Plenty of children dream of being an astronaut, but very few ever make it to space. In order to become an astronaut one has to be good at everything, and have something that distinguishes them from the rest of the hopeful space explorers.
"If a student comes to me and says, 'I want to be an astronaut,' I tell them, 'Great: Excel in your coursework, go get a piloting license and learn to play the guitar,'" John Armstrong, a professor of physics at Weber State University, told USA Today.
Between 4,000 and 8,000 people apply to be astronauts but only between eight and 35 are selected every four to five years.
On a "busy year" NASA launches about nine shuttles manned by a crew of five. Recently only one American has gotten to hitch a ride with the Russians to the International Space Station, and that opportunity presents itself about three times per year.
In the past NASA favored astronaut candidates with a military background who had spent at lest 1,000 hours flying a jet aircraft. In 1978 NASA decided to consider hopefuls who had at least three years of experience as scientists or engineers. These days NASA is looking at people from even more diverse backgrounds.
"I think our crazy, varied backgrounds contribute to our ability to adapt and learn anything quickly, and then assimilate that knowledge into our skill set," Jeanette Epps, an astronaut and aerospace engineer, who worked at Ford Motor Company and the CIA before joining NASA, told USA Today
All astronauts must have a degree in engineering, math, or science. Most of the extraterrestrial employees hold doctorate degrees, and all have their masters. Some specialized in medicine, biology, chemistry, and even veterinary science.
"If we have 50 astronauts, we have about 50 different educational backgrounds, but they're all technical," astronaut Mike Foreman said.
After an extensive background check, NASA looks at what skills the candidates have.
"Many of them just tend to excel at everything they do," Valerie Neal, curator of space-era artifacts at the Smithsonian National Air and Space Museum, said. "They tend to undertake whatever they do with the full force of their abilities to reach a level of excellence."
If NASA likes what they see they will bring the candidate in for a final interview, only about 100 people make it to this stage each application round.
"It comes down to how much of a positive impression you make on the interview panel," Tom Jones, a former NASA astronaut who flew on four shuttle missions, said. "They size you up in an hour and decide if you're a person they and others would like to work with.
Then the candidate must pass a series of psychological and physical exams which test things like blood pressure and eyesight.
"You have to sort of be lucky just to pass the physical," former astronaut Mary Cleave, who went on two shuttle missions, said.
"Basically, we're looking for nice people who can do the job, pass the medical requirements and can be part of a team for a long duration in an isolated environment," Ross said. "The good news is we've got a lot more great people than we could ever take."