oktani
Oktani is a fictional element featured in the science fiction novel "The Martian" by Andy Weir. In the story, Oktani is a highly radioactive and unstable element that plays a crucial role in the protagonist Mark Watney's survival. Watney, stranded on Mars, discovers a sample of Oktani in a derelict Soviet MAV (Mars Ascent Vehicle) module. He learns that the element emits a significant amount of heat as it decays, a property he intends to exploit for his own benefit.
The primary application of Oktani Watney devises is as a heat source to keep his habitat warm