- Government agencies will be monitoring for release of plutonium in case of an accident during Saturday's Mars rover launch.
- Launch is scheduled for 10:02 a.m. EST from Cape Canaveral Air Force Station in Florida.
- The new robot draws electricity from the heat given off during the natural decay of radioactive plutonium.
NASA is preparing a robotic probe for launch this weekend to search for life's habitats on Mars, but it is the health of people on Earth that is of immediate concern.
The Mars Science Laboratory, nicknamed Curiosity, is powered by the radioactive plutonium isotope Pu-238, which generates heat as it naturally decays. The heat is tapped to produce electricity for the rover's systems and science instruments.
NASA says the chance plutonium will escape into Earth's atmosphere is very remote, given the perfect track record of the Atlas 5 rocket that will be used to launch Curiosity into space.
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In addition, the 10 pounds (4.5 kilograms) of plutonium inside the probe is laced into ceramic pellets, designed to break apart into pieces, like a coffee mug, rather than disperse as dust into the air. The plutonium also is encased in a capsule of iridium and wrapped in carbon fibers to absorb heat.