The Spaceflight101 Blog

I still remember walking into the flight surgeon’s office at Johnson Space Center for the first time. I’d spent a solid decade in a busy Houston hospital—infections, fractures, the long slow management of diabetes and heart failure. I figured the human body was the human body. Then someone handed me a stack of astronaut health…

My hospital colleagues often ask why an astronaut’s heart doesn’t simply give up. On Earth, we diagnose a body that knows exactly where “down” lives. In orbit, I have to unlearn that certainty. The work isn’t about exotic diseases—it’s about a perfectly healthy physiology rewiring itself when you strip away gravity’s constant tug. That’s the…

The first time I floated a central line into a patient’s subclavian vein without my feet touching the floor, I understood something no textbook had prepared me for. On Earth, the patient lies flat. The landmark—the clavicle, the sternal notch, the slight depression where the needle slips in—is predictable. In orbit, the patient drifts. I…

The first time I reviewed a treatment protocol written for the International Space Station, I felt a quiet dislocation. The document assumed its patient would be floating, unable to stand, bathed in elevated radiation, and breathing an atmosphere that had been engineered down to the last trace gas. My clinical instincts, built over years on…

In a clinic on Earth, a patient settles into a chair, gravity pressing their weight into the cushion, air thick with oxygen, a familiar horizon sitting outside the window. Now imagine the same physician floating inside a spacecraft, surrounded by the soft hum of life-support systems, where a simple blood draw demands velcro straps and…

What Space Medicine Reveals About the Body You Think You Know When I mention I work in space medicine, people tend to imagine a doctor drifting through the ISS with a stethoscope trailing behind. The truth is less cinematic but a lot weirder. The split between terrestrial and space medicine isn’t just a question of…

A patient walks into your clinic complaining of a headache. You think stress, maybe dehydration, a garden-variety migraine brewing. Now picture that same patient floating 400 kilometres up, strapped to a handrail inside the International Space Station. The same dull throb could mean cerebrospinal fluid has started pooling where it shouldn’t, intracranial pressure is quietly…

We are creatures of gravity. Every heartbeat, every neural impulse, every shift of fluid inside us evolved under a constant 1G pull. As a physician, I was taught to see the body as a system that expects this force—a silent, steady partner in every physiological equation. But step away from Earth, and that partner disappears.…

When an astronaut floats through the hatch of the International Space Station, they leave behind the familiar yank of Earth’s gravity. Their body, molded over eons by a 1g environment, stumbles into a strange new state: fluid stops pooling in the feet, the spine stretches, and the brain bobs a little differently inside its bony…

I still find it strange, even after two decades in the lab, how the most practical lessons about human cells sometimes come from the most impractical places. Right now, 400 kilometers up, inside a cramped metal station moving at 28,000 kilometers per hour, small colonies of fibroblasts and lymphocytes are bathed in cosmic rays. Meanwhile,…