The problem is that the Hab’s air regulator that decides how ... That all goes in a sealed container, and to keep it all warm during the Martian night, he has some of the power go through ...

The camera on board Pathfinder sent back this photo in 1997 of the Martian environment surrounding the lander's final resting place. After Watney returns to the hab and starts talking with NASA ...

So the movie is missing a few critical scenes, but it's still pretty true to the book (and full of science).