Cassini launch rescheduled for this morning

Several scientists from the University of Arizona's Lunar and Planetary Laboratory play key roles in the mission, and planned to watch the launch scheduled for 4:33 a.m. EST.

"We're confident that it's going to go," said Robert H. Brown, team leader for the Visual and Infrared Mapping Spectrometer instrument aboard Cassini.

"The numbers I've heard are about 80 percent that it will launch in the morning," he added.

NASA postponed launch Monday because of 90 mph high-altitude winds and a possible glitch in a on-board computer program.

"The upper-level winds were such that if the worst happened and they had to press the button to destroy the rocket, they were afraid that the winds might carry plutonium back into populated areas," Brown said.

Cassini's instruments will be powered by electricity generated from 72 pounds of plutonium aboard the craft. The possibility of an accident that could leave radioactive material in the atmosphere has made the mission controversial.

As of 8 p.m. yesterday, weather at the launch site had improved for launch.

A frontal system moving into Florida had reversed the upper level winds and brought them to a stop by yesterday afternoon, Brown said, and the forecast was favorable for the winds to remain low until launch time this morning.

The technical computer problem had also been solved, he said.

UA scientist Martin Tomasko said he was also eager for launch, but would not be upset if it were delayed again.

"The launch window extends until Nov. 4, so there is plenty of time if the weather doesn't cooperate," Tomasko said. "I'm glad they're being cautious and slow. We don't need people panicking," he said.

Tomasko is principal investigator for the Descent Imager and Spectral Radiometer, a camera that is mounted on board a probe that will descend through the atmosphere of Saturn's largest moon, Titan.

"We're all going to get some sleep and get up about 3:30 (EST) and caravan to a viewing area about 10 miles away from the launch site, which is the closet location to view the launch with a large group of people," Brown said.

"There is a press area that is somewhat closer, but I elected to watch the launch with the rest of the VIMS team where we could all be together and have a good time," Brown said.

The VIMS science team includes eight Americans and 13 Europeans, most of whom have brought friends and family to watch the launch.

UA Lunar and Planetary Laboratory scientist Carolyn Porco, leader of the imaging team for the Cassini orbiter called the launch "a momentous occasion."

"We just want to see everything go off well," Porco said.

"I'll be stupendously excited, I've never seen a launch like this before. I've been told it will be as bright as daylight for a few seconds," she said.

"After seven years it will be good to see this thing go," Brown said.