A space probe with 50 pounds of plutonium aboard--theoretically enough if dispersed to give everyone in the world lung cancer--made an extremely risky low-level "flyby" of the Earth in December 1992.
But you wouldn't have known any danger was involved by reading most of the mainstream U.S. media. Indeed, the New York Times' Dec. 8 account of the Galileo space probe flyby--which occurred later that day--didn't mention the word "plutonium" once, or "nuclear." Nor did the story, by John Noble Wilford, give any indication of concerns expressed by NASA's Jet Propulsion Laboratory, or by General Electric, the manufacturer of Galileo's plutonium-fueled power supply.
GE, in a "Final Safety Analysis Report," said that only after the "successful...escape of the spacecraft from the Earth's gravitational pull" on Dec. 8 would Galileo's plutonium "no longer present a risk to the Earth's population."
The JPL wrote an analysis called "Galileo: Earth Avoidance Study Report," because its scientists were worried about something that had never been attempted in space flight before Galileo's first flyby in 1990--sending a nuclear-powered probe by the Earth in what NASA terms a "slingshot maneuver," using Earth's gravitational pull to increase its velocity. The 1990 flyby was at an altitude of 600 miles; the Dec. 8 approach was at a far closer 185 miles. The JPL considered raising the flyby height, but concluded if it didn't swing that close to the Earth, the $1.4 billion probe wouldn't make it to its destination of Jupiter by 1995.
When Galileo made its closest approach to the Earth on Dec. 8, it was the fastest manmade object ever to buzz the planet—at 33,000 miles per hour. If it had dipped into the 75-mile high atmosphere, it likely would have disintegrated, its plutonium dispersed. Fortunately, this did not happen—even though the craft has repeatedly gone out of whack.
In both March and May of 1991, the probe lost all but what NASA called "essential functions" due to a "stray electronic signal." In April 1991, its main communications antenna failed to unfurl—a problem that has continued to plague Galileo throughout the flyby and beyond.
But Wilford's New York Times story, citing JPL flight controllers, assured readers there was "no chance of an errant plunge into Earth's atmosphere." No reference was made to the JPL or GE reports that acknowledged the danger, or to statements by independent scientists like Michio Kaku, professor of nuclear physics at CUNY, who warned (WBAI, 11/18/92) that a flyby mishap could cause "the most toxic chemical known to science to shower down and a tremendous tragedy for the people of Earth to result." (He also noted JPL reports released after the 1989 Galileo launch that said a solar energy system could have substituted for plutonium power on Galileo.)
Space reporters have long been reluctant to deal critically with the U.S. space program. Wilford, at a talk he gave on "Science and the Media" at Brookhaven National Laboratory in 1991, acknowledged the problem of space reporters not challenging NASA. "There's still a lot of reporters who are groupies," Wilford said. "Some are turned on by rockets and science fiction and they got into it because of that and they tend to be the least critical." Most reporters, he added, had become more skeptical since the 1986 Challenger disaster. Still, he said, "some of the things that NASA does are so great, so marvelous, so it's easy to forget to be critical. You go in and watch pictures of the back of Neptune and stand in awe."
U.S. nuclear space flights are far from over—a major expansion is planned. In 1995, the U.S. plans to launch the Topaz 2 reactor, a Russian-built enriched uranium power plant seen as a prototype for Star Wars reactors. The Cassini probe to Saturn is scheduled to be launched in 1997, and to fly by the Earth with 73 pounds of plutonium at a height of 320 miles. NASA, which opened a Nuclear Propulsions Systems Office in 1991 along with the Departments of Energy and Defense, is also proposing to launch two plutonium-fueled probes to Pluto in 1998.
At the same time, the U.S. is developing rockets that would actually be propelled by nuclear power—a revival of a 1955-1973 venture that was canceled out of concern over nuclear-powered rockets crashing back to Earth. The nuclear rockets, which would have both civilian and military applications, would be built by Babcock and Wilcox, which manufactured the reactor that melted down at Three Mile Island.
"What we have is spaceborne Russian Roulette," declares Bruce Gagnon, co-coordinator of the Global Network Against Weapons and Nuclear Power in Space. Inevitably, if nuclearization of space is allowed to continue, there will be nuclear disaster."
Meanwhile, the press sleeps.
Karl Grossman writes frequently for Extra! on nuclear issues.