Faulty Control System Delays Shuttle Launch : Space: Judge denies environmentalists’ request to block flight because of nuclear-powered probe.

The planned Thursday launch of the space shuttle Atlantis was postponed Tuesday for several days because of a faulty control system in one of its three main engines.

The postponement occurred shortly after a federal judge in Washington cleared the way for the launching of the shuttle--which will carry the long-awaited Galileo mission to Jupiter--by denying the request of environmental activists for a temporary restraining order.

The activists had argued that the nuclear-powered Galileo probe posed a major health and safety risk should the shuttle explode on liftoff.

Launch director Bob Sieck said that it was decided to delay the launching after engineers had tested a master controller for several hours and could not learn why it had given a false signal during a check Monday night.

Sieck said that work on replacing the controller, which monitors engine performance during ascent, would start immediately and would take from five to seven days.

Robert Crippen, the astronaut who is chairman of the National Aeronautics and Space Administration committee that decides whether or not to launch the shuttle, said that the Atlantis could not blast off until engineers figured out why a sensor in the control system had failed the earlier test.

Crippen added that, if the controller failed during launching, “you could shut down an engine when you didn’t want to,” meaning the launching would be aborted.

The postponement overshadowed the court action, which had dominated discussion of the Atlantis mission for days.

“It is not the function of this court to decide whether the government’s decision to go forward with the Galileo mission is a good one,” U.S. District Judge Oliver Gasch wrote in his 17-page decision, released nearly seven hours after the conclusion of the hearing.

“It is my job to rule whether the environmental impact statement filed by NASA has enough information to allow the agency to take a hard look at the issues and make a reasoned decision,” Gasch wrote.

“Countdown has already begun,” he continued, “and the government states that the mission is ready for launch. The court concludes that NASA has complied with requirements of the National Environmental Protection Act.”

Lawyers for the plaintiffs--the Florida Coalition for Peace, the Christic Institute and the Washington-based Foundation on Economic Trends--said they would appeal the decision today.

The groups had asked for a temporary restraining order to block the launching long enough for them to seek a permanent injunction, arguing that NASA had underestimated the risks associated with the mission.

But Gasch sided with NASA space experts.

“An accidental plutonium release at various stages of the mission might cause an increase in cancer rates--although it is disputed whether (the) increase would be significant,” Gasch wrote. “NASA concludes that the residual risks associated with the Galileo mission are two to three times less than many of the risks associated with everyday life.”

Privately, some NASA officials were outraged over the lawsuit, which they maintain ignores the extensive testing carried out by NASA and the U.S. Department of Energy to ensure that even a catastrophic accident would not release a significant amount of plutonium into the atmosphere.

Publicly, however, the officials maintained that Galileo’s opponents have every right to challenge the launching in the courts.

“Citizens have a right to exercise their rights,” said Richard Spehalski of the Jet Propulsion Laboratory, Galileo project manager. “But, to me, it is an emotional reaction.”

Spehalski, who has been involved with the project since 1977, noted that there have been many problems during the 12-year life span of the much-delayed Galileo.

“It’s just one more rock in the road to Jupiter,” he said of the lawsuit.

“The fundamental issue in this case is whether the defendants adequately complied with environmental laws,” argued Edward Lee Rogers, counsel for the Florida Coalition for Peace and Justice. After citing government studies indicating that the statistical probability of a shuttle accident is 1 in 78, Rogers concluded: “If ever a case needs to comply fully to the letter of the law, this one is it.”

“This particular mission has been analyzed and reanalyzed more than any other mission,” Edward Frankle, general counsel for NASA, said after the hearing. “If we waited for people to come along who were infallible, we’d still be in caves.”

Andrew Kimbrell, counsel for the Foundation on Economic Trends, said that launching a nuclear-powered satellite in a manned space flight is a calculated risk not worth taking.

“If the Challenger explosion taught us anything, it should have taught us not to trust NASA’s risk assessment,” Kimbrell said. “They’re playing ecological roulette with the people of Florida.”

Before the postponement was announced, weather presented another threat to a Thursday launching.

Ed Priselac, the shuttle weather officer, said it has rained harder over the last two days than “any time since I’ve been here, and I’ve been here two years.”

“At my house, we got eight or 10 inches,” he said. “We had a ton.”

Under NASA rules, the shuttle may not be launched if there is a cloud over the spaceport that would expose the vehicle to any rain as it climbs through the atmosphere.

Lee Dye reported from the Kennedy Space Center and Kevin Davis from Washington.