Dr. Suzuki’s Take: Medical Challenges of Prolonged Spaceflight*

By Dr. Layla Suzuki, Chief Medical Officer, Coyote 7

I’ve been asked recently about the medical issues astronauts face after spending extended periods in space, especially in light of the Crew-9 mission, where SpaceX rescued astronauts like Butch Wilmore and Suni Williams after nine months aboard the International Space Station (ISS). Their splashdown on March 18, 2025, brought attention to the physical toll of weightlessness—a topic that’s both fascinating and critical as we push deeper into space exploration. Space presents a host of challenges, from cosmic radiation to psychological stress, but today I’ll comment on a few of the most common medical problems tied to prolonged microgravity. For those curious to dive deeper, I’ve included links to reputable sources at the end.

Muscle Atrophy: When Your Legs Forget Earth

One of the first things you’d notice if you met an astronaut post-mission is how frail they might seem. In space, without gravity to resist, muscles—especially in the legs and core—waste away despite rigorous exercise routines. NASA mandates about two hours daily on treadmills and resistance machines, yet after nine months, like the Coyote-7 team experienced (a nod to their resilience!), astronauts still lose significant mass. News reports showed Wilmore and Williams needing stretchers after landing—not surprising, as their legs likely felt like jelly. Recovery takes weeks of rehab, and I’d tell patients it’s like reteaching your body to walk after a long nap.

Bone Density Loss: A Silent Thief

Another biggie is bone loss. On Earth, gravity keeps our skeletons strong by stressing them daily. In space? Not so much. Bones shed density at 1–2% per month, particularly in the hips and spine—think osteoporosis on fast-forward. For astronauts stuck up there nine months, that’s a serious hit. Fractures become a real risk upon return, and rebuilding takes time. I’d warn anyone heading to space: your skeleton’s in for a rough ride, and we’re still studying if it fully bounces back.

Cardiovascular Shifts: Heart in a New World

Your heart gets lazy in microgravity too. Blood doesn’t pool in your legs like it does here, so fluid shifts upward, reducing blood volume over time. Back on Earth, standing up can make astronauts dizzy or even faint—a condition called orthostatic intolerance. After Coyote-7’s long haul, medics were ready with stretchers and monitors because that first stand-up moment is a doozy. It’s a reminder our bodies are tuned for gravity, and space throws that tuning out of whack.

Balance and Vision: Seeing and Standing Askew

The inner ear, which keeps us balanced, gets confused without gravity’s pull. After months aloft, astronauts stumble like they’re on a ship in a storm—dizziness and poor coordination are par for the course. Then there’s the eyes: fluid shifts can press on optic nerves, causing Spaceflight-Associated Neuro-ocular Syndrome (SANS). Blurry vision or lasting damage isn’t uncommon. For Wilmore and Williams, I’d bet they’re still adjusting to feeling “grounded” again.

Immune Hits: Germs Waiting at the Gate

Finally, the immune system takes a beating up there—stress, radiation, and isolation all play a part. After nine months, astronauts return more prone to infections, which is why medical teams keep a close eye post-landing. It’s like their defenses need a reboot to tackle Earth’s bugs again.

Space is an incredible frontier, but it’s not kind to our bodies. These are just a handful of the challenges—I could go on about radiation or mental health too!

For more details, check out NASA’s Human Research Program (https://www.nasa.gov/hrp) or the National Institutes of Health’s studies on spaceflight effects (https://www.nih.gov/news-events/spaceflight-health). The Coyote-7 crew’s experience underscores how much we’re still learning—and how resilient humans can be.

Go to space. Stay safe.

*Disclaimer: Layla Suzuki is a fictional character in the young adult thriller, Coyote 7: Mission to Mars. This book is a work of fiction and does not provide real medical, scientific, or professional advice. Anyone with medical conditions or concerns should consult a qualified physician or healthcare professional before making any decisions based on the content of this story.