First and foremost, to become a candidate, you need to be a citizen of a country that is a member of a space agency. For example, to apply with NASA, you must be a U.S. citizen. However, some private space companies may recruit astronauts without requiring citizenship.
Many qualifications, such as educational background, are similar across space agencies. For instance, to apply as an astronaut with the European Space Agency (ESA), you need to have a master’s degree or higher in natural sciences, medicine, engineering, mathematics, or computer science, or you need to have a test pilot license. NASA has similar requirements but also allows candidates to pursue a two-year doctoral degree in these fields.
However, having the necessary qualifications is not enough. To meet the requirements, candidates also need practical experience – at least two years of post-graduate related experience in their research field for NASA or three years for ESA.
NASA’s requirements can also be met with over 1,000 hours of jet pilot flight time. Since English is the language used on the International Space Station, proficiency in English is a must. Additionally, proficiency in other languages like Russian can be advantageous.
Astronauts also need to have a good physical health record. For example, ESA requires medical certification. NASA candidates must be able to pass the long-duration spaceflight astronaut physical exam.
“Typically, as we get close to the end of the selection process, we put them through the same evaluation process that we would use to assign a current astronaut to a mission, just to make sure that they would meet the criteria to be assigned to a spaceflight mission,” said Anne Roemer, NASA’s astronaut selection manager.
Mental health is as crucial as physical health. Astronauts work long hours in highly stressful situations. They have to be away from their friends and family for months and communicate with people on Earth, which can be challenging.
For example, on the International Space Station, email is available, and astronauts can make video calls, but they only receive audio after the call ends, and there is usually a several-second delay. Communication with family back home could be even more challenging for missions to Mars.
Dagmar Boos, the head of the selection organization, said, “In the selection process, we check, through psychological tests and other tools, the mental stability of the person, especially if there are any signs of instability,” such as psychiatric disorders. This mental stability is essential for both the individual astronaut and the overall crew’s safety, Boos added.
These are the minimum requirements, but to be selected as an astronaut, it takes much more. Over 18,000 people applied for NASA’s astronaut class in 2017, but only 12 were chosen.
One quality the selection team looks for is a balance between leadership ability and being a team player. Experience in challenging environments like the Arctic or deserts can attract evaluators further, Boos said. She also seeks individuals who take responsibility for others’ lives, such as being part of a rescue team.
In addition to spaceflight, astronauts have technical roles on Earth and are the face of the space program, so they need to be adaptable to various contexts. Roemer said, “We’re looking for well-rounded individuals. That could include professional achievements, hobbies, and interests.”
Lastly, astronauts must collaborate with each other in a skilled and intelligent manner. Roemer stated, “The ultimate goal is going to Mars, and that’s a fairly long mission. They’re trying to assess, will I be able to work well with this person and ensure that we have a successful mission?”