WASHINGTON: When pediatric cancer survivor Hayley Arceneaux and a trio of crewmates spent three days in space in 2021 as part of SpaceX’s Inspiration4 mission, they made history not only as the first all-civilian team to orbit Earth. They also provided the most in-depth data on record regarding the effects of space travel on the human body.

New research based on this data details changes in the brain, heart, muscles, kidneys and skin, immune regulation and stress levels and a breakdown in the activity of subcellular structures called mitochondria amid the microgravity environment, increased radiation and other factors in space.

More than 95 per cent of the biomarkers tracked in the research returned to preflight levels in the months after the crew returned to Earth, though some abnormalities including in the mitochondria persisted, the researchers said. But the data indicated that spaceflights — at least short-duration ones — do not pose significant health risks, they concluded.

“We did not see anything that was worrisome, thankfully,” said Chris Mason, a professor of physiology and biophysics at Weill Cornell Medicine in New York who helped lead the research, with studies published on Tuesday in Nature and other journals. “This bodes well for other groups of civilians planning to live and work in space.” “We did see some evidence of brain-associated proteins in the blood after the mission, which we had also seen once before in the Twins Study (a 2019 study based on retired Nasa astronauts and twins Scott and Mark Kelly), and we think is evidence of brain stress during the mission,” Mason added.

Mason said this might be explained by findings in experimental mice flown to space that experienced disruptions in the blood-brain barrier, a layer of cells protecting the brain. Cognitive function in the Inspiration4 crew, as measured by the University of Pennsylvania’s Mathias Basner, was not affected, Mason noted.

Arceneaux, a physician assistant at St. Jude Children’s Research Hospital in Memphis and the mission’s medical officer, and her crewmates — aerospace data engineer Chris Sembroski, geoscientist Sian Proctor and billionaire entrepreneur Jared Isaacman — were monitored before, during and after the flight. They underwent extensive testing and provided blood, saliva and other samples — including skin biopsies that left a lasting mark.

“I love my space scar,” said Arceneaux, who was 29 at the time and became the youngest American to orbit Earth, adding that the crew “really wanted to make a scientific impact.” The research encompassed data from the two women and two men from Inspiration4 as well as information from 64 astronauts who participated in longer stints aboard the International Space Station (ISS) and other missions. Inspiration4 flew at roughly 370 miles (590 km) above Earth, higher than the ISS, meaning the crew faced higher radiation levels.

“So far, females seem to return to baseline (preflight status) faster than males, but our numbers are too small for this to be definitive,” Mason said.

The onset of a “second Space Age” characterised by commercial missions has heightened the urgency to understand health risks, according to bioinformatician Afshin Beheshti of the Blue Marble Space Institute of Science in Seattle, another leader of the research.

Published in Dawn, June 12th, 2024