What is the major theme in the movie the Martian

Isolation, loneliness, independence,

Isolation is one thing, but interplanetary isolation is a whole different ball game. Just ask Mark Watney. In The Martian, we watch as this brave botanist is stranded on Mars, separated from everyone and everything he holds dear. It's a life filled with danger, disaster, and panic, yet the thing that stings the most are his feelings of loneliness. Sometimes they make him feel a little crazy. Sometimes they just make him feel hopeless. At others, they make him wish he had a volleyball for a best friend. As we watch him adapt and fight back against these dark feelings, however, we learn a lot about the powerful effects isolation can have on even the strongest minds.