What Happens To Your Body In Space?

Tim Peake is the first British astronaut to set foot in space. 

what happens to your body in space?Photo via Health Europa

After launching off on a Russian Soyuz rocket to the International Space Station on December 15th, last year, the former Army Air Corps officer has spent a month in space, but the spacewalk will undoubtedly be his most difficult challenge.

But what will he be experiencing during his incredible stay aboard the space station? Since Yuri Gargarin made the first manned space flight in 1961, various changes in the human body have been explored, and a large team provides guidance and preparation for astronauts before, during, and after any spaceflight. 

However, if you're planning an out-of-this-world adventure, here are some things to keep in mind according to The Conversation…

1) You deteriorate

The largest organ system in the human body is the skeletal muscle system. Hundreds of muscles are utilized to maintain posture - sitting, standing – and to undertake a wide range of actions under various loading circumstances imposed by Earth's gravitational forces.

what happens to your body in space?Photo via seca

Plasticity is the ability of skeletal muscles to adapt to diverse functions and pressures imposed on them. Space flight, like inactivity, causes skeletal muscle mass (atrophy) and strength loss.

During protracted spaceflights on the International Space Station, 37 crew members witnessed a drop in mean isokinetic strength of between 8% and 17%, according to studies. Both men and women were affected in the same way. This degeneration occurs even when astronauts adhere to a stringent exercise regimen, implying that it has far-reaching consequences for humans embarking on even longer missions, such as missions to Mars. 

After 110 to 237 days in microgravity, data suggests that roughly 30% of muscular strength is lost.

2) …So does your heart

Gravity affects several components of the circulatory system, including the heart. On Earth, the veins in our legs, for example, struggle against gravity to return blood to the heart. The heart and blood arteries, on the other hand, change in the absence of gravity, and the longer the flight, the more severe the changes.

what happens to your body in space?Photo via Bright Side

With microgravity, the size and form of the heart, for example, alters, and the mass of the right and left ventricles decreases. This could be due to changes in myocardial mass and a decrease in fluid volume (blood). In space, the human heart rate (number of beats per minute) is also lower than on Earth. In fact, it has been discovered that the heart rate of astronauts standing erect on the International Space Station is similar to that of those sleeping down on Earth prior to takeoff. In space, blood pressure is also lower than on Earth.

The heart's cardiac output — the volume of blood pumped out each minute – diminishes in space as well. There is also a redistribution of blood in the absence of gravity: more blood stays in the legs and less blood returns to the heart, resulting in less blood being pumped out of the heart. Reduced blood supply to the lower limbs is also a result of muscle atrophy.

The combination of diminished blood supply to the muscles and loss of muscular mass has an impact on aerobic capacity (below).

3) You will lose your fitness

The maximum amount of oxygen that the body can consume during activity is measured by aerobic capacity, which is a measure of aerobic fitness. VO2max and VO2peak tests can be used to determine this. 

what happens to your body in space?Photo via medibank

Aerobic fitness is lowered as a result of changes to the muscles and cardiovascular system produced by spaceflight.

For example, after nine to 14 days in space, research suggests that aerobic capacity (VO2peak) is lowered by 20% to 25%. However, the patterns are intriguing. After the initial reduction in aerobic capacity, the body appears to compensate and the numbers begin to improve – though they never return to pre-trip levels – during longer periods in space – say, five to six months – after the initial reduction in aerobic capacity, the body appears to compensate and the numbers begin to improve – though they never return to pre-trip levels.

4) You will lose bone mass

On Earth, the forces of gravity and mechanical loading are required to keep our bones in good shape. This does not occur in space. 

what happens to your body in space?Photo via Cancer Care of Western New York

Bone is constantly remodelling, and two types of cells are involved: osteoblasts (which build and maintain the bone matrix) and osteoclasts (which break down the bone matrix) (these absorb bone matrix). However, during spaceflight, the equilibrium of these two processes is disrupted, resulting in decreased bone mineral density. 

According to studies, after 16 to 28 weeks in space, a 3.5 percent loss of bone occurs, with 97 percent of the loss occurring in weight-bearing bones like the pelvis and legs.

5) Your immune system is weakened

The body's immunological system, which defends against sickness, is also harmed. 

what happens to your body in space?Photo via New York Times

Radiation, microgravity, stress, solitude, and changes in the circadian rhythm, the 24-hour cycle of sleep and wakefulness that we follow on Earth, are all factors that contribute to this. Additionally, astronauts will come into contact with microbes from themselves, other crew members, their food, and their environment while in space, all of which can alter their immune response, potentially resulting in difficult situations and increasing the risk of infections among the crew as well as contamination of extraterrestrial sites.

By: Aishah Akashah Ahadiat

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