Galileo Probe Near Jupiter Moon
LOS ANGELES (AP) _ NASA’s aging Galileo spacecraft flew within 380 miles of Jupiter’s moon Io, exposing the craft to so much radiation that mission controllers feared the probe might not survive.
No problems were reported, however, after the closest-ever flyby of Jupiter’s innermost large moon took place Sunday at 10:06 p.m. PDT, said project manager Jim Erickson of NASA’s Jet Propulsion Laboratory in Pasadena.
``Everything is looking pretty good,″ he said. ``None of the normal things that would have indicated problems have shown up.″
Io’s orbit lies in an area of intense radiation from Jupiter’s radiation belts. Galileo, which was launched in 1989 and arrived at Jupiter on Dec. 7, 1995, has in recent months experienced problems with its stabilizing gyros and computers as years of radiation from the solar system’s largest planet have taken their toll.
Radio signals streaming back from Galileo did not show any signs of major trouble, though. Engineers designed software to help the probe figure out big problems from minor glitches and respond appropriately.
The probe was to continue sending basic telemetry until 3 p.m. today. Science readings and photographs will be sent through Thanksgiving.
Galileo’s instruments are studying the chemistry, heat distribution, gravity and magnetic properties of Io, the only known volcanic solar system object other than Earth.
``It gives us the opportunity to do comparisons between a non-Earth volcanic system and the Earth,″ Erickson said. ``We learn something about both of them in the process.″
Galileo is scheduled to make an even closer approach of Io on Nov. 25, flying within 186 miles of the surface. The spacecraft completed its $1.5 billion primary mission in 1997 and will finish a $30 million, two-year extended mission in January.