Mark Watney is an American botanist and mechanical engineer on the Ares 3 mission to Mars. He is stranded alone on Mars, and Watney’s narrative point of view is written as his mission log. He begins keeping the record on the first day of his abandonment, knowing that by the time anyone reads it, he may have perished: “I don’t even know who’ll read this. I guess someone will find it eventually. Maybe a hundred years from now” (1). The log begins on sol 6 of the mission. (Throughout the log, passage of time is given in sols, or Mars days—slightly longer than Earth days and equivalent to 24 hours, 39 minutes, and 35 seconds).

Watney knows he is alone because the Mars ascent vehicle (MAV) for the Ares 3 mission is gone, which means the rest of the crew must have used it to return to the ship, the Hermes, which was in orbit above Mars. He relates the specifics of his predicament to the mission log: The Ares 3 crew, of which he is the lowest ranking member, were on the surface of Mars, collecting data and performing their routine duties when a dangerous sandstorm forced them to abort their mission.