Mars Rover Curiosity Gets a 'Reliable' Nuclear Power Source

NASA has revealed more information about the power source of its 'Curiosity' Mars rover, which is scheduled for launch to Mars today.

The organization said that the Mars Science Laboratory mission could be "the most productive Mars surface mission in history," which is partly due to the rover's nuclear heat and power source.

Curiosity's radioisotope power system delivers 110 watts of electricity "reliably" over a period of several years, NASA said. The assembly of the power system was started back in summer of 2008 and was fully fueled "with a ceramic form of plutonium dioxide encased in multiple layers of protective materials including iridium capsules and high-strength graphite blocks" in December of 2008.

NASA stated that it chose a nuclear power source as the solar systems were not good enough to provide full-time communication capability with the rover "during its atmospheric entry, descent and landing regardless of the landing site." A nuclear-powered rover can also last longer, support more payload and go farther than a solar-powered system.

"You can operate with solar panels on Mars, you just can't operate everywhere," said Stephen Johnson, director of Space Nuclear Systems and Technology Division of the Idaho national laboratory, which assembled and tested the power device. "This gives you an opportunity to go anywhere you want on the planet, not be limited to the areas that have sunlight and not have to put the rover to sleep at night."

While electricity is created via "thermocouples, which exploit the temperature difference between the heat source and the cold exterior," NASA said that the system will also supply warmth to the rover and the scientific instruments and experiments on board.

Curiosity is currently set for a launch later today. The mission will focus on the Gale Crater to collect evidence whether the environment on Mars could have supported the development of microbial life at some point. The mission is scheduled to last 23 months.