The recent news that NASA and the Defense Advanced Research Projects Agency (DARPA) are teaming up to build a nuclear thermal propulsion rocket and test it in 2027 was welcomed by advocates of space exploration. The technology would cut the time for humans to voyage to Mars in half or even more. It would also be useful for deep space planetary voyages, such as the proposed flagship mission to Uranus. NASA has been working on nuclear propulsion for several years.
Linda Billings, a consultant for NASA’s Astrobiology Program and Planetary Defense Coordination Office, is not very thrilled by the news. She tweeted, “The concern here is what could happen on the launch pad, also manufacturing the nuclear fuel: NASA, DARPA Will Test Nuclear Engine for Future Mars Missions.” Billings also writes about space policy, generally from a progressive perspective.
The Bulletin of the Atomic Scientists has a lengthy study of the use of nuclear power in space. One way NASA plans to mitigate the possibility of a nuclear accident during a launch is to only turn on the nuclear reactor after the spacecraft achieves a safe orbit. Also, NASA will only use fissionable materials that cannot be diverted to nefarious purposes, such as creating a nuclear bomb.
Those and other safeguards may not be enough to assuage the fears of environmentalists. In 1997, the launch of the nuclear-powered Cassini probe drew protests and lawsuits.
Theoretical physicist and celebrity scientist Michio Kaku at the time claimed that an explosion on the launch pad could spread radioactive plutonium across Central Florida, potentially cause more than 1 million casualties, NASA countered that the RTG units in the Cassini that used the decay of plutonium for power constituted little to no danger.
The protests and the lawsuits failed. Cassini lifted off without incident. In the fullness of time, the probe went in orbit around Saturn and explored the gas giant and its moons for several years, doing a great deal of good science.
Launch is not the only period of danger when using nuclear material in space. In January 1978, a Soviet nuclear-powered satellite called Cosmos 954 made an uncontrolled reentry and distributed radioactive material over a 124,000 square kilometer area of Canada’s northern region. A joint Canadian and American effort took months to clean up the mess. The accident elicited calls to prohibit spacecraft with nuclear materials in low-Earth orbit. Former Royal Canadian Mounted Police officer Lance Rayner believes that his cancer was caused by his guarding a radioactive piece of the satellite during the crisis.
NASA and DARPA had best be prepared for environmentalist pushback as the launch of their nuclear engine prototype, scheduled for 2027, approaches. Protests, including civil disobedience, should be expected and planned for. Lawsuits will likely be filed. Fortunately, NASA can do several things to prepare.
First, NASA and DARPA should design the nuclear thermal rocket with safety in mind, as much as is practically possible. While the Soviets launched several nuclear-powered satellites in the 1960s and 1970s, the United States launched only one spacecraft powered by a fission reactor, the SNAP-10A, in 1965. No one has launched a nuclear propulsion system into space, although NASA tested a prototype called NERVA on the ground in the 1960s, President Nixon canceled the program when it became clear that humans would not be going to Mars anytime soon.
NASA should be entirely transparent about how it will attempt to prevent a catastrophic spread of radioactive materials in the extremely unlikely event of an explosion on the pad or during the initial launch. The space agency should have plans in place if nuclear material is released, to alleviate damage to life and property.
NASA should educate the public about why nuclear propulsion is not only something nice to have, but is a necessity if human civilization is to spread beyond the Earth on a greater scale than a few explorers. Access to the mineral and energy resources of the solar system would be a boon to all humankind and would be worth the infinitesimal risk of launching nuclear fuel into space.
Nuclear disasters such as Three Mile Island have inculcated many people with a fear of nuclear power. Nuclear energy has its dangers, although to this day science doesn’t know, for example, how much radiation exposure will lead to cancer, even decades later. But nuclear technology also holds a great deal of promise. NASA can help lead a rational discussion, free of hype and doom mongering, on both aspects.
Mark R. Whittington is the author of space exploration studies “Why is It So Hard to Go Back to the Moon?” as well as “The Moon, Mars and Beyond,” and “Why is America Going Back to the Moon?” He blogs at Curmudgeons Corner.