's involvement in this spacecraft consists of two instruments: HISCALE (a high energy particle detector), and a gamma-ray and Xray detector.