In 1950, the American Museum of Natural History's Hayden Planetarium started accepting reservations for the first trip to space, which was part of their publicity campaign for an exhibition called Conquest of Space. As you can imagine, letters came in from all over, requesting reservations on future trips to the Moon, Mars, Jupiter, and beyond. Most of these letters were penned with youthful exuberance by kids from all over the country, who hopefully ended up, at the very least, going to Space Camp. The museum notes that even today "interplanetary tourism is not yet possible."

Click through for some of our favorites—and more on the AMNH's site—including one that reads: "I would like a reservation on the trip to the moon that is supposed to leave in 1975. I am in the 6th grade... by the time the space ship is ready to leave I will be about 36 years old." [via Boing Boing]