What NASA insisted for decades could not be--a spacecraft using solar energy rather than nuclear power going beyond the orbit of Mars--will be proven false next Monday, July 4th, Independence Day, when the solar-energized Juno space probe arrives at Jupiter.
NASA had maintained that to provide on-board power and heat on spacecraft in deep space, plutonium-powered systems were required--despite the disaster if there were an accident on launch or in a fall back to Earth and the plutonium was released. I broke the story 30 years ago about how the next mission of NASA's ill-fated Challenger shuttle was to involve lofting a plutonium-powered space probe and I have been reporting in articles, books and on television on the nuclear-in-space issue ever since.
If the Challenger accident did not happen in January 1986 but the shuttle exploded on its next scheduled mission, in May 1986, with the plutonium-powered space probe in its cargo bay, the impacts could have been enormous. Plutonium is the most lethal of all radioactive substances.
Still, when NASA re-scheduled the two plutonium-powered missions it had planned for 1986--one the Galileo mission to Jupiter--it not only publicly declared that plutonium systems to provide on-board power for space probes in deep space were necessary but swore to that in court.
Opponents of the Galileo mission brought suit in U.S. District Court in Washington, D.C. in 1989 seeking to stop the nuclear-energized Galileo shot because of its public health danger in the event of an accident, and they pressed NASA and the U.S. Department of Energy (DOE) on the availability of a safe energy alternative. NASA and DOE officials swore that only nuclear power would do that far out in space, that solar energy could not be harvested beyond the orbit of Mars.
And now comes NASA's own Juno spacecraft energized by solar energy functioning in deep space. Indeed, NASA acknowledges, "This is the first time in history a spacecraft is using solar power so far out in space." http://www.nasa.gov/mission_pages/juno/news/juno20110527.html
Says Bruce Gagnon, coordinator of the Global Network Against Weapons and Nuclear Power in Space: "All during out campaigns to oppose NASA plutonium launches during 1989, 1990 and 1997"--when NASA launched its Cassini space probe with the most plutonium NASA ever used in a power system on a spacecraft--"the space agency maintained in court and in the media that solar would not work as an on-board power source in deep space. Then, in part because of grassroots pressure from around the planet, NASA decided to use solar on the deep space Juno mission."
"To this day," Gagnon went on last week, "NASA still maintains that it must use deadly nuclear devices on some of its space missions--further evidence that the nuclear industry maintains a stranglehold on the space agency. The nuclear industry mistakenly views space as a new market for its toxic product that so many have rejected back here on Earth."
Gagnon added: "We will continue to organize to stop the nuclearization of space--and we will use NASA's own Juno mission as evidence that the bad seed of nuclear power is not essential for space exploration."
The Global Network--www.space4peace.org--established in 1992, is based in Maine.
Juno is not a minor space mission. As NASA states on its Juno mission web page--http://science.nasa.gov/missions/juno/-- "The primary scientific goal of the Juno mission is to significantly improve our understanding of the formation, evolution and structure of Jupiter. Concealed beneath a dense cover of clouds, Jupiter, the archetypical 'Giant Planet,' safeguards secrets to the fundamental processes underlying the early formation of our solar system. Present theories of the origin and early evolution of our solar system are currently at an impasse. Juno will provide answers to critical science questions about Jupiter, as well as key information that will dramatically enhance present theories about the early formation of our own solar system."
Juno will, as of Monday, have flown nearly 2 billion miles to reach Jupiter. It was launched from Cape Canaveral, Florida on August 5, 2011. It did a "slingshot maneuver" or "flyby" of Earth in October 2013 to increase its velocity. It has been flying at 60,000 miles per hour. It will orbit Jupiter more than 30 times doing scientific observations.
And although sunlight at Jupiter is just four percent of what it is on Earth, Juno's solar panels, manufactured by Spectrolab, a division of Boeing, will be able to continue to harvest solar energy. Its passes will include bringing it closer to Jupiter than any mission before.
On its current "Where is Juno?" page, NASA reports: "The Juno spacecraft is in excellent health and is operating nominally." www.nasa.gov/mission_pages/juno/where
The solar energy on 66-foot wide Juno is being generated by three large solar panels. They convert sunlight to electricity at a 28 percent efficiency rate. That's a little over the 25 percent efficiency rate of the better photovoltaic rooftop panels now being widely used for electric power on Earth. The cost of the mission is $1.1 billion.
Says NASA on its website: "To answer our fundamental questions about origins we especially need to know Jupiter's internal structure and global water abundance. Juno will map the internal structure by studying its influence on the planet's gravitational field with unprecedented accuracy. The water abundance will be determined by microwave radiometers that will detect thermal radiation from deep atmospheric layers, a completely new approach. Water ice brought most of the heavy elements to Jupiter. Knowing the water abundance will tell us the original form of that ice and hence help define the conditions and processes in the original cloud of dust and gas that led to the origin of Jupiter. Those same conditions and processes were forming other planets too. Because this enormous planet contains most of the water in the solar system we can expect this investigation to help us understand the origin of the life-giving water on Earth."