Image source, NASA/Getty Images
The current record of a single space for American astronauts is 371 days, but long -term rail flight will change the astronaut's body in some surprising ways, giving them muscles, brain, and even intestinal bacteria bring them.Come change.
After a few handshake and short photos, the National Aeronautics and Space Agency (NASA) astronaut Frank Rubio waved farewell to the International Space Station.This American football field -sized module and solar panel collection have been his home in the past 371 days.He left the International Space Station and returned to the earth, marking the end of the longest single space flight of Americans so far.
In March 2023, the cooling agent leaked by the spacecraft with the crew members of the crew, which caused the orbit time to extend, which caused it to surpass the 355 -day record of the Americans's previous 355 consecutive days in space.In the space in space, the Rubio had a total of 5963 laps around the earth with a schedule of 157.4 million miles (253.3 million kilometers).
Even so, he is still two months behind the longest space flight records in human history -in the mid -1990s, Russian astronauts Valeri Polyakov (Valeri Polyakov) was in the "Peace".I stayed on the space station for 437 days.
The "Alliance MS-23" spacecraft landed safely in a dust near the Town of the Herzkazan Town of the Kazakhstan, and Larie was lifted off the spacecraft with a bright smile.Because he spent such a long time in the low -gravity environment of the International Space Station, his body had some damage, so he had to be carried out of the space cabin by the recycling team.
However, his extended space journey will provide valuable insights for human beings to respond to long -term space flight and how to deal with the problems it may bring.He is the first astronaut to participate in the study to the human body when exercise will have a limited fitness equipment.
As humans explore the solar system with more deeper vision, this information will be proven to be crucial.For example, according to the current plan, the journey returning to Mars is expected to take about 1100 days (more than three years).Astronauts will take a lot of spaceships than international space stations, which means that smaller light sports equipment is required.
However, what impact does space flight affect the human body without talking about fitness issues?
muscle and bones
In space, without the continuous tension of our limbs, muscle and bone mass will decrease rapidly.The most affected are the muscles that help us maintain the back, neck, calf, and quadriceps of the four -headed muscle -in a micro -gravity state, they no longer need to work hard as before, so they start to shrink.
In just two weeks, muscle quality will drop by 20%, and in the long -term task of three to six months, muscle quality will decrease by 30%.
Image source, NASA/Getty Images
Similarly, because the astronaut's bones are not as large as such a large mechanical load as they are under the action of the earth's gravity, their bones will begin to decarcal and become fragile.
Astroniste spent 1 to 2%of bone volume every month in space, and lost up to 10%in 6 months (on the earth, the bone loss rate of elderly men and women is0.5%to 1%per year).This increases the risk of their fractures and extend the time required for fracture healing.After returning to Earth, their bone volume may take up to four years to return to normal.
To solve this problem, it has to conduct 2.5 hours of exercise and high -intensity training every day in the railstomers.These include a series of squats, hard lifts, rowing and bench press training using resistance sports devices installed in the "gym" installed in the International Space Station, as well as regular exercise on treadmills and fitness bicycles.They also take dietary supplements to maintain bone health as much as possible.
However, a recent study emphasized that even such exercise methods are not enough to prevent muscle function and volume loss.This study recommends testing whether higher -load resistance exercise and high -intensity intermittent training will help offset this muscle loss.
Due to the lack of gravity of pulling down the body, astronauts will find themselves a little taller during the stay at the international space station because their spine will extend slightly.This may lead to some problems, such as pain on the back when space, and the disconnected intervertebral disc.
Before returning to the earth, Rubio himself said at a briefing at the International Space Station that his spine was growing and said it could help him avoid common neck damage.When the spacecraft hit the ground, if the astronaut tries to raise his head from the seat to see what happens, this injury may be suffered.
"I think my spine has stretched to a sufficient extent. I seem to be stuck in the seat pad, so I should not move too much," he said.
weight loss
Although weight is not significant in orbit -a micro -gravity environment means that anything that has not been tied to can float freely in the international space station, including the human body -but maintaining healthy weight on the track is one item is one item is a item is one item is one item.challenge.
Although the National Aeronautics Aviation Administration strives to ensure that astronauts eat various nutritional foods, including some salad leaves recently planted on the space station, this will still affect the astronaut's body.
NASA astronaut, Scott Kelly, participated in the most extensive research on long -term space flight.He stayed on the International Space Station for 340 days, while his twin brothers remained on the earth.During the rail, his weight decreased by 7%.
"Researchers checked him after returning from Scott Kelly to the International Space Station, and found that the bacteria and fungi in his intestine changed a lot compared to entering space."
Vision
On the earth, gravity will force the blood in our body to flow down, and the heart will push the blood back up.However, in space, this process will become chaotic (although the body will adapt to a certain extent), and blood will accumulate more than normal in the head.Some of these blood will accumulate around the rear of the eyeball and the optic nerve, leading to edema.
This will lead to vision changes, such as decreased sharpness and structural changes in the eyes itself.These changes may begin to appear two weeks later.Over time, risks will increase.Some vision changes will be reversed within one year after the astronauts return to the earth, but some may be permanent.
exposed to the galaxy cosmic rays and high -energy sun particles can also cause other eye diseases.The atmosphere of the earth helps us to avoid these damage, but once it enters the track of the International Space Station, this protection will disappear.
Although spacecraft can carry shielding devices to help block excess radiation, astronauts on the International Space Station report that when cosmic rays and solar particles hit their retina and optic nerve, their eyes will see flash.
nerve change
Researchers have found that after staying on the International Space Station for a long time, Kelly's cognitive ability has not changed much, and it is relatively the same as his brother's cognitive ability on the ground.However, the researchers did notice that the speed and accuracy of Kelly's cognitive ability did decrease within about six months after his landing.There is a different way of lifestyle.
In 2014, stay at an international space station 169Studies by Sky Russian astronauts show that in the orbit, the human brain itself seems to have changed.Studies have found that the neurological connection levels related to motion function in the brain have changed, and the vestibular leather has also changed. The vestibular leather plays an important role in direction, balance, and perception of our own movements.
Considering the particularity of space loss, this may not be surprising; astronauts usually must learn how to move them effectively without gravity, fix them on any object, and adapt to a world without up and down.
Recent research has caused people to worry about other changes in the brain structure during the long -term space mission during the space mission.The brain is called the cavity of the right outer side of the brain and the third brain chamber (responsible for storing the cerebral spine, providing nutrition and processing waste for the brain), and it takes up to three years to reduce it to normal size.
Friendly bacteria
Research in recent years shows that the key to maintaining good health is the composition and diversity of living in our body and microorganisms.These microorganisms can affect our digestive food methods, affect the level of inflammation in the body, and even change our brain's working methods.
Researchers checked him after the journey of Kelly's International Space Station, and found that the bacteria and fungi in his intestine changed a lot compared with before entering space.This may not be completely surprising, because the food he eats is very different from before, and the person who gets along with him also changes (we have obtained an amazing intestinal tract and oral microorganisms from the people who are living together))EssenceHowever, it may be one of the reasons exposed to radiation and recycling water, and the changes in his physical activity.
Skin
Although five NASA astronauts have spent more than 300 days on the track, we still want to thank Kelly because he let us understand the changes in his skin on the track.
About six days after he returned from the space station, people found that his skin became more sensitive and rashes appeared.Researchers speculated that the lack of skin irritation during the execution mission may be the cause of his skin discomfort.
gene
One of the most important discoveries brought by the extended travel of Kelly is the influence of his DNA.At the end of each DNA chain, there is a structure called telomere, which is considered to help protect our genes from damage.As the age increases, the telomeres will become shorter and shorter, but research on Kelly and other astronauts shows that space travel seems to change the length of the telomere.
"However, the most shocking thing is that we find that the length of the telomeres in space in space is obviously longer," said Susan Bailey, a professor of environment and radiation health at the State University of Colorado.
She conducted a separate study of 10 unrelated astronauts. The task time for these astronauts to participate is short, about 6 months."It is also unexpected that the telomere length of all astronauts has rapidly shortened after returning to the earth. It is particularly related to long -term health and aging trajectory."
She said that the exact cause of this situation is still studying."We have some clues, but more long -term passengers -such as the Rubio who spent a year in space -for truly describing and understanding this reaction and its potential health results."
A possible reason may be that people are exposed to complex radiation combinations in space.She said that the astronauts that have been exposed to radiation for a long time on the orbit will show signs of DNA damage.
Image source, NASA
Some changes in gene expression are also seen in Kelly, which may be related to his space journey.Gene expression is a mechanism to read DNA to produce protein in cells.Some of these changes are related to the body's response to DNA damage, bone formation, and the reaction of the immune system to the pressure.However, most of these changes returned to normal within six months after he returned to the earth.
In June 2024, a new study emphasized that there were some potential differences between the immune system of men and female astronauts to the response to space flight.This research uses the gene expression sample data obtained by the SPACEX company "Inspiration 4", which has been flying on the orbit less than three days from the autumn of 2021 to determine 18 kinds of protein related to the immune system, aging and muscle growth.change.
Study compared their genetic activities with the genetic activity of 64 astronauts who had performed the tasks before, and found that the expression of protein that played in inflammation in inflammation was changed compared to before flight.Men are often more sensitive to space flight, and their genetic activities are more disturbed. After returning to the earth, they need to restore the normal state.
Researchers have specially discovered that compared with women, the genetic activity of two protein in men is even more affected, which is the leukocyte-6 (Interleukin-6), which helps to control the level of inflammation in the body, andSend immune cells to leukocyte-8 (interleukin-8) at the infected area.Another protein fibrobinogen involved in coagulation has also been greatly affected among male astronauts.
But the researchers said that they still need to understand why women seem to be less sensitive to these special impacts of space flight, but this may be related to their reactions to stress.
You can hear the NASA astronaut Peggy Whitson in the video below describing how her life in space changes her body.Whitson stayed in space for a total of 675 days. It was the longest -stayed Americans on the track, but the World Record is currently maintained by Russian astronaut Oleg Kononenko.Cumulative stayed for 878 days.
immune system
Kelly vaccinated a series of vaccines before entering and staying in space stations before entering space, and his immune system responded normally.But Bailey's research found that the number of white blood cells in astronauts will indeed decrease, which is related to the radiation dose they receive on the orbit.
However, there are many questions about the influence of space travel on the evolution of the evolution of the earth and big head creatures that have to be answered.When researchers carefully examined the medical testing, blood samples and scanning results of Luberio, which stayed in space for 371 days, they undoubtedly wanted to know more information.
