Andy Weir's best-selling science fiction novel was one of the few that manage to emphasize science almost as much as fiction. The film version, being aimed at a somewhat less cerebral audience, doesn't quite keep that balance, but Drew Goddard's screenplay is an admirable effort to keep up with protagonist Mark Watney's (Matt Damon) determination to "science the shit out of" the problem of surviving after he has been marooned on Mars. And in an age when science has fallen afoul of politics, The Martian nobly attempts to bring some luster to this essential human endeavor. There is also a political undercurrent in the film, namely the hurdles that NASA administrator Teddy Sanders (Jeff Daniels) has to leap in order to achieve the rescue of his stranded astronaut. It's gratifying, too, to see so many actors of color -- Michael Peña, Chiwetel Ejiofor, Benedict Wong, Donald Glover, among others -- given key roles in the effort to rescue Watney, all of them given parts emphasizing their skill and intelligence. On the other hand, there were protests that the ethnicity of some of the characters in the film had been changed. In the novel, for example, the mission director is called Venkat Kapoor, and he is a Hindu. His first name is changed in the film to Vincent, and he's played by Chiwetel Ejiofor, the British actor whose parents were born in Nigeria -- the change is signaled by an explanation that his father was Hindu and his mother was a Baptist. One reason for such protests is that director Scott's previous film was Exodus: Gods and Kings (2014), in which all of the Egyptian and Middle Eastern characters were played by white actors like Christian Bale and Joel Edgerton, a continuation of an old Hollywood tradition that increasingly seems wrong-headed. Fortunately, in The Martian Scott kept the novel's prominent female roles, including mission commander Melissa Lewis (Jessica Chastain) and astronaut Beth Johanssen (Kate Mara).