Revealing mistake: When Homer placed the rocket on his fence and lit it his friend asked "Should we get behind somethin'?" That's when the rocket explodes. When you see them fly back you don't need to slow motion it because you can clearly see the wires attached to their backs.
October Sky (1999)
1 revealing mistake
Directed by: Joe Johnston
Starring: Jake Gyllenhaal, Laura Dern, Chris Cooper, Chris Owen
Continuity mistake: When Homer is walking to Snake Root, he has a rolling pin in his box. You can see the pin change positions in the box.
Principal Turner: Miss Riley, our job is to give these kids an education.
Miss Riley: Mmm-hmm.
Principal Turner: Not false hopes.
Miss Riley: False hopes? Do you want me to sit quiet, let 'em breathe in coal dust the rest of their life?
Principal Turner: Miss Riley, once in a while... a lucky one... will get out on a football scholarship. The rest of 'em work in the mines.
Miss Riley: How 'bout I believe in the unlucky ones? Hmm? I have to, Mister Turner, I'd go out of my mind.
Trivia: Homer Hickam's father's name is actually Homer Hickam Sr.; in the movie, the father's name was changed to John. The assumption would be that the name was changed in the movie to avoid confusion between father and son.