My parents have formative memories of watching the moon landings as kids, and I of watching the space shuttle. As someone who ended up where I am in large part due to my curiosity about the world growing up, reading of OP's kid watching a rocket launch, thinking critically about what they're seeing, and learning more about the world from it is a joyous thing.
I expect many kids to know that from cartoons, but perhaps my kids whatch weird cartoons. Anyway, the cartoons sometimes have the details wrong, so it's nice to talk about that.