NASA crew to make rare early return to Earth after medical issue in space

A view of the International Space Station with the Earth 265 miles below seen during a space walk in December 2021. (NASA via CNN Newsource)

Four astronauts will return from the International Space Station more than a month ahead of schedule after an unnamed crew member experienced a medical issue.

The incident marks the first time in history NASA has brought astronauts home from the space station early because of a medical issue.

NASA has not provided details about the nature of the problem, citing privacy concerns. The agency typically does not discuss the specifics of health matters related to astronauts.

A SpaceX Crew Dragon capsule will bring the four-person crew home, disembarking from the ISS as soon as Wednesday at 5 p.m. ET. The spacecraft is then expected to splash down off the coast of California early the following morning, NASA said in a statement Friday evening.

The affected astronaut is in stable condition, NASA previously confirmed, and is not expected to receive special treatment during the return trip, said Dr. James Polk, NASA’s chief health and medical officer at the agency’s headquarters. The astronaut would also be best served by being evaluated on the ground, Polk added.

“We have a very robust suite of medical hardware on board the International Space Station,” Polk noted during a Thursday news conference. “But we don’t have the complete amount of hardware that I would have in the emergency department, for example, to complete a workup of a patient.

“And in this particular incident,” he added, “we would like to complete that work up, and the best way to complete that workup is on the ground.”

The returning group, which includes American astronauts Mike Fincke and Zena Cardman, Japan Aerospace Exploration Agency astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, makes up NASA’s SpaceX Crew-11. The mission, part of the orbiting laboratory’s regular staffing rotation, was expected to conclude no earlier than next month. Typically, NASA wouldn’t bring a team such as this back to Earth before another was in place.

NASA’s newly appointed administrator, Jared Isaacman — who has twice flown to orbit on private SpaceX missions — said he made the call to bring the group of four astronauts home.

Isaacman said during a news briefing Thursday that his decision was informed by the fact that four crew members are slated to launch to the space station on NASA’s Crew-12 mission in the coming weeks, and the agency is assessing ways to expedite that launch. The mission had been slated to take off around mid-February.

The Crew-11 team will depart the space station within “days,” Isaacman said.

Delayed spacewalk

NASA revealed the astronaut’s medical concern on Wednesday when it announced that the agency was opting to postpone a spacewalk, citing the undisclosed “medical concern.”

“These are the situations NASA and our partners train for and prepare to execute safely,” NASA noted in a statement.

When the Crew-11 astronauts return, it will leave only one NASA astronaut on board the football-field-size orbiting laboratory: Chris Williams, who arrived at the space station in late November on board a Russian Soyuz capsule as part of a ride-sharing agreement between the U.S. and Russia.

Officials on Thursday said Williams is well prepared to handle any tasks that come his way, and they are confident he will be joined shortly by the Crew-12 astronauts to return staffing to normal levels.

“This is one of the reasons why we fly mixed crews on Soyuz and U.S. vehicles — because we want to make sure we have operators for both (the U.S. and Russian) segments” of the space station, said Amit Kshatriya, NASA’s associate administrator.

Dr. Farhan Asrar, a space medicine researcher and associate dean at the Toronto Metropolitan University School of Medicine, told CNN via email that health care providers face unique challenges attempting to treat or diagnose astronauts as they orbit more than 200 miles (320 kilometres) above Earth. The limitations can turn even common ailments — such as toothaches or ear pain — into difficult medical conundrums.

“Even though astronauts undergo frequent and ongoing health checks, the extreme environment of space does put a significant strain on health (stress on the heart, bone, eyes, kidneys, mood and other systems),” Asrar said.

A history of in-space medicine

NASA’s decision to withhold the affected astronaut’s name and details about their condition follows a long-established pattern. Information about the impact of spaceflight on the human body or other medical concerns that occur during missions are generally made public as part of broader scientific studies and research, and specific astronauts are not usually identified.

Conditions such as space adaptation syndrome — an ailment characterized by vomiting and vertigo that is experienced by many astronauts during their first hours in microgravity — only came into focus after years of research and revelations in academic journals. The condition is common, however, and has affected astronauts dating back to the beginning of spaceflight.

An incident in which an astronaut experienced a case of jugular venous thrombosis, a dangerous condition in which a blood clot can form in a person’s jugular vein, was also revealed in an academic journal. The identity of the astronaut impacted has never been made public.

Additionally, after SpaceX’s Crew-8 missions returned from the space station in October 2024, one of the four crew members experienced a “medical issue” and was flown to a hospital in Florida.

The space agency did not provide further details at the time, saying in a statement only that the crew member was “in stable condition” and “under observation as a precautionary measure.” The identity of the crew member is still unknown.

Over the past 25 years that the space station has operated, NASA has worked to respond to a “host” of medical issues, Polk noted during the Thursday briefing.

“Fortunately for us, we’ve had equipment and medications and things to be able to handle all of those such that we were able to complete the treatment and or the diagnosis on orbit,” Polk said.