Ulysses in the Underworld

Getting a spacecraft much out of the plane of the ecliptic, where all the planets reside, is hard to do with rocket power alone. However, by using the gravitational pull of Jupiter as a sling, the Ulysses craft, launched in 1990, leveraged itself into a nearly circumpolar orbit over and under the sun. As of now Ulysses finds itself beneath the sun's southern pole for the third time, and will continue to make a variety of radiation and particle measurements.

See the official Ulysses Web site