NASA's long-delayed shuttle launch of the Galileo mission to Jupiter, already several years behind schedule because of the Challenger disaster, now faces a legal battle that could jeopardize next month's scheduled launch.
A Washington-based public interest law firm, the Christic Institute, and several other organizations plan to file suit today in Washington in an effort to block the launch. The suit--which climaxes several months of growing concern over the safety of the launch--will argue that the launch will endanger the public because an accident could release 48 pounds of highly radioactive plutonium 238 carried aboard Galileo.
The plutonium is used to generate electric power to run Galileo's many components.
"We thought it was a terrible idea" to launch the shuttle Atlantis with Galileo and its radioactive generators in its cargo bay, said Lanny Sinkin, an attorney with the institute. National Aeronautics and Space Administration officials have said the plutonium is packaged in such a way that even an explosion like the one that destroyed Challenger would not likely release significant amounts of the deadly substance, but Sinkin believes the risk is just too great.
The battle promises to be a bitter one, and it has even divided the community that would normally be expected to stand united against a launch carrying radioactive materials.
"After going through mountains of material and soul-searching, I am comfortable with the launch," said Steven Aftergood, senior research analyst with the Federation of American Scientists. Aftergood, who has led the fight to block the use of orbiting nuclear reactors, has personally watched some of the many tests that NASA has used to evaluate the safety of the generators. He said he is "persuaded that the safety risks are small and the scientific payoffs are large."
"I hope to see it go forward," he said.
"We believe it is safe or we wouldn't propose to launch," said John Casani, longtime manager of the Galileo program and now a top executive with NASA's Jet Propulsion Laboratory in Pasadena.
Donald Williams, who will command the Atlantis, said he isn't worried.
"We really have looked at this quite a lot, and I'm convinced in my own mind that it's absolutely safe to fly," Williams said at a recent Florida press conference.
Others, however, are not convinced.
"After the Challenger explosion, Chernobyl and the Valdez accident, we have learned that technology can go terribly wrong," Bruce Gagnon of the Florida Coalition for Peace and Justice said. The coalition is expected to be a party to the suit.
The suit will challenge the adequacy of NASA's environmental impact report, which declares the risk minimal. A federal interagency panel, however, does not rule out the possibility that some cancer deaths could occur if the plutonium is somehow pulverized and released into the environment.
The Atlantis is scheduled for launch Oct. 12. If the suit delays the launch past Nov. 24, the mission will have to be postponed for 18 months because it will be that long before the planets are aligned in a way that would make the encounter possible.
Earlier this month the White House Office of Science and Technology formally approved the launch, setting the stage for the coming legal skirmish.
NASA's opposition has been motivated partly by the space agency's lack of credibility in the field of risk-benefit analysis, as demonstrated by the Challenger disaster, and partly by defection by some respected members of the space community. Richard Cuddihy, a radiation expert and a member of the panel that recommended that the White House give its required approval for the launch, has filed a minority report claiming that the launch "puts a large number of people at risk."
"Our real bottom line is, go find an alternative to the plutonium," Sinkin said.
But NASA and independent experts contend that there is no alternative. Galileo, like 22 other space probes launched with radioactive generators, will operate in areas so far from the sun that solar energy is not practicable.
Galileo will have two "radioisotope thermoelectric generators," each powered by 24 pounds of plutonium 238. As it decays, the plutonium gives off heat that is converted directly to electricity.
The same type of power plant was used aboard the Voyager 2 spacecraft, which recently capped a 12-year tour of four outer planets last month when it zipped past Neptune.
But unlike all the other space probes with nuclear generators, Galileo is to be the first launched by the shuttle. The fight to block the launch is fueled largely by memories of the Challenger fireball over the Florida coast four years ago.
Although 22 spacecraft using a total of 38 radioisotope generators have been launched, the record is not without its blemishes.