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WASHINGTON (AP) – Nearly a year in space has put the immune system of astronaut Scott Kelly on the alert and changed the activity of some of its genes compared to its identical twin linked to Earth, announced Friday. researchers.
Scientists do not know whether the changes have been positive or negative, but the results of a unique NASA twin study raise new questions for doctors, with the space agency aiming to send people March.
Dual genetic testing has given scientists a unique opportunity to follow the details of human biology, such as how an astronaut's genes light up and go out in space differently from home. An amazing change announced Friday at a scientific conference: Kelly's immune system was hyper activated.
"It's as if the body reacted to this extraterrestrial environment a bit like a mysterious organism was in you," said Christopher Mason, a geneticist from Weill Cornell Medicine in New York, who helped lead the organization. ;study. He said that doctors are now looking for that in other astronauts.
Since the beginning of space exploration, NASA has been studying the harmful consequences on astronauts' bodies, such as bone loss requiring physical exercise. In general, they are in space about six months at a time. Kelly, who lived on the International Space Station, spent 340 days in space and set an American record.
"I never felt completely normal in space," said Kelly, now retired, in an email to The Associated Press.
But this study was a unique dive at the molecular level, with former astronaut Mark Kelly, Scott's twin, on the ground for comparison purposes. The full results have not yet been published, but the researchers presented some results Friday at a meeting of the American Association for the Progress of Science.
A number of genes related to the immune system have become hyperactive, Mason said. It is not a change of DNA, but what is called "gene expression", how genes go out and increase or decrease their protein production. Mason also spotted a tip in the bloodstream of another marker that stimulates the immune system. However, at the same time, Kelly's blood had fewer cells of another type of cell, which constituted an early defense against viruses.
It is not surprising that gene activity changes in space – it changes in response to all kinds of stress.
"You can see the body adapt to the changing environment," said Mason.
The good news is that most things returned to normal shortly after Kelly's return to Earth in March 2016. These immune-related genes, however, "seemed to have that memory or need to be almost in a state of alert "even six months later, Mason told me.
"Overall, it's encouraging," said Craig Kundrot, who leads NASA's research on life in space and science. "There are no major new warning signs. We are seeing changes that we did not necessarily anticipate, "but we do not know if these changes matter.
NASA already knew that it was possible to extend its stay on Earth for four years, while Russia had four Russians in space, said Kundrot, adding: "We are also aiming for more than anything else. is possible. We want our astronauts to do more than survive. "
In the end, the twin study provides NASA with a catalog of points to watch for future missions to determine if other astronauts are responding in the same way. Future mission astronauts will be able to do some of these tests in space instead of freezing samples for scientists returning home, Mason said.
Immune problems seem familiar to Dr. Jerry Linenger, an American astronaut who spent more than four months on the Russian space station Mir. He said that he was never sick in orbit, but once back on Earth, "I was probably sicker than in my life.
The astronauts launch into orbit with their own germs and are exposed to the germs of their teammates. After a week without anything new in the "very barren environment" of a space station, "your immune system is really not challenged," said Linenger.
A human mission on Mars, which NASA hopes to launch in the 2030s, will last 30 months, including time on the surface, Kundrot said.
Radiation is a major concern. The mission would expose astronauts to levels of cosmic galactic radiation that exceed NASA's safety standards. It's "just a little over," he said.
On Earth and even on the space station, the Earth's magnetic field protects astronauts from a lot of radiation. There would be no such armor on the way to Mars, but tunnels or earth-covered habitats could help a bit on Mars, Kundrot said.
Kelly, who turns 55 next week, has announced that he will go to Mars. He said that such a long trip "would not be worse than what I experienced." Maybe better. I think the big physical challenge, radiation aside, will be a mission where you will stay in space for years. "
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The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.
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