Why You Should Worry About Space and Health
When you think of the most extreme environments for human survival, space usually comes to mind. After all, astronauts can't just pop into a medical clinic when their health starts to deteriorate in the vacuum of space. But what about getting back down to Earth? We know that returning from space is hard on the human body—it takes some time for astronauts' bodies and minds to adjust back to gravity after spending months or years in microgravity or weightlessness. Luckily, scientists have found ways to measure these changes so they can better understand how best to help astronauts adjust once they return home from their missions (or maybe even before).
How Does Spaceflight Affect the Human Body?
- Lack of Gravity: The human body evolved in an environment where there's gravity, so when you're in space and not just floating around, your body has to adjust. You'll feel lighter than normal and will have a different sense of balance because your inner ear—which senses movement through the fluid surrounding it—isn't getting any signals from gravity telling it that you're moving.
- Microgravity: On Earth, we stand up because our muscles push against bones that are firmly attached to our feet; but in microgravity on the International Space Station (ISS), this doesn't happen at all! Since there's no gravity to give us support, astronauts need special shoes with springs inside them that help keep their legs stable while they walk (and also help prevent blisters).
- Bone Loss: Without gravity pulling down on your bones for long periods of time like it does here on Earth, they can weaken over time as calcium leaves them due to lack of use. This can lead to osteoporosis (weak or brittle bones) or fractures if astronauts don't exercise regularly enough while they're working out in space.
Bone loss is a major concern during long periods of weightlessness.
The human body is a beautiful work of art, but it's not perfect. There are many physical changes that occur when a person leaves Earth's gravitational pull and enters space. One such change is bone loss, which occurs when there is insufficient gravity to keep our bodies strong. Without gravity, muscle mass is lost. Additionally, calcium ions (the building blocks of bones) are pulled out of the bones after being released from their storage places in the cells. This can lead to osteoporosis—a condition in which the bones become porous and fragile over time due to lack of calcium stored within them—and other serious problems like muscle atrophy and weak muscles that cannot support you properly when walking or standing upright for long periods of time.*
Astronauts who spend months on the ISS can experience substantial vision changes.
It's no secret that astronauts often experience changes in their vision while in space. Changes in the shape of the eye and lens are common, as is a color change to sclera (white part of the eye). However, it's also possible for astronauts' eyes to shrink or grow larger by up to 50%! This can happen due to fluid redistribution.
- Astronauts who spend months on the ISS can experience substantial vision changes.*
Microgravity messes with the inner ear, making balance and orientation a problem for astronauts.
Your inner ear is a complex system of organs that helps you maintain your balance, sense of direction and orientation. It's sensitive to gravitational pull, acceleration and movement. It's also sensitive to sound. That's why when you're in space—and away from the gravitational force of Earth—the way astronauts orient themselves becomes difficult: they lose their sense of up and down as well as what direction they're facing relative to Earth.
This happens because the fluid in your inner ear moves around differently in microgravity than it does on Earth; it sloshes around inside your head instead of staying pressed against the walls of your inner ear by gravity (which acts like a squeegee). This ability to move freely causes problems when trying to determine what "up" means for an astronaut in space—when there aren't any landmarks like mountains or buildings nearby for reference points with which astronauts can compare their own bodies' orientation.*
Lack of gravity can cause changes to the way the body distributes fluids and blood.
You might not know this, but our bodies are constantly fighting gravity. Every day, they work like little machines to make sure that everything stays where it's supposed to be—from your blood flowing through your veins and into your brain, to all of the interstitial fluid that helps lubricate all of the moving parts in your joints. When you go into space, however, those mechanisms get thrown out of whack:
The body's fluids shift toward the upper body because there's no longer a pull on them from gravity. This can cause increased pressure on the heart and lungs as well as swelling throughout one's body (including around their face). The lower half of an astronaut's body may also experience fluid accumulation due to lack of circulation; if left untreated for too long, these pools can lead to kidney failure or other serious health problems.*
Because this is such a big deal for astronauts who spend extended periods away from Earth (like if we ever want humans living on Mars), NASA has been working hard for decades now on developing ways for spacecrafts' cabins and suits themselves*to retain more moisture.*We'll talk about some solutions later; first let's think about why this happens in general terms:
Psychological health is a concern for astronauts spending months in space.
Space travel can be a stressful experience. Astronauts are not immune to the stresses of long-term isolation, and many astronauts have suffered from depression, anxiety and other psychological issues during spaceflight. They may also suffer from the loss of friends and family, feeling isolated in the vastness of space with only each other for company.
We don't know much about how these factors will affect astronauts living on Mars or on other planets in deep space missions — but we do know that psychological health is something that needs to be taken into consideration when designing such missions."
Spaceflight has some serious consequences for human health, so scientists are looking for ways to monitor human health on long space journeys.
While spaceflight is an exciting prospect for many, it also has some serious consequences for human health. If we want to explore the universe, we need to understand how traveling in space affects our bodies and minds.
Scientists are working hard to find ways of monitoring human health on long space journeys so that they can better understand how astronauts' bodies react to extended periods without gravity or fresh air. They've come up with several innovative ways of tracking mental and physical wellbeing by using sensors that can measure things like heart rate and blood pressure at different points throughout the ship.
But monitoring health on long journeys isn't easy—the challenges are many! Before making it into orbit, astronauts face a whole host of stressful conditions: extreme heat inside their spacecrafts during take-off; loud noises coming from wind roaring over their heads as they blast off into space; rapid acceleration forces when launching rockets into orbit (and then decelerating again when returning home); bone loss due to lack of gravity pulling down their skeletons; muscle atrophy due to not being able to use them properly during prolonged stays aboard spacecrafts...these factors contribute significantly towards shortening an astronaut's lifespan after coming back from such missions (i.e., dying younger).
The human body is an amazing machine, but it has its limits. Spaceflight pushes those limits in ways we’re only beginning to understand. Science is learning more about how the body responds to long periods of weightlessness, and scientists are working on solutions for all of these problems so that we can explore our universe with more confidence and less risk.