Mark used the RTG (Radioisotope Thermometric Generator), basically a big box filled with Plutonium-238, to heat up water for a bath inside the Hab and also on his Rover trip to the Ares IV landing site in order to save energy that would have otherwise been wasted on the heating.

The Hab's airlock malfunctions, depressurizing and damaging the Hab. Watney repairs it, but the Martian atmosphere and temperature have killed his potatoes and sterilized the soil.

Mars mission director, Vincent Kapoor, and Jet Propulsion Laboratory (JPL) director Bruce Ng prepare an Iris space probe to deliver enough food for Watney to survive until Ares IV's arrival. Believing it a low risk, Sanders orders the routine pre-flight safety inspections be bypassed to expedite the probe's launch. The rocket explodes 51 seconds after liftoff.

The Tiayang Shen is a secret Chinese probe that was originally supposed to orbit Venus and Mercury. CNSA (China National Space Administration) gives it to NASA to help save Mark Watney and bring him back to Earth in return for getting one of their astronauts on the next ARES mission.

JPL astrodynamicist Rich Purnell devises an alternative plan: have the Taiyang Shen rendezvous with and resupply the Hermes, which will then use Earth's gravity to "slingshot" back to Mars two years earlier than Ares IV. Sanders rejects the idea, considering it too risky for the Hermes crew. Henderson surreptitiously sends Purnell's plan to the crew; they unanimously vote to implement it, disabling NASA's remote controls and making the course change. Powerless to stop them, NASA concedes the issue.

The "cloak-and-dagger" meeting is dubbed Project Elrond after the Council of Elrond in the Lord of the Rings films. When the code name is questioned, the first character to explain it is Henderson, played by Sean Bean, who also played Boromir in The Lord of the Rings and was present during said council.

During the fly-by Watney is too far from the Hermes to be rescued and decides to puncture the glove on his spacesuit to release pressure and propel himself toward the crew. "I admit it's fatally dangerous," Watney says, "but I'd get to fly around like Iron Man."

While The Martian gets much of its science right, Weir has acknowledged that the massive dust storm that sets the story in motion and leaves Mark Watney stranded on Mars was a bit of poetic license. Since Mars' atmospheric pressure is so low, even a fierce storm like the one shown would do little more than mess up your hair.

The constellation Orion can be seen in almost every shot of space throughout the entire movie. It is even visible in the background of most scenes through the windows of the Hab and Hermes.

The majority of The Martian was filmed on indoor sets in Budapest, Hungary, but many of the exterior shots of Mars were filmed in Wadi Rum, also known as the Valley of the Moon, in southern Jordan. This same location was used for certain shots in the epic Hollywood classic Lawrence of Arabia (1962).