Galileo probe returns to health

February 15, 1999

PASADENA, California (AP) -- The Galileo spacecraft is operating normally again, nearly two weeks after it went into semi-shutdown when its onboard computer became confused after a pass by Jupiter's moon Europa, officials said Friday.

The craft went back into normal mode on Wednesday after technicians sent it a series of commands.

Galileo went into "safing mode" on January 31, four hours after zooming by Europa to try to determine if it has ice-spewing volcanoes, said David Senske, a member of the Galileo imaging team at NASA's Jet Propulsion Laboratory.

After the approach, Galileo was turning to locate the sun so it could better position its antenna and beam data back to Earth, Senske said.

However, a "blind spot" between two sun sensors confused the onboard computer, which automatically shut down nonessential activities, including some instruments, switched to some backup hardware and sent out a signal to let technicians know it was going into the safing mode, Senske said.

The problem apparently was caused by the unusual angle Galileo had adopted in order to study Europa, Senske said.

Galileo was launched in 1989 and arrived at Jupiter on Dec. 7, 1995. It completed its $1.5 billion primary mission and is halfway through a $30 million extended mission focusing on Europa and other moons.

Copyright 1999 The Associated Press. All rights reserved.