 In 2035, the crew of the Ares III manned mission to Mars is exploring the Acidalia Planitia on Martian solar day (sol) 18 of their 31-sol expedition. An unexpectedly strong dust storm threatens to topple their Mars Ascent Vehicle (MAV), forcing them to hastily leave the planet. During the evacuation, astronaut Mark Watney is struck by debris and lost in the storm; the last telemetry from his suit indicates no signs of life. With Watney believed dead, mission commander Melissa Lewis orders the remaining crew to return to their orbiting vessel Hermes without him.
