Ulysses (U.S. and European Space Agency)

Destination: The Sun. Launched: Oct. 6, 1990. Mission: To study the Sun and map the interstellar space above and below its poles. The spacecraft was put into orbit at right angles to the solar system's ecliptic plane. This special orbit enabled Ulysses to examine for the first time the Sun's north and south polar regions. Besides investigating the Sun, the spacecraft is also studying phenomena from the Milky Way and beyond. The spacecraft completed its first full orbit around the Sun on April 17, 1998, and continues to orbit the Sun. Ulysses made its closest approach to Jupiter in Feb. 2004.