The new era of human spaceflight is fraught with medical and ethical questions

Medical researchers have studied how spaceflight affects the health of astronauts since the dawn of the Space Age (SN: 23.6.62). Known problems include bone loss, increased risk of cancer, impaired vision, weakened immune system and mental health issues (SN: 6/30/22, 7/15/20, 3/8/24). However, what is happening at a molecular level has not always been clear.

A new project known as the Space Omics and Medical Atlas, or SOMA, is poised to help answer such questions. A set of 26 cards appeared on June 11 in various Nature journals, representing the largest database of aerospace medicine and space biology published to date.

SOMA is responding, in part, to a big change happening in human spaceflight — the rise of commercial crewed missions like Axiom, Polaris Dawn and SpaceX’s Inspiration4. The project’s data includes clinical information from these missions, as well as those from NASA and JAXA, the Japanese Space Agency. While professional astronauts employed by government agencies must undergo rigorous health screenings, no such similar regulations apply to private space tourists, leaving sharp medical, legal and ethical questions unanswered.

Space lengthens human telomeres

Perhaps NASA’s best-known long-term biomedical study involved identical twins Scott and Mark Kelly (SN: 4/11/19). The researchers looked at how Scott’s 340-day stay on the International Space Station affected his physiology, gene expression, immune system and mental reasoning compared to Mark, who stayed on the ground.

A fascinating finding from the study was that Scott Kelly’s telomeres got longer. Telomeres are short stretches of repetitive nucleic acids found at the end of DNA that act like a shoelace cap, protecting the DNA strand. As cells divide, telomeres become shorter, a process thought to be associated with aging. But that didn’t mean Kelly was getting any younger while in space. In fact, he was potentially at risk of cancer.

Some cancers “protect telomere length or cause telomere lengthening,” says Eliah Overbey, professor of bioastronautics at the University of Texas at Austin. “That’s part of the reason why these cancers are tricky, because they’re going to divide, divide, divide, but their telomeres aren’t shortening.” Fortunately for Scott Kelly, once he returned to Earth, his telomeres shrunk back to their pre-flight size.

But the experiment was limited by its small sample size.

“NASA did not repeat these types of studies on their future crews,” Overbey says. “They could routinely perform this if they wanted to, but they’re not pursuing this line of research very aggressively.”

Telomere length, along with other molecular changes, including those related to the immune response, DNA repair and stress, are clues that Overbey and colleagues have collected with SOMA. And the data shows that short-term spacewalks, as short as three days, by commercial crews like Inspiration4 may have genetic effects not so different from those of long-duration missions.

For the Inspiration4 crew, their telomeres lengthened during their short adventure and then returned to normal on land. “Even though they were only there for three days, we were actually still able to see what was a pretty dramatic effect,” Overbey says.

Many other molecular changes followed similar patterns as the Twins Study, shifting during spaceflight for both short- and long-duration flights and then returning largely to baseline once back on Earth, the SOMA data suggest. .

What this means for the health of astronauts is not yet entirely clear, especially when projected into the much longer timescales that might involve a mission to Mars or a stay on a lunar base. Despite an increase in the number of people going into space, sample sizes remain small, given that each of the new private missions has had a crew of four. Still, Overbey and her colleagues aim for SOMA to become a hub for data on commercial and government missions that can help answer pressing health questions.

“I see a lot of these datasets as hypothesis-generating machines,” she says.

Limited regulations raise ethical concerns

But the growing number of private individuals heading into space involves a host of ethical problems. Professional astronauts are constantly checked by specially trained doctors in order to continue going into orbit while, in general, the most important thing a commercial spaceflight participant needs is a lot of money. And the US government currently has no health requirements for such individuals.

To give the fledgling private space industry time to develop and gain experience without too much interference, Congress passed a moratorium on new safety regulations for commercial human spaceflight in 2004. The moratorium was originally set to it was set to expire in 2012, but has been extended several times, most recently to January 2025 with several proposed bills potentially pushing that date back by up to another six years.

That means the Federal Aviation Administration, or FAA, which oversees launch licenses, doesn’t have the ability to order private individuals to undergo a health check before climbing into a rocket chair.

“If you want to climb Mount Everest, you have to present a health certificate,” says Dana Tulodziecki, a philosopher at Purdue University in West Lafayette, Ind. “That’s more than you officially have to do to go into space.”

The FAA suggests that private astronauts consult with a physician, whom they recommend is trained in spaceflight issues, before flying. But no one checks to make sure that happens. And even if a doctor stopped a person from checking in on a commercial flight, what’s to stop that person from just finding another doctor to fix it?

“These are obviously really complicated issues,” Tulodziecki says, noting that lawmakers need to start figuring out what to consider about who should be allowed to fly private missions long before the moratorium on regulations expires. .

“There are a lot of space ethics efforts that think about really big issues; political systems on other planets and what not,” she says. “But that’s really far in the future, isn’t it? This is already here, already happening. So it’s really urgent.”