Washington, 10 October 1997 (RFE/RL) -- The Cassini spacecraft, a high-tech interplanetary explorer, is set to begin its long journey to Saturn on Monday despite heated controversy and protest over its nuclear power source.
Cassini, weighing 5,600 kilograms and standing over 6.8 meters high, was built in a cooperative endeavor with the U.S.'s National Aeronautic and Space Administration (NASA), the European Space Agency and the Italian Space Agency.
The $3.4 billion mission will take 11 years to complete. According to NASA officials, it will take the Cassini spacecraft seven years to reach Saturn which is located about 1,424 million kilometers from the sun. Once it reaches Saturn's orbit, it will undertake a four-year study of the planet's atmosphere, magnetic field, rings and several moons.
The spacecraft, like most of the deep space explorers before it, relies on power supplies of radioactive plutonium -- a highly toxic and dangerous substance.
The plutonium is necessary because it provides heat to convert energy into electric power for the spacecraft. NASA officials say the plutonium has been safely contained in specially-made armor and compressed into a non-pulverizing ceramic form so it cannot be inhaled in the event of an accident.
NASA says it spent seven years preparing a comprehensive safety analysis report and completed two separate processes to address the environmental and safety aspects of the mission.
After reviewing the safety report, John Gibbons, the director of the U.S. Office of Science and Technology Policy, issued a statement that said: "NASA and its interagency partners have done an extremely thorough job of evaluating and documenting the safety of the Cassini mission. I have carefully reviewed these assessments and have concluded that the important benefits of this scientific mission outweigh the potential risks."
But anti-nuclear activists say the risk is far too great, pointing out that Cassini is powered by 32.5 kilograms of plutonium. Critics say it only takes 0.45 kilograms of plutonium, if uniformly distributed, to hypothetically induce lung cancer in every person on Earth.
Bruce Gagnon, a member of an anti-nuclear organization called the Florida Coalition for Peace and Justice, told RFE/RL that if NASA continues to launch radioactive materials into space, there will be ever more opportunities for accidents.
"It's not that we are just against Cassini. We are against the whole idea of putting nuclear-powered systems and weapons in space," said Gagnon.
Gagnon says his organization has little faith in NASA's reassurances of safety, adding that NASA has continually and arbitrarily changed it figures and statistics on safety matters, including the Cassini spacecraft.
Gagnon says his organization believes Cassini could have been re-designed to utilize solar power instead of relying on plutonium as a power source.
But Doug Isbell, a Public Affairs Officer for NASA, told RFE/RL that those kinds of suppositions are "simply incorrect."
Isbell says NASA scientists and engineers did explore the possibility of using solar power on Cassini, but concluded it was not feasible.
"To do a mission like Cassini with solar power would require solar panels the size of two tennis courts. It would be too heavy to launch and too heavy to operate around Saturn. We are continuing our research into solar power technology, but we don't see it being applicable to flights to the outer planets for many years." Said Isbell.
Isbell says that scientists and researchers at NASA believe the mission is "extremely safe" and adds that the U.S. Energy Department, and a number of other independent safety experts conducted exhaustive tests and concluded that the plutonium is safely contained on the spacecraft.
But that is little consolation for Gagnon.
"The space program goes forward at its own peril because if there is ever an accident with this stuff -- we are going to close the space program down," said Gagnon.
The launch of Cassini is scheduled for the afternoon of October 13 from Cape Canaveral Air Station in the southeastern U.S. state of Florida.