So, you want to leave the planet. Honestly, who doesn't lately? But when you actually start looking into the requirements to be an astronaut, you quickly realize that the gap between "I like Star Trek" and "I am qualified to sit on top of a controlled explosion" is massive.
It’s not just about having "the right stuff" anymore. That 1960s pilot-heavy era is mostly a memory. Today, NASA and partners like ESA or JAXA are looking for people who are basically Swiss Army knives in human form. You need to be a scientist, a plumber, a public speaker, and a very chill roommate all at the same time. If you’re claustrophobic or you can't stand the smell of your own sweat after three days without a shower, stop reading now. Space is cramped. It’s loud. It’s dangerous.
The Academic Bar Is Higher Than You Think
Forget the old "college degree" baseline. In the 2020s, the requirements to be an astronaut have shifted toward advanced specialization. You need a master’s degree in a STEM field—science, technology, engineering, or math. This isn't optional. NASA shifted this requirement recently, effectively cutting out thousands of applicants who only held a bachelor's.
But wait. There's a catch. Not all degrees are created equal in the eyes of the selection board.
If you have a degree in social science or nursing, you’re generally out of luck for the pilot or mission specialist tracks. NASA specifically looks for "hard" sciences. We’re talking about biological science, physical science, computer science, or engineering. They also accept a degree in medicine (MD) or osteopathic medicine (DO).
A lot of people ask if they can get around the master's requirement. You technically can, but only if you have two years of work toward a PhD program, or if you’ve completed a nationally recognized test pilot school program. Even then, the competition is brutal. In the 2017 recruitment cycle, over 18,000 people applied. Only 12 were picked. That’s a 0.06% acceptance rate. Harvard looks like a safety school by comparison.
The Professional Grind
Degrees get you in the door. Experience keeps you there.
You need at least two years of professional experience after your degree. For pilots, this translates to at least 1,000 hours of pilot-in-command time in high-performance jet aircraft. If you aren't a pilot, you need to show that you've done something meaningful in your field. This doesn't mean just sitting in a lab. NASA loves "operational" experience.
What does that mean? It means you've worked in high-pressure, high-consequence environments.
Think deep-sea research. Think Antarctic expeditions. Think wilderness EMT work. They want to see that when things go sideways—and on the ISS, they always do—you aren't going to freeze up or wait for a manual. You need to be able to fix a broken CO2 scrubber with a roll of Kapton tape and a prayer while someone is shouting in your ear in Russian.
Physicality and the "Long-Duration" Reality
The physical requirements to be an astronaut have evolved because we aren't just doing 15-minute suborbital hops anymore. We are talking six months to a year on the International Space Station.
- Vision: You need 20/20 vision, but you can have PRK or LASIK surgery to get there, provided at least a year has passed since the procedure with no complications.
- Blood Pressure: It needs to be under 140/90 while sitting down.
- Height: You have to fit in the seats. This usually means being between 58 and 76 inches tall. If you're a giant or very short, the Soyuz or the new Dragon capsules literally might not fit you.
The Psychological "Expeditionary" Skills
This is where most people fail. You can be the smartest person in the room with perfect vision, but if you're a jerk, you’re never going to space. NASA uses a specific set of criteria called "Expeditionary Skills."
They test for things like "Group Living." Can you live in a space the size of a three-bedroom house with five other people for six months without wanting to jettison them into the vacuum?
Self-care is another big one. You have to be able to manage your own stress, hygiene, and workload without a manager breathing down your neck. Then there’s "Followership." Everyone wants to be the commander, but in space, you often have to be the one taking orders perfectly from a 24-year-old flight controller in Houston who has never left the ground.
Beyond NASA: The Private Sector Shift
The requirements to be an astronaut are changing because NASA isn't the only game in town. SpaceX, Blue Origin, and Axiom Space have their own rules.
If you’re a "Spaceflight Participant" (the fancy word for a space tourist), the requirements are basically:
- Do you have enough money?
- Is your heart strong enough to handle 3 to 4 Gs?
- Can you climb a ladder?
But for the professional crews at SpaceX, the bar remains NASA-adjacent. They still want the engineering background. They still want the flight hours. However, they are often more flexible on the rigid government bureaucracy. They might value software engineering skills more than a traditional geology degree, reflecting the automated nature of modern spacecraft like the Crew Dragon.
The International Hurdle
If you aren't a U.S. citizen, you generally can't apply to NASA. Period. It’s a matter of federal law and national security.
However, the European Space Agency (ESA) has its own recruitment cycles. Their requirements are similar but include a heavy emphasis on linguistics. You better be prepared to learn Russian. Even though the relationship with Roscosmos is... complicated... right now, the ISS is still a dual-language environment. Every NASA astronaut spends months in Star City, Russia, learning the Cyrillic alphabet and how to operate the Russian Segment systems.
The Reality of the Training Pipeline
If you actually meet the requirements to be an astronaut and get selected, you aren't an astronaut yet. You are an "Astronaut Candidate" or AsCan.
You spend two years in basic training. You’ll learn T-38 flight operations. You’ll spend hundreds of hours in the Neutral Buoyancy Lab—a giant pool in Houston—practicing spacewalks in a pressurized suit that weighs 300 pounds. You’ll take SCUBA qualifications. You’ll be dropped in the wilderness for survival training just in case your capsule lands in the middle of the Canadian taiga instead of the ocean.
It is grueling. It is exhausting. And there is no guarantee you will ever actually be assigned to a flight. Some people spend a decade in the "office" before they ever see a launchpad.
Taking the First Steps Toward Orbit
If you are serious about this, you don't start by filling out an application on USAJobs.gov. You start years in advance.
Diversify your skill set. If you’re a pilot, start taking biology classes. If you’re a scientist, get your private pilot's license or a SCUBA certification. NASA looks for "overlap." They want the scientist who can fly the plane and the pilot who can conduct a gene-sequencing experiment.
Get comfortable with "operational" stress. Join a search and rescue team. Work on an offshore oil rig. Go to the extremes. Show the selection committee that you have been cold, tired, and hungry, and you still made smart decisions.
Keep your record clean. This sounds obvious, but drug use or certain legal issues are immediate disqualifiers. The security clearance required for this job is intense. They will talk to your third-grade teacher and your ex-spouse.
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Master a second language. Specifically Russian or potentially Mandarin, depending on how the geopolitical landscape for the Lunar Gateway and Artemis missions shakes out over the next few years.
The path to space is paved with paperwork and physical exams. It’s not glamorous until the engines light. But for those who meet the requirements to be an astronaut, the payoff is a view of the world that only about 600 humans have ever seen.
If you're still in school, focus on a STEM major that you actually love, because if you don't make the cut—and statistically, you won't—you still want to be happy doing that work on Earth. If you're already a professional, look at how you can add "operational" layers to your resume. Volunteer for the difficult assignments. Move to the remote field stations. That’s how you build a profile that stands out in a sea of 20,000 resumes.