http://www.slate.com/articles/arts/movies/2015/10/matt_damon_in_the_martian_reviewed.html

A few dozen days (or, as a rotation of the planet is referred to in NASA jargon, “sols”) into his lonely survival ordeal on Mars, the stranded astronaut Mark Watney (Matt Damon) delivers a kind of mission statement into the video log he’s recording for posterity. Faced with the challenge of finding or creating enough food and water to survive the four years until the next mission is scheduled to reach the red planet, Mark decides, with the beleaguered optimism of a born survivor, to “science the shit out of this.”