Ulysses Ends Its Odyssey

After more than 18 years and almost three complete polar orbits around the sun, JPL's controllers of the Ulysses spacecraft have called it a mission. The joint NASA/ESA spacecraft was shut down on June 30 as it began to slowly succumb to the cold of deep space. (Ulysses' six-year orbit takes it out to Jupiter and back.) The doughty probe had exceeded its designed lifetime by nearly fourfold and covered almost two complete 11-year cycles of solar activity, providing grist for more than 1,000 scientific papers and two books so far.

Ulysses was the first mission to survey the north and south polar regions of the heliosphere, the "bubble created by the solar wind. Besides monitoring the solar wind and the local magnetic field, the spacecraft measured radio, X-ray, gamma-ray, and particle emissions from the sun, Jupiter, deep space, and even a couple of passing comets, flying through their tails. —DS