What If An Astronaut Gets Sick In Space? This Is NASA's Plan

Last Updated:June 26, 2025, 14:56 IST

Though not every crew has a certified doctor onboard, each mission designates one astronaut as the Crew Medical Officer (CMO), typically someone who has undergone medical training

In the ISS's 20-plus years of operation, no astronaut has ever had to be evacuated due to a medical emergency. (AI-Generated Image)

By June 2025, more than 280 astronauts from over 20 countries have set foot aboard the International Space Station (ISS), spending weeks and months orbiting Earth in microgravity. While the focus of these missions often lies in scientific experiments and global collaboration, the reality is that astronauts are human, and humans get sick. But what happens when illness strikes hundreds of kilometres above the Earth’s surface?

There are no traditional hospitals in space, no emergency rooms or surgeons on standby. Yet space agencies have meticulously prepared for the possibility of medical crises. From minor ailments like toothaches and skin rashes to potentially life-threatening conditions, astronauts are trained to respond, and the ISS is equipped to assist.

A Doctor In Orbit?

Though not every crew has a certified doctor onboard, each mission designates one astronaut as the Crew Medical Officer (CMO), typically someone who has undergone extensive medical training, even if they’re not a physician. They’re supported by a well-stocked medical kit and guided, when needed, by ground-based experts.

The ISS medical kit includes:

• Painkillers, antibiotics, sedatives, and allergy medications
• Tools for wound dressing and suturing
• A portable ultrasound device
• Automated External Defibrillators (AEDs)
• Equipment for administering CPR in zero gravity

“Providing effective CPR in space requires anchoring oneself using foot restraints or special equipment, because without gravity, chest compressions are nearly impossible in the traditional sense," NASA has explained in previous training manuals.

When Ground Support Becomes Life Support

Should a serious medical condition arise, astronauts don’t face it alone. Real-time video and audio communication allows doctors at NASA’s Mission Control in Houston to provide live telemedical assistance. Using biometric data transmitted from the ISS and step-by-step guidance, they can instruct the onboard crew on procedures.

But when a situation becomes critical, beyond the capability of onboard treatment, the contingency plan kicks in: emergency evacuation.

The ISS always has at least one Soyuz or SpaceX Dragon capsule docked, capable of performing what’s known as a Contingency Return. In such cases, the ailing astronaut can be transported back to Earth in just 3-5 hours, typically landing in the Kazakh steppe. Once on the ground, they’re swiftly transferred to facilities like NASA’s Johnson Space Centre in Houston or the Russian Space Agency’s medical centre for comprehensive care.

Still, this measure is considered a last resort. The priority is always to manage the condition onboard, because the physical strain of re-entering Earth’s gravity can worsen some medical issues.

In the ISS’s 20-plus years of operation, no astronaut has ever had to be evacuated due to a medical emergency. There have been a few incidents worth noting:

1. In 2013, an astronaut experienced kidney stone symptoms, but medication helped manage the pain until he returned to Earth.
2. In 2020, a Russian cosmonaut developed an infection and was successfully treated with antibiotics onboard.
3. Other common complaints have included back pain, rashes, toothaches, and eye irritation, all resolved in orbit.

Despite the odds, astronauts undergo thorough health screenings before missions, reducing the likelihood of serious conditions surfacing in space. But microgravity presents its own set of risks.

Common Health Risks In Space

The following conditions are known to be more likely during long-duration missions:

1. Muscle atrophy and bone density loss, due to the absence of gravity
2. Cardiac rhythm disturbances, as the heart adapts to less exertion
3. Swelling in the face and upper body from fluid redistribution
4. Visual changes, including “spaceflight-associated neuro-ocular syndrome" (SANS)
5. Insomnia and psychological stress, from confined environments and disrupted day-night cycles
6. Greater susceptibility to infections, as microgravity may weaken the immune system

Robots and AI Doctors

Looking ahead to longer missions – especially to the Moon or Mars – NASA, ESA, and private partners like SpaceX are investing in automated robotic doctors, telemedicine, and AI-assisted diagnostics. Since immediate return won’t be an option for deep-space missions, these technologies could prove vital.

Location :

United States of America (USA)

First Published:

News world What If An Astronaut Gets Sick In Space? This Is NASA's Plan