Today, most if not all science fiction movies are in fact action movies with science fiction elements. Thus _Men in Black_ is an action movie with aliens, _I, Robot_ is an action movie with robots, and so on. There's really no reason a science fiction movie couldn't be a slapstick comedy in an undersea colony, a tear-jerker romantic tragedy on the moon, or an intellectual puzzler with robots. But no, so many SF movies are action thrillers that many people seem not to realize that they can be anything else.
This brings me to _L5: First City in Space_. This is the story of a city in space (the first, in case the title wasn't enough of a clue) which is running low on water. The story is mostly from the point of view of Keiko, an adorable little girl. The basic storyline has been well described by ian-woollard and mikecombs, who seem to have actually paid attention while watching the movie. I will add only that there are no laser battles, no homicidal maniac robots (or homicidal maniac anything else), and no martial arts. Again: THIS IS NOT AN ACTION MOVIE!
Don't get me wrong, I like sci-fi actioners. I really hope that Jackie Chan gets the chance to do his thing in zero-G before he dies or retires. But this isn't the movie for it. This is the movie for adorable little girls and brave scientists and engineers who undertake risky but not flashy missions for the sake of the city their family lives in. The science is (mostly) good, the story (mostly) plausible, and did I mention that Keiko is adorable?
OK, time for my gripe against this movie, aka the reason I didn't give it a 9 or 10. Here also is this comment's spoiler. After the water is secured, Daddy is alive, and Keiko has grown up to be mayor of L5, they have finally built another city. Yeah. One more. In thirty years. According to the NASA/Ames study the makers of this film used for reference, the time for one city to build another was three years, not thirty. Even if we assume that for some reason (politics, scarce water, whatever) it takes five years, this still means that five years after the First City in Space, there would be the Second City in Space, and over the next five years they would EACH build another, for a total of four. In five more years there would be eight, five years later sixteen, then thirty-two, then sixty-four. That's thirty years. So the final shot shouldn't have been two glorious cities side by side, but somewhere from sixty-four to ONE THOUSAND TWENTY-FOUR glorious cities (the 1024 number is thirty years of growth with a three-year doubling time).
Oh, and they should've been making satellite solar power stations.
