Space changes you, even on short trips off-planet.
Four people who spent three days away from Earth in September 2021 experienced physical and mental changes that included modest declines in cognitive tests, stress on the immune system and genetic changes in their cells, scientists report in a paper published Tuesday in Nature journal and many other related journals.
Almost everything that changed in the astronauts returned to normal after they fell to Earth. None of the changes appeared to be an impressive consideration for future space travelers. But the results also underscored how little medical researchers know.
Christopher Mason, a professor of genomics, physiology and biophysics at Weill Cornell Medicine in New York 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,” speaking during press conference on Monday.
The four astronauts traveled on a mission, known as Inspiration4, which was the first trip into orbit where none of the crew members were professional astronauts. Jared Isaacman, a billionaire businessman, led the expedition. Instead of bringing friends along, 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 geosciences. and Christopher Sembroski, engineer.
Inspiration4 crew members agreed to participate in medical experiments — collecting blood, urine, feces and saliva samples during their flight — and allow the data to be recorded in an online archive known as the Space Omics and Medical Atlas, or SOMA, the which is publicly available.
Although the data is anonymized, this does not provide much privacy because there were only four crew members on the Inspiration4. “You could probably tell who’s who, actually,” Dr. Proctor said in an interview.
But he added: “I just feel there’s more good than bad that comes from being able to share my information and have science 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 Space Station Station. for 340 days in 2015 and 2016, with his twin brother, Mark, a retired astronaut who is now a senator representing Arizona.
With more individuals buying space travel, the hope is that SOMA will quickly fill in more information for a wider range of people than the old white men who were selected to be astronauts in the first decades of the space age. This could lead to treatments tailored to individual astronauts to combat the effects of spaceflight.
The wealth of information also allowed scientists to compare short-term results with those that occur during longer missions.
During Mr Kelly’s year in space, age markers in his DNA known as telomeres grew longer – suggesting, paradoxically, 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 this as a sign of accelerated aging.
The telomeres of all four Inspiration4 astronauts also lengthened and then shortened, indicating that the changes are occurring in all astronauts and that they are occurring rapidly.
“A remarkable finding in many 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 single-stranded sequence of nucleic acids that translates patterns encoded in DNA into protein production. Dr Bailey said the RNA corresponding to telomeres had also changed in the astronauts and that similar changes had been seen in people who had climbed Mount Everest.
“Which is a strange connection,” he said.
This suggests that the cause of telomere lengthening and shortening is not weightlessness, but the radiation bombardment that humans experience at high altitudes and in space.
This was not the only result of space flight.
Afshin Beheshti of the Blue Marble Space Science Institute and NASA’s Ames Research Center in California pointed to molecular changes in the astronauts’ kidneys that may herald the formation of kidney stones. This wouldn’t be a problem during a three-day space trip, but could become a medical crisis during a longer mission.
“Halfway to Mars, how are you going to deal with it?” said Dr. Beheshti.
But now that the possibility is known, researchers could 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 vigilance, a measure of the ability to focus on a task and sustain attention. The astronaut stared at a box on the screen. Then a timer 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 decreased compared to when Inspiration4 astronauts performed the same test on the ground. Other tests show deficits in visual search and working memory.
“Our cognitive performance was not affected over time, but our speed response was slower,” Ms. Arcenaux said in an email. “That surprised me.”
But Dr Proctor said it might not be a real difference in their ability to perform tasks in space, just that they might be distracted. “It’s not because you can’t do better on the test,” he said. “It’s just because you look up for a minute, and there’s Earth outside the window, and you’re like, ‘Wow.'”
One of the advantages of collecting all the data is looking for connections between the changes, something that was difficult for scientists to do with older, 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 more easily targetable,” he said.
Since returning to Earth, life for some of the Inspiration4 astronauts has in many ways returned to how it was before they went into space. Ms. Arcenaux returned to 12-hour shifts as a physician assistant at St. Jude Children’s Research Hospital 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 now also a science envoy for the United States Department of State. This week, she visits 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,” he said.
Ms Arcenaux said she remembered looking at Earth from the canopy window of the SpaceX Crew Dragon spacecraft on the second day of her journey.
“I feel so connected to my fellow townspeople,” she said. “We are all one on this beautiful planet.”
As for Mr. Isaacman, he is not done with space. He and three other non-professional astronauts will embark on a mission called Polaris Dawn, which may begin next month. During this flight, again in a SpaceX Crew Dragon capsule, Mr. Isaacman and another crew member plan to attempt the first private spacewalk.
