Space changes you, even during short trips off-planet.
Four people who spent three days outside Earth in September 2021 experienced physical and mental changes that included modest declines in cognitive tests, heightened immune systems and genetic changes within their cells, scientists report in a suite of papers published Tuesday in the journal Nature and some. other related journals.
Almost everything that changed in the astronauts returned to normal after they splashed back to Earth. None of the changes seemed to be of great concern to future space travelers. But the results also highlighted how little medical researchers know.
Christopher Mason, a professor of genomics, physiology and biophysics at Weill Cornell Medicine in New York City and one of the leaders of the research, called the collection of documents and data “the most in-depth examination we’ve ever had of a crew.”, as he said during a press conference on Monday.
The four astronauts traveled on a mission, known as Inspiration4, which was the first trip to orbit where none of the crew members were professional astronauts. Jared Isaacman, a billionaire entrepreneur, led the mission. Instead of bringing friends with him, he recruited three travelers who represented a broader cross-section of society: Hayley Arceneaux, a physician’s assistant who survived childhood cancer; Sian Proctor, a community college professor who teaches geoscience; and Christopher Sembroski, an engineer.
Inspiration4 crew members agreed to participate in medical experiments — collecting blood, urine, feces and saliva samples during their flight — and allowing the data to be cataloged in an online archive known as Space Omics and Medical Atlas, or SOMA, which is available to the public.
Although the data is anonymized, this does not provide much privacy because there were only four crew members on the Inspiration4. “You can probably figure out who’s who, actually,” said Dr. Proctor in an interview.
But she added, “I just feel there’s more good than harm that comes from me being able to share my information and for science to progress and learn.”
SOMA also includes data from other people who have flown on private space missions, as well as Japanese astronauts who have flown on the International Space Station, and a study that compared the health of Scott Kelly, a NASA astronaut who lived on the International Station of Space. for 340 days in 2015 and 2016, with his twin brother, Mark, a retired astronaut who is now a senator representing Arizona.
With more private citizens buying trips to space, the hope is that SOMA will soon provide more information to a wider range of people than the old white men who were selected to be astronauts in the early decades of the space age. . This could lead to treatments tailored to individual astronauts to combat the effects of spaceflight.
The wealth of information has also allowed scientists to compare short-term effects with what happens during longer missions.
During Mr Kelly’s year in space, age markers in his DNA known as telomeres grew longer – suggesting, surprisingly, that he had become biologically younger. But the telomeres mostly returned to their previous size after he returned to Earth, although some ended up even shorter than before he left. Scientists interpreted it as a sign of accelerated aging.
The telomeres of all four Inspiration4 astronauts also lengthened and then shortened, indicating that the changes occur in all astronauts and that they occur quickly.
“A remarkable discovery in a number of ways,” said Susan Bailey, a professor of radiation cancer biology and oncology at Colorado State University, who led the telomere research.
Cells use RNA, a string of single-stranded nucleic acids that translates the blueprints encoded in DNA into protein production. Dr. Bailey said the RNA corresponding to telomeres had also changed in astronauts and that similar changes had been observed in people climbing Mount Everest.
“It’s a strange connection,” she said.
This suggests that the cause of telomere growth and shrinkage is not weightlessness, but the radiation bombardment that humans experience at high altitudes and in space.
This was not the only effect of spaceflight.
Afshin Beheshti of the Blue Marble Space Science Institute and NASA’s Ames Research Center in California pointed to molecular changes in astronauts’ kidneys that could represent kidney stone formation. This wouldn’t be a problem during a three-day spacewalk, but could turn into a medical crisis during a longer mission.
“Halfway to Mars, how are you going to handle it?” said Dr. Beheshti.
But now that the possibility is known, researchers can study how to prevent kidney stones or develop better methods to treat them.
Astronauts took several tests on iPads to measure their cognitive performance in space. One test assessed what is known as psychomotor alertness, a measure of the ability to focus on a task and sustain attention. The astronaut looked at a box on the screen. A stopwatch then suddenly appeared inside the box, counting the time until a button was pressed.
If the response was too slow, longer than 355 milliseconds, this was considered a lack of attention. On average, performance in space dropped compared to when Inspiration4 astronauts did the same test on Earth. Other tests show deficits in visual search and working memory.
“Our recognition performance was intact in space, but our velocity response was slower,” said Ms. Arcenaux in an email. “That surprised me.”
But Dr. Proctor said this may not have been a real difference in their ability to perform tasks in space, just that they may be confused. “It’s not because you don’t have the ability to take the test better,” she said. “It’s just because you look up for a minute, and the Earth is outside the window, and you’re like, ‘Wow.'”
One of the advantages of collecting all the data is looking for connections between changes, something that was difficult for scientists to do with earlier, narrower data sets. “When you look at it as a whole, you start to see the pieces of the puzzle together,” said Dr. Beheshti.
That could indicate a common cause, “and then countermeasures are easily more targeted,” he said.
Since returning to Earth, life for some of the Inspiration4 astronauts has in many ways returned to the way it was before they went into space. Ms. Arcenaux is back on 12-hour shifts as a physician assistant at St. Mary’s Children’s Research Hospital. Jews in Memphis. Dr. Proctor is still a community college professor. Mr. Sembroski, who lives near Seattle, now works as an engineer at Blue Origin, the rocket company owned by Jeff Bezos.
But Dr. Proctor is also now a science envoy for the United States Department of State. This week, she is visiting Peru and Chile, sharing her experiences in schools and universities. “Now I also have this kind of global platform where I can go and do things like inspire and help prepare the next generation,” she said.
Ms Arcenaux said she remembered looking at Earth from the dome window of the SpaceX Crew Dragon spacecraft on the second day of its journey.
“I feel so connected to my fellow earthlings,” she said. “We are all one on this beautiful planet.”
As for Mr. Isaacman, he’s not done with space. He and three other non-professional astronauts will embark on a mission called Polaris Dawn, which could launch next month. During that flight, back in a SpaceX Crew Dragon capsule, Mr. Isaacman and another crew member are planning to take the first private spacewalk.