My children have both decided on careers as astronauts. I plan on holding them to this decision.
Their motivations for heading into space are slightly different.
My daughter wants to become an astronaut so she can explore the moon and beyond.
My son wants to become an astronaut so he can find out what it's like to pee on the moon, a question which led to discussion of gravity, space suits, and waste disposal technology. This conversation only enhanced his desire to become an astronaut, and led to further queries as to what astronauts do when when they have to do more than simply pee. A true scientist, my son.
NASA, kick yourself into gear again and get that space exploration going, because my children will be joining you soon. And I might tag along.