Medical commentary: A neurologist asks: What is space really doing to the human body?

We’ve long imagined space as the final frontier — but what is it really doing to the human body?

Transcript

DR. JOSEPH SIRVEN: Recently, while watching the Artemis lunar flyby mission, I remembered something from childhood.

I was standing on a desk in my elementary school in Shreveport, Louisiana — trying to see past the taller kids, all of us crowded around a small television set — as astronauts walked on the moon.

What I felt then was awe. Pride. Possibility.

I didn’t think about risk. I assumed the astronauts had all the answers.

But today, I watch space travel through a very different lens. "Star Trek" promised we would boldly go where no one has gone before.

But what’s the price of going that far — and why should it matter?

Because what we are learning in space is already reshaping how we understand the human body here on Earth.

A recent study showed that in microgravity, the brain actually shifts upward within the skull. Fluids move, crowding key regions that control balance and vision. Astronauts can experience motion sickness in space and difficulty walking when they return — and some of these changes can last for months.

Then there are the moments we cannot yet explain.

Earlier this year, astronaut Mike Fincke suddenly lost the ability to speak for 20 minutes aboard the International Space Station. No pain. No warning. No clear cause. The event was serious enough to trigger his early evacuation back to Earth.

Universities — including researchers at UC San Diego — are now studying how microgravity can help create new medications. In space, crystals grow more perfectly, proteins behave differently, and drugs may be designed in ways not possible on Earth.

In other words, the same environment that challenges the human body may also unlock new treatments for it. As a physician with aerospace neurology expertise, I now see a frontier filled with unanswered questions.

And the humbling realization that the farther we go, the more we discover how much we still don’t understand about ourselves right here on Earth.