NASA Suddenly Canceled Latest ISS Mission Due To Unforeseen Medical Concerns

An astronaut currently aboard the International Space Station (ISS) is experiencing an undisclosed health issue that was bad enough to postpone the January 8 space walk, due to a "medical concern with a crew member that arose [...] aboard the orbital complex." NASA cited privacy concerns, explaining it's "not appropriate" for them to publicly share more information about the crew member in question. No one really knows what's wrong, with contrary reports remaining highly speculative. The spacewalk was going to be conducted by NASA's Zena Cardman and Michael Fincke, with two other astronauts forming Crew-11 — including Japanese astronaut Kimiya Yui, and Roscosmos astronaut Oleg Platanov.

In an email update, NASA explained a little more about the situation: "Safely conducting our missions is our highest priority, and we are actively evaluating all options, including the possibility of an earlier end to Crew-11's mission." The email further states: "These are the situations NASA and our partners train for and prepare to execute safely. We will provide further updates within the next 24 hours."

An update came in the form of a January 8 press conference held by NASA administrator Jared Isaacman. The end result: The Crew-11 mission will be ending early, with an evacuation of the four team members slated to take place at some point over the next few days.

While this event ends the space mission early, Crew-11 arrived on the ISS in August 2025, and it's already somewhat close to the end of the team's six-month stay — which, if kept on track, would have ended at the beginning of February 2026.

Space travel can be challenging in a broad sense: While in space, astronauts have a rigorous training schedule, as just three days in orbit is enough to cause a cognitive decline in health. Blood samples from astronauts have even shown startling DNA mutations in those that have spent a considerable amount of time in space, although they are still "below the overall threshold of concern."

The early end to the mission will result in the first ISS medical evacuation due to a health concern in the orbiter's 25-year history. Although, there have been previous incidents, like when a doctor helped treat an astronaut's blood clot in 2020. But while medical emergencies requiring evacuation haven't occurred, at least on this scale, there have been several unfortunate events in orbit as of late — like when Starliner stranded ISS astronauts in space for longer than intended just last year. Moreover, and although it had nothing to do with the ISS itself, in November 2025 Chinese astronauts were also stranded in space when their return module was hit with space debris. No one was injured in that particular incident.

Because of the full Crew-11 evacuation, it might be reasonable to assume more than one astronaut is facing medical distress, but that doesn't appear to be the case. Only one crew member is reported ill, and NASA is bringing the entire crew back because of its policy to keep fewer ISS residents on board than there are seats in docked space capsules. The ISS will not be empty, however, as there are still three astronauts onboard — including NASA's Chris Williams, as well as Russia's Sergei Mikayev and Sergei Kud-Sverchkov.