Eleven years after the probe's launch, NASA is considering a spectacular finish for the space satellite Galileo: A suicide plunge into planet Jupiter or one of its moons.
Recently, navigators have been beaming increasingly risky orders to the probe to maximize the science in what are likely to be Galileo's final months.
The $1.4 billion probe is on its second extended mission since completing its primary goals in 1997. Fuel for maneuvering is running low, navigation equipment is failing and Galileo has encountered twice as much radiation as it was designed to withstand.
``This is all gravy at this point,'' said Jim Erickson, Galileo's project manager at the National Aeronautics and Space Administration's Jet Propulsion Laboratory. ``We've done the job. Now we're getting to see how much more we can milk it.''
If NASA orders Galileo to take the big plunge into the red planet, it will be a short flight.
The probe would send back only a few minutes of valuable data before frying from radiation, melting under the pressure of Jupiter's atmosphere or crashing onto a moon, scientists say.
The alternatives are to let the aging spacecraft run out of propellant or wait for a critical navigation component to fail. Either would turn it into a worthless piece of Jovian space junk.
However, NASA may not get a chance to order that final plunge.
On Tuesday, the 2.5-ton Galileo orbiter will fly within 124 miles of Jupiter's moon Io, in a maneuver that will bombard the probe with immense radiation. Engineers concede the pass could permanently knock the satellite out.
Galileo is then tentatively scheduled to zoom by the moon Ganymede in May and December.
If it survives all that, the spacecraft could be given its final marching orders sometime next year, although details are still being worked out.
Plunging into Jupiter could shed new light on the planet's magnetic fields. It also could be sent into one of Jupiter's moons, perhaps Io.
Galileo won't be flying into Europa, where last month its instruments discovered the best evidence yet of a liquid ocean beyond Earth, a hint of possible life on the planet. Galileo could still be carrying living microbes from earth that might contaminate life on Jupiter.
The discovery on Europa is one of a list of Galileo's accomplishments.
In October, Galileo flew within 380 miles of Io, revealing what may be the most active body in the solar system. The spacecraft found more than 100 volcanoes, some of which spewed 2,700-degree lava and vented gases miles into space.
Later, Galileo's camera captured lava spurting more than a mile high.
Galileo also found, for the first time, that Jupiter has Earth-style thunderstorms in addition to the monstrous, swirling storms that Earth astronomers have seen through telescopes for centuries.
Launched in 1989, Galileo traveled 2.3 billiomiles before reaching Jupiter in 1995.
The spacecraft is named after the Italian astronomer who first observed Jupiter's largest moons in 1610.