Sending astronauts into space is a complicated affair. It’s not just about mastering the mechanics to launch a manned rocket. It’s also about ensuring the human beings aboard stay healthy before, during, and after a mission that will push their bodies to new limits.
During her July 27 plenary session at ADLM 2026, Kathleen McMonigal, MD, FCAP, director of the NASA Johnson Space Center Clinical Laboratory, will delve into the fascinating complexities of monitoring and managing astronauts’ health.
McMonigal is the NASA physician lead for the development of medical standards for the Artemis program and for the medical standards working group for the International Space Station. She has been the clinical laboratory director at the Johnson Space Center since 2000.
She served an initial stint as a pathology consultant to NASA. “[Then,] there was a new division chief that came in and asked, ‘What am I doing with a board-certified pathologist when I could use her in the lab?’” McMonigal said. She started with the agency as a diving medical officer, helping astronauts train for weightless environments in a large pool.
Long before the recent Artemis II flight sent humans the farthest distance they’ve ever been from Earth, McMonigal and her team were attending to astronauts living at the International Space Station.
At the plenary, she will speak about the unique stressors astronauts face in space, like cosmic radiation, prolonged isolation, circadian disruption, altered microbiomes, and weakened immune systems. She will also explain how she and her team are gearing up astronauts to return to the surface of the moon. Her current focus is on conditions that arise due to zero- and micro-gravity changes. Without Earth’s gravity pulling fluids down in the body, the liquids pool in the head and chest.
Such a shift can trigger minor issues like sinus congestion as well as more serious conditions such as venous thromboembolism (VTE). “Because fluid has moved up, and there isn’t the gravitational pull to pull it back down and keep it circulating, we’re more likely to get venous stasis in our blood vessels, including internal jugular veins in the brain,” McMonigal said. She and her team conduct blood tests to assess astronauts’ risk for VTE.
Astronauts’ eyes can also change shape because of the additional pressure to the head. Because this doesn’t happen to every astronaut, McMonigal and her NASA colleagues are trying to figure out what might predispose someone to it.
On her current wish list is a device like a tricorder from the Star Trek universe: a compact, handheld sensor that can do a quick analysis of someone in distress. While technology isn’t that far advanced yet, McMonigal hopes to be able to send astronauts into space with a device that can test for basics like complete blood count levels in their blood. She envisions a tool that would use different cartridges that allow for different types of tests, she said, “to be able to look and see that, if somebody’s been injured, do I have to worry about them, and do I have to worry about bringing somebody home?” The device would need to operate in zero gravity and be durable enough to withstand the violent shaking that happens during blast off.
McMonigal will share with ADLM 2026 attendees the details of the rigorous screening NASA currently conducts on astronauts before flight.
“[This testing] makes sure they don’t have anything that we could possibly fix before they go into space, whether for six months on an International Space Station mission or a lunar mission,” she said. “If we can identify what would be a problem ahead of time, we can fix them and then they could fly, because we don’t have instrumentation that could make it easy for when they’re in space.”
Jen A. Miller is a freelance journalist who lives in Audubon, New Jersey. +Bluesky: @byjenamiller.bsky.social.
