An American astronaut with the NASA Ares 3 mission to Mars, Watney is a trained botanist and mechanical engineer. On sol 6, he is stranded on Mars, and he spends the rest of the novel solving every problem and working every angle to somehow survive and return to Earth. He is an independent thinker and creative problem solver, two characteristics that, in his opinion, are part of the reason he was chosen for the mission. These characteristics—as well as his resilience stemming from a seemingly innate optimism, and a dark, self-deprecating sense of humor—allow Watney to keep moving forward in the face of a seemingly impossible task: surviving Mars, alone.

Watney is the protagonist, and the bulk of the novel follows him as he works toward his goal. The reader is privy to Watney’s innermost thoughts and struggles through his use of his mission log as a record of his struggle. In the mission log, he is brutally honest about his successes and failures as well as the physical and mental challenges he faces. From the beginning, he steadily works toward surviving, and there is really only one place in the text where he considers just giving up and letting the obstacles get the better of him.