Science panel supports eventual suicide for Galileo spacecraft

PASADENA, Calif. - A tentative plan to send NASA's Galileo spacecraft on a suicide plunge into Jupiter's atmosphere to avoid any chance of contaminating the planet's potentially life-harboring moons has gained the support of a panel of independent scientists.

The Committee on Planetary and Lunar Exploration, which is part of the National Academy of Sciences' Space Studies Board, also agreed Friday with the agency's plan to get as much work as possible out of the probe before its navigation systems fail.

Galileo has been orbiting the solar system's largest planet since 1995 but is running low on fuel. The spacecraft's electronics have encountered three times as much radiation from the Jupiter system as they were designed to withstand.

While simply leaving the spacecraft adrift has not been ruled out, mission officials fear that if they do that, the craft might someday crash into the moon Europa, which is suspected of having a liquid ocean under its icy crust. Any Earth organisms still alive on the craft could conceivably contaminate the moon.

However, the committee concluded that Galileo can survive additional flybys of the moons, which are deep within Jupiter's radiation belts. They said the spacecraft's backup system continue to function well.

No date has been set for the mission's end, but Claude Canizares, chairman of the Space Studies Board, said: ''We're not talking about leaving it up there for 10 years.''

Galileo is funded through the end of the year, when it will be making joint observations of Jupiter with the Cassini spacecraft, which is headed toward Saturn.

The committee's report has been forwarded to John Rummel, NASA's planetary protection officer, who will make a recommendation to NASA headquarters. He was on vacation Friday and unavailable for comment.

Galileo, launched in 1989, completed its primary exploration of the Jupiter system in 1997. It is now on its second extended mission and remains in good shape as mission controllers prepare for its joint observations in December with the Cassini probe.

''We're pretty healthy and pretty happy,'' said Jim Erickson, Galileo's project manager at the agency's Jet Propulsion Laboratory in Pasadena. ''And we're ready to figure out what to do next.''

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On the Net: The National Academies: http://www.nationalacademies.org/

Galileo home page: http://galileo.jpl.nasa.gov