Astrosmurf, Paperback/Peyo

When one of the Smurfs wants to travel to outer space, he tries to build a rocketship, but it fails to get off the ground and he grows depressed. Papa Smurf and the other Smurfs make a plan in order to cheer him up: putting him to sleep and waking him up in an elaborately staged ``planet`` filled by other Smurfs pretending to be aliens