Curiosity was the first Mars rover to use a plutonium-powered radioisotope generator.
NASA’s Curiosity rover landed in Gale crater on August 6, 2012. Its Multi-Mission Radioisotope Thermoelectric Generator, or MMRTG, produces electricity from heat released by the radioactive decay of plutonium-238.
Unlike solar-powered rovers, Curiosity can operate during night, winter, and dustier conditions without relying on sunlight. The rover uses a large scientific payload to study rocks, soil, radiation, and the ancient habitability of Gale crater.
Spirit and Opportunity, which landed in 2004, used solar panels. Perseverance also uses an MMRTG, but it arrived later, in 2021. Curiosity’s power system therefore marked an important shift toward reliable long-duration surface operations.