Video: Think You Have What it Takes To Be a NASA Astronaut?

It's no surprise that more than 18,000 people applied to be a part of NASA's 2017 astronaut class. "Astronaut" has long been a dream job for many. However, it's a difficult job and requires a lot of training -- just ask newly returned astronaut Scott Kelly.

So, what do you need to one day blast off in a rocket? To start, at least a 4-year degree in a math, science or engineering discipline.

Potential space-goers will also need to demonstrate physical fitness. Astronauts aboard the International Space Station have to exercise for hours each day to prevent bone and muscle loss in microgravity using equipment like a treadmill that straps users in with 50-pound weights.

Another requirement? A clean bill of health.

"We pull in our docs from the flight medicine clinic and they do a pretty thorough physical," said Anne Roemer, manager for astronaut selection. "Candidates are here for roughly a week. That's a serious physical."

Other things that will help future astronauts include developing dexterity within a bulky spacesuit and a love of Tang.

To learn more about astronaut training, check out the video below from Wired: