They had left for eight days, they stayed nine months in space. The two American astronauts Suni Williams, 62, and Butch Wilmore, 59, are back on Earth after a stay at the International Space Station (ISS) much longer than expected due to the failures on the Boeing Starliner ship that had taken them there.
But they still can’t go home immediately. The two astronauts will first follow a physical rehabilitation program and will undergo scientific samples to collect data on the effect of microgravity (or microperator, that is, a very low gravity) in their bodies and health. Because the effects, there have been some.
• Accelerated aging
If the two astronauts were prepared and trained for this possibility, the physical consequences of a nine -month stay are not the same as a week. “The changes are proportional to the dedicated time,” he said West France Gauquelin Koch, Head of Life Sciences and Space Medicine at the National Center for Space Studies (CNES).
A stay in space, “is an accelerated aging of the human body,” Frank Lehot, a doctor specializing in aeronautics and space, also explains to the Regional newspaper. “It is a phenomenon that affects all organs.”
• Loss of muscle mass
During his stay in ESACE, the muscles of the stunica in the atrophied. “With the ungravation, we float, there is no more apparent weight. Therefore, there is no more physical effort to do. Everything becomes light. The muscles understand the message and no longer need to act,” explains Frank Lehot.
That is why astronauts must do sports every day at ISS. Or two hours of physical activity, six days a week, on a racing carpet, a bicycle attached to the ground or a hydraulic press that acts as a bodybuilding bank.
• A decrease in bone density
“Six months in Microprits (that is, a strongly reduced gravity, editor’s note), is almost 20 years of aging on Earth, in terms of bone loss,” specifies the National Center for Space Studies (CNES). The bones no longer regenerate, expand (phenomenon of osteoporosis) and become more fragile.
Astronauts complement each other with vitamin D and calcium during their stay. The investigation is also underway in the food of astronauts, adds the cynes, “as genetically modified salads that would stimulate bone growth.”
• A few more centimeters
With the impossible, the vertebral settler tends to go to bed. “There, in impossible, the phenomenon of disk compassion (located between the 33 vertebrae, the editor’s note) can no longer happen,” Details the city of space. That is not necessarily a pleasure.
“I clearly felt that my spine was lung with microgravity because my muscles were constantly contracted, I felt a lot of back pain,” recalls the Lucatan astronaut for the European Space Agency (ESA).
In space, astronauts earn a few centimeters in their size (on average 4 centimeters, Thomas Pesquet had won 2 after six months in space). Centimeters that quickly lose on their return to Earth.
• Greater exposure to radiation
The radiation levels on board the ISS are higher than on the ground, even if the radiation level remains relatively low, the Earth’s magnetic field still offers protection (the ISS is 400 kilometers from the earth). Therefore, the two astronauts were exposed more time than expected to these radiation, which can be sources of cancer. But thanks to the armor, NASA aims to limit the increase in the risk of astronaut cancer to less than 3%.
• The deteriorated immune system
“Living in space has a harmful effect on the immune system of astronauts,” says the Canadian space agency. This is explained by microgravity, the increase in exposure to radiation, the alteration of sleep cycles and increased stress. Upon their return to Earth, astronauts are more inclined to hire pathologies.
Another explanation for the deficiency of the immune system: astronaut genes are modified by their stay in space. In 2018, a study by NASA in two twin brothers showed that an extended stay in the human DNA modified in space. About 7% of Scott Kelly’s genes living 340 days aboard the ISS changed on their return.
Another study by NASA analyzed the genes of 14 astronauts who traveled to the edge of the ISS between 2015 and 2019. Almost 15,000 of its genes had been modified, reports. Geo.
• A risk of cardiovascular diseases
A study also pointed out the risk of developing cardiovascular diseases for astronauts to have performed long -term stays in space. These pathologies are also four to five times higher among astronauts who spent several months in space, reports a study published in 2016.
According to a Canadian study, after six months in space, “the astronaut arteries have lost 17% to 30% of their elasticity, compared to normal aging in the land of ten to twenty years,” says the Canadian space agency.
Another surveillance point: in space, the body of astronauts does not transform glucose normally. Astronauts develop insulin resistance, which increases the risk of developing type 2 diabetes.
• Balance losses
The operation of the internal ear is interrupted during a stay in space. So there is a good possibility that Suni Williams and Butch Wilmore experience balance in the next few days. “This happens to each astronaut, even those who go to space just for a few days,” says Emmanuel Urquieta, professor of aerospace medicine at the University of Florida Central.
• A change in vision
The impossible has an effect on eyeballs and can weaken the vision. Some astronauts must wear glasses in space when they do not need them on earth. In question: the displacement of fluids, that is, the redistribution of body fluids at the head in a microgravity environment.
This can increase calcium levels in the urine and increase the risk of renal calculations, but also increase intracranial pressure, modify the shape of the ocular globe and cause neuro-ocular syndrome associated with spatial flights that cause visual deterioration from light to light to moderate.
But the opposite can also happen. This was the case of American astronaut Jessica Meir. “When I took off, I used glasses and contact lenses, but due to the flattening of the world, I now have an” greater than average, “he tells AFP.
If your stay in space has been particularly long, its 280 days in orbit are still far from the absolute registry. In the 1990s, the Russian Cosmonaut Valeri Polyakov spent more than 400 days aboard the MIR Space Station, a year and just over a month. In 2022, American astronaut Frank Rubio remained 371 days, one year and a week, in the ISS, also due to a problem in his ship.
Source: BFM TV
