Mars Rover-Plutonium/Sun-and You (I)

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Dear Friends & Visitors/Readers/Viewers,

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As I’ve mentioned in our last post (Aug. 16, 2012), previous Mars missions (Spirit & Opportunity) have relied on solar panels to power the rovers, but exploration was slowed down by dust on the solar panels or little available sunlight during short winter days.  Curiosity Rover is significantly larger and about ten times heavier than previous Martian rovers;

Mars Science Laboratory mockup comparison Curiosity (R)vs. Spirit & Opportunity (L)

it is essentially a robotic science lab, equipped with sophisticated instruments to take ground samples to analyze their chemical make-up in search for signs of life.  A lot of power is needed to operate the testing and communications equipment and to maintain a certain temperature to effectively operate on Mars (where temperature often go far below freezing).  These are the reasons that NASA chose an energy source that relies on the heat generated by decaying plutonium dioxide (fueled with 10.6 pounds of plutonium), the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) by Hamilton Sundstrand Rocketdyne engineers in Canoga Park and the DOE, to run Curiosity.

As the mainstream media applauded the success of Curiosity Rover’s Mars Landing, there was no mention or discussion about the potential serious danger Curiosity has posed for people/life on earth  prior to arriving on Mars.  If you’d refer to our previous post/video (Aug. 16, 2012 of http://sunisthefuture.net), there are definite risks involved during the launch and 7 minutes of terror.

Even in NASA’s Final Environmental Impact Statement (EIS) for the Mars Science Laboratory Mission, it is indicated that there is about 1-in-220 chances ( http://science.nasa.gov/media/medialibrary/2010/11/05/MSL-FEIS_Vol1.pdf )of deadly plutonium being released “overall” on the mission.  This level of risk seems too high for my comfort level.

The question also involves when and how ( if any mishaps involving this plutonium powered space vehicle should occur) the incident should/would occur.   The 1-in-220 chance/likelihood of plutonium being released could impact a good portion of Earth.  In NASA’s Final EIS for the Mars Science Laboratory Mission, it is indicated that: a launch

Atlas V carrying NASA's MSL launched from Cape Canaveral Air Force Station

accident discharging plutonium has a 1-in-420 chance of happening and could “release material into the regional area defined to be within 62 miles of the launch pad,”…an area including well populated Orlando; an accident releasing plutonium in the troposphere, the atmosphere five to nine miles high, is “assumed to potentially affect persons living within a latitude band from approximately 23-degrees north to 30-degrees north.” That would include the Caribbean, across North Africa and the Middle East, parts of India and China, Hawaii, and other Pacific Islands, Mexico, and south Texas;an accident from plutonium fallout occurring above that and before the rocket breaks through Earth’s gravitational field, affected area could cover “anywhere between 28-degrees north and 28-degrees south latitude.”  That involves a band around the mid-section of the Earth including South America, Africa,and Australia.  According to EIS, the cost of decontamination of areas affected by the plutonium would be $267 million for each square mile of farmland, $478 million for each square mile of forests and $1.5 billion for each square mile of “mixed-use urban areas.”  This is in addition to the cost of mission itself of $2.5 billion.

“NASA is planning a mission that could endanger not only its future but the state of Florida and beyond,” declares John Stewart of Pax Christi Tampa Bay, a leader in Florida in challenging the launch. “The absurd—and maddening—aspect of this risk is that it is unnecessary,” says Stewart, “The locomotion for NASA’s Sojourner Mars rover, launched in 1996, and the Spirit and Opportunity Mars rovers, both launched in 2003, were solar powered, with the latter two rovers performing well beyond what their engineers expected. Curiosity’s locomotion could also be solar-powered. NASA admits this in its EIS, but decided to put us all at risk because plutonium-powered batteries last longer and they want to have the ‘flexibility to select the most scientifically interesting location on the surface’ of Mars.” So, I did my home work and found that the solar powered Spirit rover

Spirit Rover on Mars (artist concept:wikimedia)

was active from 2004-2010 when the mission was only for 90-sol (term sol is used by planetary astronomers to refer to the duration of a solar day on Mars).   Definitely, solar powered Mars rover did last a lot longer than it was designed/intended. Let’s take a look at the footage of Spirit & Curiosity, the two rovers powered by solar energy with far more spirit and curiosity than what NASA engineers expected, below:

Of the 26 U.S. space missions listed in EIS that were powered by plutonium since the 1950s, three had accidents. The worst of these three accidents (occurred in 1964) involved the SNAP-9A plutonium system aboard a satellite that failed to achieve orbit and dropped to earth, dispersed 2.1 pounds of plutonium fuel widely over the Earth.  The late medical physics professor Dr. John Gofman of University of CA at Berkeley linked this accident to an increase in global lung cancer.  After the SNAP-9A accident, NASA switched to solar energy on satellites.  Now all satellites and the International Space Station are powered by solar energy.

NASA apparently insisted on using plutonium as the power source on space probes, claiming that solar energy cannot be utilized beyond the orbit of Mars.  But in Aug., 2011, NASA reversed itself with the launch of the solar powered Juno space probe to Jupiter, stating that when the probe gets to Jupiter, “nearly 500 million miles from the Sun,” its panels will be providing electricity.   Upon further investigation, one finds that Scott Bolton, the principal investigator for the Juno mission for the Southwest Research Institute (a NASA contractor) indicated that “the choice of solar was a practical one…No plutonium-powered generators were available to him and his San Antonio-based team nearly a decade ago so they opted for solar panels rather than develop a new nuclear source.”  It makes perfect sense!  If I were designing/working on project that may use either plutonium or solar energy, my natural inclination for self preservation and preservation of human race would be to maximize the chance of solar energy being used in the project, especially if the cost of solar energy continues to drop and efficiency level continues to increase so dramatically.    More discussion will continue in the next post.  Until then….

~have a bright and sunny day~

gathered, written, and posted by sunisthefuture-Susan Sun Nunamaker, sunisthefuture@gmail.com
Homepage: http://www.sunisthefuture.net


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