NASA is considering accelerating the return of its crew from the International Space Station (ISS) due to an unspecified medical issue affecting one of the astronauts, who had to cancel a spacewalk scheduled for today, the agency said. A NASA spokeswoman stated that the astronaut, whose name was not disclosed, is in stable condition inside the space lab.

“Conducting our missions safely is our highest priority, and we are actively evaluating all options, including the possibility of bringing an early end to the Crew-11 mission,” the spokeswoman said in a statement last night.

In an earlier statement, NASA said it was following up on a crew member medical issue that arose Wednesday afternoon.

Astronauts typically stay on the ISS for six to eight months, during which time they have access to basic medical equipment and medicines for certain types of emergencies.

The four-member Crew-11 team includes American astronauts Gina Cardman and Mike Finke, Japanese astronaut Kimiyaya Yui, and Russian cosmonaut Oleg Platonov. They have been aboard the station since August and were scheduled to return this year, around May. Finke, who serves as the station commander, and Cardman, a flight engineer, were scheduled to conduct a 6.5-hour spacewalk today to install instruments outside the station.

NASA maintains strict confidentiality regarding medical issues on the ISS, and astronauts rarely disclose or discuss their illnesses publicly. Spacewalks are physically demanding and high-risk operations that require months of training. In 2024, NASA canceled a planned spacewalk at the last minute after an astronaut experienced “discomfort in his spacesuit.”