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Each of the four crew members aboard SpaceX’s Polaris Dawn mission reported different physical sensations during their history-making trip, which sent the private astronauts into a higher Earth orbit than any human has ventured in decades.
“My vision started to deteriorate the first few days,” Scott “Kidd” Poteet, a former US Air Force pilot, told CNN’s Dr. Sanjay Gupta in a recent interview.
His crewmate Anna Menon, a SpaceX engineer who was the Polaris Dawn mission’s doctor, said she suffered from space adjustment syndrome. It’s a phenomenon that affects about 60% to 80% of people traveling in orbit, although astronauts rarely openly discuss the disorder.
“It can be a whole spectrum of experiences from dizziness, nausea, all the way to vomiting,” Menon said. “I really experienced the whole spectrum.”
Traveling to space – with its jarring g-forces and disorienting weightlessness – can have a variety of effects on the human body, from the uncomfortable to the downright dangerous.
NASA has long known about and studied these disorders, as the agency’s astronauts have reported such symptoms for decades.
But the Polaris Dawn mission — a five-day journey into orbit conducted by the private sector instead of NASA — sought to take this research further, hoping to unravel some of the most vexing aspects of space travel.
During the mission, the crew performed a series of health-focused experiments, including wearing special contact lenses that measured the pressure in their eyes and undergoing MRI scans to track changes in their brain anatomy.
The Polaris Dawn team pursued those answers because the mission aims to pave the way for more humans to venture into space, noted Jared Isaacman, the billionaire founder of payments technology company Shift4. Isaacman helped finance and was in charge of the unprecedented mission.
“About 600 people have been in orbit in the last 60 years — more than half have developed spatial adaptation syndrome,” Isaacman said. “And you’re talking about (mostly government astronauts) — some of the most screened people. … It just underscores the importance of why we have to address this if we’re going to put hundreds or thousands of people in space one day.”
SpaceX’s fundamental goal is to fly the first humans to Mars and eventually establish a settlement there.
“If you think thousands of a future where there are people living in space, and they eventually – after nine months of travel – you get to the surface of Mars, and a large percentage (of people) have vision changes that make them out able to do that. their work, unable to read their procedures — that’s a big problem,” Menon said of why SpaceX hopes to find answers to urgent medical conditions in space.
During the September mission, the Polaris Dawn crew completed the first commercial spacewalk and ventured into the lower band of Earth’s Van Allen radiation belts, which are regions within Earth’s magnetic field where pools of radiation from the Sun are trapped.
Initial reports from the Polaris Dawn crew did not necessarily reveal any specific health effects from radiation exposure, although Isaacman said he saw “sparks or lights” when he closed his eyes, as did other NASA astronauts who have ventured through high-radiation environments have reported. This phenomenon is not yet well understood.
However, Poteet said his vision was noticeably less sharp during the first few days in space, which may point to a condition called spaceflight-associated neuro-ocular syndrome, or WITHOUT.
NASA estimates that as many as 70% of astronauts experience this condition, which can be caused by changing body fluids, resulting in pressure changes in the eyes.
Poteet’s vision changes may have shown up in the data collected by the special contact lenses worn by the crew, which they nicknamed the “cyborg experiment.” The contacts were designed to collect data on interocular pressure during their mission, Menon said.
“This is new because you get long-term data. And then you can really better understand how that transition happens over time and especially the early time in space,” she said. “We’re really interested in seeing what the researchers turn back with when they have a chance to look through all that data.”
Dr. Allison Hayman, a researcher and associate professor at the University of Colorado Boulder who led the cyborg experiment, said Friday that scientists had not yet received preliminary data from the mission.
In total, the Polaris Dawn team performed 36 experiments on behalf of 31 partner institutions, including universities and NASA.
Back on Earth, Poteet reported that his vision quickly returned to normal.
And while he had some unfortunate vision loss during the trip, Poteet said he was happy to report that he didn’t experience any of the nausea typically associated with spatial adjustment syndrome, which he called “pretty ironic.”
“People assume there is a link between motion sickness (on Earth) and spatial adjustment syndrome,” he said. “I tend to get motion sickness in the back of an Uber. … But I didn’t actually experience these symptoms (in space).”
Menon noted that she was not so lucky.
“It really just gave me a tremendous appreciation of how it can affect your ability to work and get things done, especially in the early days of adjustment,” Menon said.
Before takeoff, Isaacman — the only crew member with previous space travel experience — told CNN that drugs given to treat space adjustment syndrome symptoms can put people to sleep for eight hours or so. (He led a previous self-funded trip to orbit called Inspiration4 in 2021.)
Sarah Gillis, a senior SpaceX operations engineer who was a mission specialist aboard Polaris Dawn, also noted that crew members had their blood drawn before and after the mission to evaluate how their bodies processed drugs — such as acetaminophen (or Tylenol) — in circulation versus on the ground.
Another experiment the Polaris Dawn crew underwent to understand disorders in space involved a series of MRI scans just before takeoff and immediately after returning to Earth.
The crew even had a portable imaging machine right outside their quarantine facility, Isaacman said. This allowed the team to collect data even faster than NASA has collected such scans on astronauts after returning from space, Menon said.
“Even these MRI results show changes in brain anatomy,” she said.
The changes have included brains moving upward in the astronauts’ skulls, according to Dr. Donna Roberts, deputy chief scientist at the ISS National Laboratory, who has spent years researching the effects of spaceflight on brain structure. Roberts noted Thursday that initial reviews of the MRI data “did not show any clinically relevant findings.”
Spaceflight can also enlarge fluid-filled cavities in the center of the brain, called ventricles, Roberts added.
“We don’t fully understand why this happens,” she said.
Gillis, whose job at SpaceX includes training NASA astronauts on their way to orbit, said in a pre-departure CNN interview that “human spaceflight is not going to be glamorous all the time” because of the discomfort microgravity can cause on the human body .
When she returned, Gillis reflected on the effects. “It’s been so incredibly fascinating to actually go through all these changes to see how your body reacts and how the fluid shift affects you and how all your organs change inside you,” she said.
“We don’t thrive without atmosphere, without oxygen,” Gillis added. “I think that really just underscores the importance to me of the research that we’re doing, the data that we’re collecting.”