Many children dream of becoming astronauts when they grow up. The thought of blasting off into space, exploring the stars, and experiencing zero gravity is nothing short of exhilarating. Space truly is the final frontier.

For those who do actually pursue their space dream and make it through NASA’s grueling selection process, they’re privy to a whole bunch of stuff us grounded folks aren’t. Here are 20 facts about space life that are sure to wow you!

1. Training to be an astronaut is absolutely brutal, and very few people are able to make it all the way to the end. For example, for one training exercise, trainees were dropped off in the frigid tundra of a Moscow forest with limited supplies and had to survive.

2. Although astronauts are trained underwater to simulate zero gravity, the truth is that the water is nothing like actually being in outer space. Underwater training is mostly used to test astronauts’ skills in a difficult environment.

3. Astronauts have a pretty limited selection of food they can eat, and all of it’s freeze dried. Of all the meals they’re given, the shrimp cocktail is apparently one of the most popular because it keeps almost all of its flavor and texture through the freeze drying process.

4. Burping is a natural human reaction when too much gas builds up in your stomach. However, in space, it’s impossible to burp! Because there is no gravity, the gas can’t rise up out of your body.

5. Nausea is a common feeling when astronauts get to space because of the disorienting feel of zero gravity. To combat this, many of them will spend 10 minutes a day on a specialized machine that trains the brain to adjust quickly to the feeling of weightlessness.

6. Most astronauts carefully choose a selection of music or sound to play every morning to wake up to. The noise acts as a reminder they’re in a space station so they’re not initially startled when they open their¬†eyes.

7. Many astronauts say the secret to being successful is staying humble. Fighting the urge to brag about their missions is hard, considering they actually travel to space, but staying modest goes a lot further.

8. When you’re in tight quarters with other astronauts, you want to be sure everyone has their wits about them. In the off chance someone starts going a little stir-crazy, the official protocol from NASA is to tie them up with duct tape and bungee cords, then administer tranquilizers.

9. Even though Hollywood might make floating around a space shuttle look easy, the truth is that many rookie astronauts struggle with the zero gravity at first and crash into walls. Some of them have even cracked their helmets!

10. One astronaut named Steve Swanson didn’t want to feel left out of a relay race his buddies were running back on Earth, so he joined in! He ran his stretch of the “road” on a treadmill in the space station and called his friends when he was done!

11. Due to the dangerous nature of an astronaut’s job, life insurance policies are outrageously expensive. To get around this problem, many of them sign memorabilia — like their spacesuits — and leave them with family members, so if they die, their family can sell them for cash.

12. Visualizing success is something we’re taught to do in order to achieve positive results in life, but astronauts actually do the opposite and visualize failure. This keeps them on their toes in the event something problematic happens.

13. A lot of people wish they could grow taller, and if they traveled into space, they would! Because of the lack of gravity, astronauts will grow about two inches taller on average, and then shrink back when they return to Earth.

14. If you’re the kind of person who gets a kick out of sneaking up behind people and spooking them, space is the perfect place to do it! Astronaut Jerry Linegar frequently took advantage of the fact there’s very little sound in space, and he would scare the daylights out of his companions!

15. After the grueling pressure and physical exhaustion of a space mission, it can be difficult to acclimate to the world again. When Buzz Aldrin left NASA, he suffered serious bouts of depression, his relationship with his wife ended, and he battled alcoholism.

16. Astronauts are always at risk of injury in the space shuttle, and because they obviously don’t have access to hospitals, each one is trained extensively to deal with medical emergencies.

17. Do you have an urge to become an astronaut? Well, if you do, just know the odds are stacked quite heavily against you. NASA claimed that out of roughly 6,000 applicants, they only choose eight!

18. Breaking wind in a space suit can actually be deadly! The bacteria our intestines produce is flammable, so each suit has a special filter that removes all of the methane and carbon dioxide. 

19. Even though space has no oxygen, it isn’t immune to bad odors. Every space station has an air filtration system, but astronauts have still described the smell of space as metallic, fruity, and some have even likened it to rancid meat. Yikes!

20. Some people might think astronauts are only on the job when they launch into space, but that’s not true at all! When they’re not prepping for a space mission, they spend their days at the Johnson Space Center in Houston, Texas, doing extensive research.