Go read it. For real. It’s funny as hell.
The guy uses pirate-ninjas as a measurement because “Kilowatt-hours per sol” was a “pain in the ass to say.”
For real, though. The book is about an astronaut who is stranded on Mars after a mission gone wrong and about his attempts to stay alive until the next mission can arrive or until he can be rescued. It’s not the long, drawling, “is it even worth it” story that it might sound like. Never losing his desire to live, Mark Watney (the astronaut in question) literally keeps himself alive using whatever is laying around. I’ve seen a few complaints that she science in the book isn’t very accurate, but it’s my understanding that Weir is devoted hobbyist of subjects like relativistic physics, orbital mechanics, and the history of manned spaceflight. Hobbyist doesn’t sound very encouraging, but it seems like he went very much out of his way to make sure his stuff was sound.
Either way, it’s easy to let the science go because he makes it accessible to an audience who may not have the same hobbies as himself. I found myself wanting more when the book ended, and I guess that’s a pretty good sign.