"I felt no pain and have no memory of the incident."
— NASA astronaut Mike Fincke, on the 20-minute episode that led to the first medical evacuation in the ISS's 25-year history.

A Medical Emergency in Orbit: The First-Ever ISS Evacuation

A sudden medical incident aboard the International Space Station in January 2026 triggered the station’s first-ever medical evacuation, forcing the early return of four crew members and accelerating the launch of a replacement mission. NASA astronaut Mike Fincke later identified himself as the affected crew member, revealing that doctors have yet to determine the cause of the episode.

The Medical Incident & Evacuation

Timeline of the Episode

On January 7, 2026, NASA astronaut Mike Fincke experienced a sudden and alarming medical episode. He reported a sudden inability to speak, felt no pain, and had no memory of the incident, which lasted approximately 20 minutes. His crewmates observed his distress and immediately contacted flight surgeons on Earth. The ISS’s onboard ultrasound machine was utilized during the response.

"I have not experienced a similar event before or since."
— Fincke, confirming the episode was unprecedented in his career.

Following the incident, NASA canceled a spacewalk scheduled for January 8, which was to be performed by Fincke and Zena Cardman. On January 8, NASA announced the decision to return all four Crew-11 astronauts to Earth earlier than planned. The agency stated the decision was based on a medical concern affecting one crew member, who was reported to be in stable condition. The specific nature of the condition and the astronaut’s identity were withheld, citing medical privacy protocols.

The Evacuation and Return

On January 12, Fincke, who was commanding Expedition 74, transferred control of the ISS to Roscosmos cosmonaut Sergey Kud-Sverchkov in a formal change-of-command ceremony.

The four Crew-11 astronauts—NASA astronauts Zena Cardman and Mike Fincke, Japanese astronaut Kimiya Yui, and Russian cosmonaut Oleg Platonov—undocked from the ISS aboard the SpaceX Crew Dragon Endeavour on January 14 at 5:05 p.m. EST. The spacecraft splashed down off the coast of Southern California on January 15 at approximately 3:41 a.m. EST, concluding a 167-day mission.

Upon landing, the crew was transported to Scripps Memorial Hospital in San Diego for evaluation before proceeding to NASA's Johnson Space Center in Houston for postflight reconditioning. NASA confirmed that the crew remained stable throughout the entire return process.

Identification and Medical Status

On March 18, 2026, Mike Fincke publicly identified himself as the crew member who experienced the medical incident. He stated that his condition stabilized quickly due to his crewmates’ response and guidance from NASA flight surgeons. Fincke reported that he was doing well and continuing standard post-flight reconditioning.

Fincke later provided additional details, stating that doctors have not identified the cause of the episode. Medical professionals have ruled out a heart attack, and Fincke confirmed he was not choking. Other potential causes—including those possibly related to prolonged microgravity exposure—remain under investigation. NASA is reviewing other astronauts' medical records for any related occurrences that may have happened in space. Fincke noted he cannot provide further details to protect the medical privacy of other astronauts.

Impact on ISS Operations

The departure of Crew-11 left the ISS with a reduced crew of three: NASA astronaut Chris Williams and Russian cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev.

With this reduced staffing, NASA announced it would temporarily suspend routine and emergency spacewalks, as these require backup from additional crew members. The reduced crew size was also expected to lead to a temporary decrease in scientific activities, with operations focused primarily on station maintenance.

Replacement Mission: SpaceX Crew-12

Launch and Docking

Following the medical evacuation, NASA and SpaceX accelerated the launch of the Crew-12 replacement mission. The mission’s original target date of February 15 was moved to an earlier window.

After multiple launch attempts were postponed due to weather and scheduling conflicts, the Crew-12 mission launched on February 13, 2026, at 5:15 a.m. EST from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. A Falcon 9 rocket carried the Crew Dragon capsule, named "Freedom," into orbit. The first stage of the Falcon 9 successfully landed at Landing Zone 40 approximately eight minutes after launch.

The Crew Dragon Freedom docked with the ISS on February 14, 2026, at approximately 3:15 p.m. EST, concluding a 34-hour journey. The arrival restored the station’s crew complement to seven individuals.

Crew Composition

The Crew-12 mission consists of:

• Jessica Meir (NASA, commander): Second spaceflight; previously spent 205 days on the ISS during Expedition 61/62 and participated in the first all-female spacewalks.
• Jack Hathaway (NASA, pilot): First spaceflight; U.S. Navy commander selected as an astronaut in 2021.
• Sophie Adenot (European Space Agency, mission specialist): First spaceflight; engineer and former helicopter test pilot, selected as an ESA astronaut in 2022.
• Andrey Fedyaev (Roscosmos, mission specialist): Second spaceflight; previously served as a cosmonaut on the ISS during NASA’s SpaceX Crew-6 mission in 2023.

The crew is scheduled for an approximately eight-month mission aboard the ISS.

Mission Objectives and Research

During their stay, the Crew-12 astronauts are scheduled to conduct research projects including:

• Ultrasound scans of blood vessels to study circulation changes in microgravity.
• Pharmaceutical research on pneumonia-causing bacteria.
• Testing of a filter designed to convert drinking water into emergency IV fluid.
• Evaluation of an ultrasound system using artificial intelligence and augmented reality for diagnosis without immediate ground expert intervention.
• Simulated lunar landing tests to assess gravity’s effects on the human body and cognition.
• Research on space-based food production and the effects of microgravity on blood flow.
• Studies on muscular strength, brain imaging, meditation, and exercise science.

Pre-Launch Activities & Scheduling

Prior to launch, NASA and mission partners held news conferences on January 30 at NASA’s Johnson Space Center in Houston. The crew entered quarantine on January 28 and transferred to Kennedy Space Center in Florida on February 6.

The Falcon 9 rocket completed a static fire test on February 8 at 3:16 a.m. EST at Space Launch Complex 40. The crew participated in a dry dress rehearsal, including a full run-through of launch day operations.

FAA Authorization

The Federal Aviation Administration (FAA) authorized the Falcon 9 rocket to resume flights on February 6, ending a four-day grounding period. The grounding stemmed from an issue during a Falcon 9 launch on February 2, in which the rocket's upper stage failed to perform its deorbit burn after deploying Starlink satellites. The FAA concluded its investigation, identifying the probable root cause as the stage 2 engine's failure to ignite before the deorbit burn. SpaceX implemented technical and organizational preventative measures.

Weather & Scheduling Factors

The Crew-12 launch schedule was also affected by the Artemis 2 lunar mission, which was scheduled for a nearby timeframe. NASA Commercial Crew Program manager Steve Stich outlined several scenarios regarding the interdependency of the two missions’ schedules. The Artemis 2 mission was subsequently delayed to March due to a hydrogen leak in its Space Launch System rocket, which cleared the launch window for Crew-12. Weather forecasts for the February 13 launch indicated a 90% probability of favorable conditions.

Broader Context: Space Medicine & Health Challenges

Common Health Issues in Space

According to medical research and NASA data, astronauts face several common health challenges during spaceflight:

• Skin irritation: Dermatological conditions occur at rates approximately 25 times higher than on Earth due to the cold, dry, low-humidity spacecraft environment and limited hygiene options.
• Congestion and headaches: Most astronauts experience these, especially early in a mission, due to fluid shifts toward the head in microgravity.
• Sleep disruption: The ISS’s 90-minute orbital period creates 16 sunrises and sunsets daily, disrupting circadian rhythms.
• Musculoskeletal injuries: A NASA study recorded 219 in-flight injuries in the US space program, with hand injuries being the most frequent. Exercise, while crucial for combating bone and muscle loss, is a leading source of injuries.

Space-Specific Conditions

• Spaceflight Associated Neuro-ocular Syndrome (SANS): Affects up to 70% of astronauts on long-duration missions, causing vision changes due to headward fluid shifts altering eye pressure.
• Blood clots: In 2020, a blood clot was discovered in an astronaut’s jugular vein, treated via telemedicine over 90 days.

Historical Context

This was the first medical evacuation from the ISS in its 25-year operational history and the first instance in 65 years of human spaceflight where NASA shortened a mission due to an astronaut’s illness. The Soviet space program had recorded instances, including cosmonaut Vladimir Vasyutin’s early return from the Salyut 7 space station in 1985 due to a serious infection.

Medical Training & Equipment

Each ISS mission includes a designated Crew Medical Officer, who may be a qualified doctor or extensively trained in space medicine procedures. CMOs can perform basic examinations, administer medications, and conduct telemedicine consultations with specialists on Earth. The ISS is equipped with medical resources including first aid equipment, suture tools, pharmaceutical treatments, and dental procedure instruments, but does not have the comprehensive diagnostic capabilities of a ground-based medical facility.