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 - chronological order
Directed by: Joe Johnston
Starring: Jake Gyllenhaal, Laura Dern, Chris Cooper, Chris Owen
Continuity mistake: When Homer has just been given the gold medal at the National Science Fair, and he turns around to try to spot Werner Von Braun, several of the people in the crowd jump a lot closer to him when he turns back around.
Quentin: They watched us get arrested. We're practically ex-convicts. They'll never dance with us.
O'Dell: Jesus, Quentin, you don't know anything about women.
Trivia: The title "October Sky" is an anagram of "Rocket Boys," the book on which the movie is based.