nuclear milestone graphic
Mars 2020 Rover_MMRTG

 Multi-Mission Radioisotope Thermoelectric Generator 

The U.S. Department of Energy successfully delivered its latest nuclear power system to the Kennedy Space Center in Florida—the site of NASA’s Mars 2020 launch later this summer. The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) was fueled, built and tested by DOE’s national laboratories to power the mission’s Perseverance rover

Fueling Space Exploration

Perseverance will be the first rover to use plutonium created by Oak Ridge National Laboratory (ORNL). The lab, along with Idaho and Los Alamos national laboratories, is helping NASA beef up its fuel supply for Plutonium-238—an isotope used for deep space missions.

ORNL recently automated part of the production process allowing the lab to produce up to 400 grams of Pu-238 each year, moving closer to NASA’s goal of 1.5 kilograms per year by 2025. 

MMRTG Advantages

Radioisotope power systems (RPS) convert heat generated by the natural decay of Pu-238 into electrical power. The MMRTG will provide electricity for the basic operations of the Perseverance rover and keep the rover’s tools and systems at optimal temperatures. The power system has an operational lifespan of 14 years which surpasses the energy needs of the rover’s year-long journey to, and exploration of, the red planet.

Radioisotope Power System Infrastructure

DOE maintains the essential infrastructure to help fuel, build and test each power system. ORNL provides the heat source materials and hardware for NASA missions. Los Alamos National Laboratory purifies and encapsulates the plutonium-238. Idaho National Laboratory then assembles, tests, and assures the final delivery of the RPS.

The MMRTG, F-2, is the latest power system provided to NASA by DOE in a long-term relationship to accomplish great things in space exploration.

Stephen Johnson
Director of Space Nuclear Power & Isotope Technologies at Idaho National Laboratory

The delivery and installation of the MMRTG completes the RPS production phase of this project. A hot fit check was conducted to test the rover’s system while powered by the MMRTG. A small crew from INL will monitor the power system around the clock until its anticipated launch on July 17th, 2020. 

Next Steps

DOE will continue to support its strong partnership with NASA. Its next MMRTG is set to power the Dragonfly rotorcraft lander mission to explore Saturn’s largest moon, Titan. Since solar energy is not a viable option in Titan’s hazy atmosphere, the MMRTG will play a major role in supplying power to the spacecraft.

Dragonfly is scheduled to launch in 2026.

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