I'm strongly against spoilers -- even saying whether I liked a movie or didn't -- so I won't do that here. But I did want to publicly recognize a thing this movie got exactly right: the large and unremarked-upon role of women and non-white people in a variety of positions in the space program.
The real space program is exactly like that, damn it, and it's nice to see a movie get that so right at last. The movie doesn't call attention to it, they just do it, which is exactly how it should be. (This is surely in part because the source novel does the same; it's just one of many things Weir absolutely nailed.)
It was something I really loved about that work. I drove rovers with people from Italy, from Taiwan, from Mexico, from India, from Ghana. I loved that in part because it felt like being on the bridge of The Enterprise, and also because ... well, it just felt right.
It took me a long time to realize why: it was because in a perfect world, a world in which racism and sexism played no role, that's what the team would look like. High-quality gray matter is distributed without regard to race or sex, so if you just went around the world choosing the perfect people for the work, you'd naturally end up with just that sort of diverse team.
It still wasn't perfect, but it was very very very good, a taste of how the world should be. And will be. Kudos to Ridley Scott for showing us all that world.