Without that material "a lot of things will be shut down and they will stay shut down for a long time," McNutt said. Upcoming NASA missions using plutonium include the overbudget and delayed Mars Science Laboratory, set to launch in 2011, and a mission to tour the solar system's outer planets scheduled for launch in 2020. The last two missions to use plutonium were the New Horizons probe headed for Pluto and the Cassini space probe that is circling Saturn. Plutonium-powered probes last a long time. The twin Voyager spacecraft headed beyond our solar system and launched in 1977 are expected to keep working until about 2020, McNutt said. Solar power is preferable to plutonium because it is cheaper and has fewer safety concerns, McNutt and Allen said. But solar power just doesn't work in the darkest areas of space, including deep craters of the moon. Some have protested past nuclear-powered missions, such as Cassini, worrying about potential accidents. Related Links: |
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