On a dare a naive orphan tries to get aboard a legendary space ship, and back to the orphanage before dinner with a "souvenir" from the ship or the two bullies who made the dare will smash his model space ship.

Thanks for the input. ... True he is ridiculed for playing with his toy, by the bullies. ... Also, I don't think I've mentioned this, and I've found no room for it in the logline, as I still try to keep it fairly short, but the story is supposed to be set in a time and place (not Earth) where and when space ships are commonplace. But the ship in question is special, as it belongs to a hero who is so legendary that most people think he doesn't actually exist. And he has to get through this busy space port to get to the ship, where there are many dangers, with ships taking off and loading and unloading going on. And maybe some shade characters, that I'm thinking of adding that the kid can help put a stop to, as some of you suggested he becomes a bit of a hero himself.

You could ditch the bully motivation and the dare all together, and go with a more Close Encounters of the Third Kind take on it; where something happens to the boy he gets a glimpse of the ship etc., and then life can never go back to normal until he gets on the ship. If getting on the ship is the goal the bullies could stand in his way instead. Maybe his fascination with his favorite toy (that he has been ridiculed for) has had a higher meaning all along...maybe...just maybe...he is meant to get on that ship!
Just another direction.

OMG, you're right. Of course the protag will want to stay on board and travel along with the space ship.

You've helped me figure out the ending!

I hadn't decided if he would actually meet the owner of the ship, his hero ? a Flash Gordon/Buck Rogers type of hero ? and he will ask to stay on board, and even make a very good case. But the owner will turn him down this time.

This whole story is a bit of back story for another story that I've already written a first draft of, which ends with the orphan character, as an adult (early twenties) getting to travel along on the ship in the end.