"Mission 1: The Application" is an episode from Snoopy in Space. It revolves around Snoopy wanting to be an astronaut.
Snoopy is fighting the Red Baron, and suddenly sees a rocket, and blasted off into space by the Red Baron. Snoopy floats around and has fun. While floating around, Snoopy realizes the earth is below him, causing him to fall down straight on Woodstock. Charlie Brown rushes giving him breakfast, because he is late for the school space play. Snoopy follows, curious about space. However, Lucy stops him from getting into the school. Snoopy sneaks in, and watches the play. The gang teaches them all about space, and Snoopy imagines himself as an astronaut, in a big parade. Lucy catches him again, and throws him out. Snoopy is determined to go into space, so he tries to blast off in his doghouse. That fails, but Franklin states that if you apply to NASA, you could become an astronaut. Snoopy sends his application to NASA. Snoopy waited for a long time, until it came. The letter said that Snoopy "did not meet their standards at this time". Snoopy howls in disappointment, when Sally discovers tickets to go to the Space Center in Houston, encased in the letter. Snoopy is still sad, when Lucy says: "It's not like he would be able to sneak into the astronaut training program". This gives Snoopy an idea. They all go on the bus, bound for Houston, while Charlie Brown runs behind shouting out: "Wait for me!".
When Snoopy tries to get into the school to see the space play, Lucy kicks him out, and says: "No dogs allowed! Or birds!", a reference to Snoopy, Come Home.