Joe Johnston, the director of "October Sky", made a significant amount of changes to the movie from the book. He changed the way the characters interacted with one another, the scenes themselves, and the character's moods. The changes made me dislike the movie more than the book.
The way the characters interacted with one another was more distant than in the book. In the movie it was mostly about Sonny. The "rocket boys" didn't participate as much as they did in the book. Also, the mother and father aren't as distant as they are in the book.
The scenes themselves are different because in most of them there are other characters playing other parts. The "rocket boys" have a scene where they fight and that wasn't even a part of the book. Sonny didn't go to work in the mine and also the "rocket boys" didn't get all of the credit for the science fair in the book like they did in the movie.
The Moods of the characters in the book were more emotional. The movie had less emphasis on the situations. For instance, in the book Sonny and his dad dragged along the argument of Sonny being into rockets, when his father wants him to be into the mineing business. Situations in the movie were delt with by yelling, ignoring, or storming out without resolving anything. The book had more feeling and the problems were worked out through talking.
Joe Johnston made the movie like it had a totally different atmostphere and the characters weren't enteracting as much. I felt like the movie didn't impact enough feeling as the book did and I, personally, enjoy having a movie where it's just like book. Joe Johnston had a great idea for the movie. I just happened to like the book better.