Mars rover Curiosity powered by nuclear energy

The latest Mars rover has ditched the solar panels used in other missions and has opted instead for nuclear. Why this energy source makes sense on Mars and for this mission.
Written by Kirsten Korosec, Contributor

NASA's latest Mars rover, which launched Saturday from Cape Canaveral, will be loaded with some of the most advanced scientific gear ever used on the surface of the red planet. And everything from its ChemCam, which identifies chemical elements using an invisible infrared wavelength, to its rock vaporizing lasers will all be powered by nuclear energy.

This isn't the first space mission that has used nuclear power. In fact, it's the 28th, according to U.S. Energy Department. But it marks a change within the Mars rover program. The previous two rovers Spirit and Opportunity, which launched in 2003, were equipped with gallium-arsenide solar panels, a specialized niche product that requires very high production per square inch, the NYT Green Inc. blog recently noted. The panels worked, although there were challenges, most notably the dust storms that would blot out up to 90 percent of the sun.

Both Spirit and Opportunity carried lithium-ion batteries to store up to 140 watts of produced power. This isn't much on Earth, where 140 watts is enough to power a desktop computer and monitor, NYT reported. On Mars, it was enough to run the radios, cameras and other equipment as well as the vehicle itself.

The nuclear power packs used to operate Curiosity and space missions before it aren't actually reactors. Meaning they don't split atoms. The rover Curiosity is equipped with the Energy Department's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). The system, which is designed to allow the rover to run where the sunlight is too inadequate that solar panel is impractical, uses heat produced by the natural decay of plutonium-238 to generate 110 watts of electricity. The plutonium 238 is a manufactured isotope that has a radioactive decay that is so fast it glows red hot. The plutonium is toxic. However, the material cannot be used in a bomb.

The electricity that's produced will be used to provide continuous power to the rover and maintain operating temperatures for its 11 scientific instruments, the Energy Department said. Curiosity will investigate whether the Gale Crater on Mars has ever offered environmental conditions that support the development of microbial life. Curiosity is expected to land on Mars in August 2012 and carry out its mission over 23 months, the DOE said.

Photo: NASA


This post was originally published on Smartplanet.com

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