Countdown Resumes for Cassini Mission to Saturn

The countdown resumed Tuesday for a launch early today of NASA’s controversial nuclear-powered Cassini probe to Saturn after engineers fixed a technical problem at the launching pad.

Cassini’s U.S. Air Force Titan 4B rocket was supposed to have left Monday but was delayed by a problem with a battery testing device on the launching pad, minor computer glitches and high upper-level winds that posed a safety threat in the event of an explosion during launching.

Air Force meteorologists forecast an 80% chance of fair weather for liftoff at 1:43 a.m. PDT.

Cassini’s plutonium power source has generated controversy over whether the mission should be considered a threat to Florida residents.

National Aeronautics and Space Administration officials say the chance of an accident causing the release of the radioactive plutonium is 1 in 1,400. Antinuclear activists, who contend that any risk is too high, say the space agency has its figures wrong.

The probe has until Nov. 4 to embark on its 2.2-billion-mile trip. A launching after then would expend more of its valuable maneuvering fuel, extend its journey by up to two years and reduce its science-gathering capability on Saturn.

Cassini was scheduled to spend four years touring Saturn’s rings and moons and drop a probe onto its largest moon, Titan.