Wow. Yet another dick wastes the time (and therefore money) of one of the most underfunded programs that have broadly benefited us. [one tiny e.g.: we would not be having this discussion here if not for the space program research resulting in more powerful/smaller computers.]
Or some guy just wrote a humorous letter on forged NASA stationery. Which seems more likely. It seems like, if some doofus like the one described in the letter applied to be an astronaut, they'd just send him a form letter or throw the letter away and send nothing.