How Astronauts Prepare for a Trip in Space4 min read

Have you ever dreamed of going into space? There are many requirements to becoming an astronaut, and even though a candidate might meet all of the education and training requirements, if they’re not physically prepared for the health demands of space travel, they won’t be able to go on a flight. When astronauts know they’ll be going into space, they need to do some extensive preparation to ensure that they’ll be physically safe during the trip.

Requirements to Become an Astronaut

Becoming an astronaut is no easy feat, and since going into space can create significant physical and mental stresses, space flight programs like NASA have strict requirements of potential candidates. In addition to education and experience requirements, NASA astronaut candidates must be in great physical shape. They need to have 20/20 vision, though they may achieve this with corrective lenses. Astronauts need to have blood pressure that doesn’t exceed 140/90 when they’re seated. Additionally, candidates must be between 62 and 75 inches tall.

When selecting astronauts, NASA interviews candidates to make sure that they’re up to the task, both physically and psychologically. Astronauts need a variety of skills, like the ability to work well as a team and a passion for learning. They also need to understand the implications of going to space, like its potential to increase their susceptibility to cancer.

Even though a candidate may pass all of these requirements, that’s just the beginning of getting ready to go into space. They’ll continue to prepare in many other ways to ensure they’re in great health.

Vision Preparation

NASA requires that astronauts have 20/20 vision, so screening for common vision problems may be part of pre-flight preparation. Issues like nearsightedness and farsightedness could interfere with a person’s ability to perform accurate work while in space, and it could even be a safety issue. Many vision issues can be improved with corrective lenses, but it’s important to ensure that the prescriptions are updated and appropriate for an astronaut’s needs before heading into space.

Even if astronauts have perfect vision here on earth, that can change once they get into space. Because our bodies are made up of mostly water, gravity plays an important role in helping to keep that water in the right places while we’re on earth. But if we head into space, that gravity is removed, leaving the water to move about more freely in our bodies. It tends to go to our heads, and that extra fluid can gather in the blood vessels behind our eyes. With increased fluid, the vessels create more intraocular pressure. This pressure can distort vision. And, the longer that a trip to space lasts, the worse those vision issues become.

Gravity can fix this issue, but that’s hard to access in space. Implementing artificial gravity in spacecraft may be the solution to these eye changes that occur, but it will still be important for astronauts to have great vision before they take flight.

Development of Specific Health Goals

Astronauts’ health goals won’t look like everyone else’s. They need to be in peak physical condition in order to reduce the chances that they’ll have a medical emergency while in space. While we might be content to simply get more fit or develop our ab muscles, astronauts need to develop specific health goals that will help to keep them safe during their travels. These health goals need to focus on outcomes that help astronauts to perform their work at their best, rather than helping them to look their best.

The goals will vary between person to person. One astronaut might need to focus on developing physical strength, while another might need to focus on lowering their body mass index, or BMI. Obesity and having a high BMI can increase a person’s chance of developing heart disease or experiencing a stroke. In space, a stroke stands a higher chance of being fatal. Implementing an exercise program and making diet changes while at home may help to keep an astronaut safer when it’s time to take flight.

Muscular and Bone Preparation

Time in space can have many health effects, and it has a significant impact on astronauts’ muscular and bone health. In space, microgravity means that everything is weightless, so our muscles don’t have to work hard to hold us up or perform tasks. Unfortunately, we can lose muscle tone and condition as a result. The same is true of bone mass. While adults over age 50 lose about 10% of their bone mass across a decade on earth, in space, adults lose bone mass much more rapidly. Astronauts can lose as much as 10% of their bone mass in a single year.

To combat this, it’s important that astronauts be as physically fit as possible before they leave earth. This means ensuring their calcium intake is appropriate and performing physical exercise, like jogging, that can help to build both bone and muscle strength.

The road to becoming an astronaut is a long one, but by ensuring that they’re physically fit and ready for the demands of space, an astronaut can increase the chances of their being able to successfully and safely complete their mission.


Image: Pixabay

Sam Bowman
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Sam Bowman writes about science and tech. He enjoys getting to utilize the internet for community without actually having to leave his house. In his spare time he likes running, reading, and combining the two in a run to his local bookstore.

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