• Number 353  |
• January 2, 2012

Reliable nuclear device to heat, power Mars Science Lab

NASA's Mars Science Laboratory mission launched Nov. 26 carrying the most advanced payload of scientific gear ever used on Mars' surface. Those instruments will get their lifeblood from a radioisotope power system assembled and tested at DOE's Idaho National Laboratory. The Multi-Mission Radioisotope Thermoelectric Generator is the latest "space battery" that can reliably power a deep space mission for many years.

The device provides a continuous source of heat and power for the rover's instruments. NASA has used nuclear generators to power 26 missions over the past 50 years. New generators like the one destined for Mars are painstakingly assembled and extensively tested at INL before heading to space.

"This power system will enable Curiosity to complete its ambitious expedition in Mars' extreme temperatures and seasons," said Stephen Johnson, director of INL's Space Nuclear Systems and Technology Division. "When the unit leaves here, we’ve verified every aspect of its performance and made sure it’s in good shape when it gets to Kennedy Space Center."

The power system provides about 110 watts of electricity and can run continuously for many years. The nuclear fuel is protected by multiple layers of safety features that have each undergone rigorous testing under varied accident scenarios.

The INL team began assembling the mission's power source in summer 2008. By December of that year, the power system was fully fueled, assembled and ready for testing. INL performs a series of tests to verify that such systems will perform as designed during their missions. These tests include:

• Vibrational testing to simulate rocket launch conditions.
• Magnetic testing to ensure the system's electrical field won't affect the rover's sensitive scientific equipment.
• Mass properties tests to determine the center of gravity, which impacts thruster calculations for moving the rover.
• Thermal vacuum testing to verify operation on a planet’s surface or in the cold vacuum of space.

The nuclear powered rover can go farther, travel to more places, last longer, and power and heat a larger and more capable scientific payload compared to the solar power alternative NASA studied.

"You can operate with solar panels on Mars, you just can't operate everywhere," said Johnson.

[Nicole Stricker, 208-526-5955,
nicole.stricker@inl.gov]