It’s rare for a work of science fiction to contain much science fact. But in “The Martian,” a very real technology helps keep a very made-up astronaut alive on the Red Planet.

“The Martian” begins with a crew of NASA astronauts on a mission to explore Mars. An unexpected weather event forces the research team to evacuate the planet and leave one of their own behind in the process.

Presumed dead, Astronaut Mark Watney — played by Matt Damon — survives the violent storm and must find a way to subsist on the barren planet until a rescue is possible.

One of Watney’s biggest survival challenges is how he’ll stay warm during the sub-zero Martian nights. His solution is to use a radioisotope thermal generator, or RTG, as a portable heat source.

An RTG contains approximately 4.8 kilograms of plutonium-238 dioxide and works by transforming the heat from the decay of the radioactive isotope into electricity. It is an ideal power source for missions that are too far from the sun to use solar power. It’s also an ideal way for Watney to keep warm.

Oak Ridge National Laboratory (ORNL) is re-establishing its capability to produce plutonium-238. This renewed production will help NASA further its plans for deep-space exploration, including missions to Mars. ORNL also supplies NASA with containment vessels for the plutonium 238, which are called iridium clad vent sets.

If Watney’s predicament were real, ORNL would be playing a vital role in his survival. As the sole source of the plutonium-238 needed for the RTG (and the iridium clad vent sets that contain it) you can thank ORNL for keeping Watney alive.