31 July 2012
World Nuclear News, the information arm of the World Nuclear Association that seeks to boost the use of atomic energy, last week heralded a NASA Mars rover slated to land on Mars on Monday, the first Mars rover fueled with plutonium.
"A new era of space exploration is dawning through the application of nuclear energy for rovers on Mars and the Moon, power generation at future bases on the surfaces of both and soon for rockets that enable interplanetary travel," began a dispatch from World Nuclear News. It was headed: "Nuclear 'a stepping stone' to space exploration."
In fact, in space as on Earth there are safe, clean alternatives to nuclear
power. Indeed, right now a NASA space probe energized by solar energy is on
its way to Jupiter, a mission which for years NASA claimed could not be
accomplished without nuclear power providing onboard electricity. Solar
propulsion of spacecraft has begun. And scientists, including those at NASA,
have been working on using solar energy and other safe power sources for human
colonies on Mars and the moon.
In its July 27 dispatch, World Nuclear News noted that the Mars rover that NASA calls Curiosity and intends to land on August 6, is "powered by a large radioisotope thermal generator instead of solar cells" as previous NASA Mars rovers had been. It is fueled with 10.6 pounds of plutonium.
"Next year," World Nuclear News continued, "China is to launch a rover for the Moon" that also will be "powered by a nuclear battery." And "most significant of all" in terms of nuclear power in space, it went on, "could be the Russian project for a 'megawatt-class' nuclear-powered rocket." It cited Anatoly Koroteev, chief of Russia's Keldysh Research Centre, as saying the system being developed could provide "thrust ... 20 times that of current chemical rockets, enabling heavier craft with greater capabilities to travel further and faster than ever before." There would be a "launch in 2018."
The problem -- a huge one and not mentioned whatsoever by World Nuclear News -- involves accidents with space nuclear power systems releasing radioactivity impacting on people and other life on Earth. That has already happened. With more space nuclear operations, more atomic mishaps would be ahead.
NASA, before last November's launch of Curiosity, acknowledged that if the rocket lofting it exploded at launch in Florida, plutonium could be released affecting an area as far as 62 miles away -- which includes Orlando. Further, if the rocket didn't break out of the Earth's gravitational field, it and the rover would fall back into the atmosphere and break up, potentially releasing plutonium over a massive area. In its Final Environmental Impact Statement for the mission, NASA said in this situation plutonium could impact on "Earth surfaces between approximately 28-degrees north latitude and 28-degrees south latitude." That includes Central America and much of South America, Asia, Africa and Australia.
The EIS said the costs of decontamination of plutonium in areas would be $267 million for each square mile of farmland and $1.5 billion for each square mile of "mixed-use urban areas." The Curiosity mission itself, because of $900 million in cost overruns, now has a price of $2.5 billion.
NASA set the odds very low for a plutonium release for Curiosity. The EIS said "overall" on the mission, the likelihood of plutonium being released was 1 in 220.
Bruce Gagnon, coordinator of the Global Network Against Weapons & Nuclear Power in Space, which has for more than 20 years been the leading opposition group to space nuclear missions, declared that "NASA sadly appears committed to maintaining its dangerous alliance with the nuclear industry. Both entities view space as a new market for the deadly plutonium fuel. ... Have we not learned anything from Chernobyl and Fukushima?"
Plutonium has long been described as the most lethal radioactive substance. And the plutonium isotope used in the space nuclear program, and on the Curiosity rover, is significantly more radioactive than the type of plutonium used as fuel in nuclear weapons or built up as a waste product in nuclear power plants. It is Plutonium-238 as distinct from Plutonium-239. Plutonium-238 has a far shorter half-life -- 87.7 years compared to Plutonium-239 with a half-life of 24,110 years. An isotope's half-life is the period in which half of its radioactivity is expended.
Dr. Arjun Makhijani, a nuclear physicist and president of the Institute for Energy and Environmental Research, explains that Plutonium-238 "is about 270 times more radioactive than Plutonium-239 per unit of weight."
Thus in radioactivity, the 10.6 pounds of Plutonium-238 being used on Curiosity is the equivalent of 2,862 pounds of Plutonium-239. The atomic bomb dropped on Nagasaki used about 14 pounds of Plutonium-239.
The far shorter half-life of Plutonium-238 compared to Plutonium-239 results in it being extremely hot. This heat is translated in a radioisotope thermoelectric generator into electricity.
There hasn't been an accident on the Curiosity mission. But the EIS acknowledged that there have been mishaps previously -- in this spaceborne game of nuclear Russian roulette. Of the 26 earlier U.S. space missions that have used plutonium listed in the EIS, three underwent accidents, it admitted. The worst occurred in 1964 and involved, it noted, the SNAP-9A plutonium system aboard a satellite that failed to achieve orbit and dropped to Earth, disintegrating as it fell. The 2.1 pounds of Plutonium-238 fuel onboard dispersed widely over the Earth. Dr. John Gofman, professor of medical physics at the University of California at Berkeley, long linked this accident to an increase in global lung cancer. With the SNAP-9A accident, NASA switched to solar energy on satellites.
The worst accident of several involving a Soviet or Russian nuclear space systems was the fall from orbit in 1978 of the Cosmos 954 satellite powered by a nuclear reactor. It also broke up in the atmosphere as it fell, spreading radioactive debris over 77,000 square miles of the Northwest Territories of Canada.
Initiatives in recent years to power spacecraft safely and cleanly include the launch by NASA last August 8 of a solar-powered space probe it calls Juno to Jupiter. NASA's Juno website currently reports: "The spacecraft is in excellent health and is operating nominally." It is flying at 35,200 miles per hour and is to reach Jupiter in 2016. Even at Jupiter, "nearly 500 million miles from the Sun," notes NASA, its solar panels will be providing electricity. Waves Solar power has also begun to be utilized to propel spacecraft through the friction-less vacuum of space. The Japan Aerospace Exploration Agency in 2010 launched what it termed a "space yacht" called Ikaros which got "propulsion from the pressure of sunlight particles bouncing off its sail."
As to power for colonies on Mars and the moon, on Mars, not only the sun is considered as a power source but also energy from the Martian winds. And, on the moon, as The Daily Galaxy has reported:
Still, the pressure by promoters of nuclear energy on NASA and space agencies around the world to use atomic energy in space is intense -- as is the drive of nuclear promoters on governments and the public for atomic energy on Earth.
Critically, nuclear power systems for space use must be fabricated on Earth
-- with all the dangers that involves, and launched from Earth -- with all the
dangers that involves (one out of 100 rockets destruct on launch), and are
subject to falling back to Earth and raining deadly radioactivity on human
beings and other life on this planet.