The movie is set in the year 2035, when the crew of Ares III leads a mission on Mars. At the 18th sol of their 31-sol expedition, an intense dust storm hits the crew. The team decides to head back to their orbiting vessel, Hermes. Mark Watney gets hit by a debris and loses consciousness. Under the command of Melissa Lewis, the crew escapes from the perils of the storm without him.
After the storm, Mark Watney regains consciousness. He discovers that his oxygen supply is depleting. With some injuries caused by the storm, Mark makes it to Hab, the Earth’s living quarters and base of operations on Mars. Mark realizes that there is a piece of metal blocking the wound on his stomach. He also knows that rescue won’t probably come until after four years. To survive such a long time, Mark improvises and uses the available resources around him to construct a small farm and build a source of water made from oxidized rocket fuel. Mark also makes video logs of his daily activities and uses a rover for his journeys across Mars’ surface.
On the other hand, the director for the mission on Mars, Vincent Kapoor, and a satellite planner named Mindy Park, discover through satellite images that Mark Watney is alive. They decide to try communicating with Mark. After being informed of the situation, the director of NASA, Teddy Sanders forbids Mitch Henderson, the flight director of Hermes, from informing the other members of Mark’s team that he survived. In Mars, Marks tries to communicate with people on earth through the Pathfinder probe. Because of this, Mark is able to make conversation with the JPL team on Earth.
As days pass by, a plan to save Mark is conceived by Henderson and JPL director Bruce Ng. They decide to send a space probe to Mars filled with supplies enough to last until the arrival of Ares IV. Things go awry when Sanders decides to launch the probe without inspecting the space craft. What happens is that the probe explodes while in Mars, Watney’s potato farm is destroyed.
The people from NASA and Watney become hopeful again when the China Space National Administration offers their help. CNSA offers a space booster that can either send Hermes back to Mars more quickly or directly deliver supplies to Mars. After a much long debate, it is decided that the booster offered by CNSA will be used to redirect Hermes to Mars using the Earth’s gravity to hurl the craft towards the planet.
As Hermes reaches Mars, Watney must make his towards the aircraft. Using a Mars Ascent Vehicle, Mark Watney escapes Mars but experiences some technical difficulties before he can reach Hermes. The same goes for the space craft as the time and speed of the vehicles do not coincide with Watney’s escape. After fiddling with the mechanics of their own space crafts, Mark Watney and his crew reunite.
The movie ends with Mark Watney returning to earth. He starts his new life as a survival instructor for new hires for the astronaut program of NASA.