There are no gas stations or power outlets in space. That's why NASA's Curiosity rover on Mars—and some other NASA spacecraft that explore the solar system—use something called "radioisotope power."
NASA's Radioisotope Power Systems Program is working with the Department of Energy on ways to make the next generation of radioisotope power systems even more powerful and capable. This video explains more.
If you want to drive a rover on Mars, you have to keep in mind there's no gas station for millions of miles and there's no outlet to plug into for power. That's why NASA's Curiosity rover on Mars—and other NASA spacecraft that explore the solar system—use something called "radioisotope power."
A radioactive substance releases heat as it breaks down or decays. A system that converts that heat into electricity is called a radioisotope power system. These systems get fancy names. Curiosity's power system is called an "MMRTG," multi-mission radioisotope thermoelectric generator.
MMRTGs are reliable and last a long time. Engineers use this material in devices called thermocouples, which are used to generate electricity. One of the thermocouple's shoes is hot and one is cold. This heat, transferred across a big temperature difference, makes electrical charges flow from the hot shoe to the cold shoe and produces an electrical voltage. And this generates useful electrical power.