A medical emergency aboard the International Space Station (ISS) has forced the National Aeronautics and Space Administration (NASA) to order the early return of four Crew-11 members, leaving just three astronauts to maintain the orbital laboratory until replacements arrive in mid-February.
The unprecedented situation has indefinitely postponed critical spacewalks and severely limited station operations.
NASA announced on 7 January that a medical concern with an unidentified crew member arose on Wednesday afternoon, prompting the immediate cancellation of a scheduled spacewalk for Thursday. By the following day, the space agency had escalated its response, with administrator Jared Isaacman ordering the entire Crew-11 mission to evacuate aboard their Dragon Endeavour capsule.
The Crew Left Behind
The early departure of Crew-11 will leave just three astronauts aboard the ISS: NASA's Christopher Williams and Roscosmos cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev.
This marks the smallest crew aboard the space station in over a decade, raising serious questions about operational capabilities. The station typically hosts seven crew members who rotate responsibilities across scientific research, maintenance, and emergency preparedness.
'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,' Isaacman said during a Thursday news briefing. The affected astronaut's identity and condition remain undisclosed due to medical privacy protocols, though officials emphasised the crew member is stable and does not require emergency evacuation procedures.
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— NASA (@NASA) January 8, 2026
Critical Operations on Hold
The skeletal crew faces severe limitations that will persist until SpaceX Crew-12 arrives. Most critically, U.S. spacewalks are effectively impossible with only one NASA astronaut aboard.
The cancelled spacewalk, designated U.S. Spacewalk 94, was intended to prepare the station's 2A power channel for future installation of International Space Station Roll-Out Solar Arrays. The six-and-a-half-hour excursion would have seen NASA astronauts Mike Fincke and Zena Cardman routing cables and installing modification kits on the port side truss structure.
Standard spacewalk protocols require at least two trained EVA crew members outside the station, plus additional support personnel inside monitoring systems and communications. With Williams as the sole U.S. astronaut, such operations become logistically impossible until reinforcements arrive.
Dr Simeon Barber, a space scientist at the Open University, told the BBC that understaffing forces difficult choices. 'The space station is designed to be operated by a certain number of crew; if it is not sufficiently manned, those who remain on board would have to hold off on certain projects,' he said.
At the same time, Don Platt, a professor at Florida Tech and a former ISS engineer, explained the operational impact to NPR. 'That means, basically, the crew members that are there are pretty much just concentrating on making sure the space station can continue to run, do any maintenance requirements that they may have,' he said. 'A lot of the science will have to be postponed.'
Dr James Polk, NASA's chief health and medical officer, explained the decision to return the crew early in the Thursday press conference.
'We have a very robust suite of medical hardware on board the International Space Station, but we don't have the complete amount of hardware that I would have in the emergency department to complete a workup of a patient,' he said, adding that completing a full diagnostic evaluation would be best achieved on the ground.
Timeline for Relief
Crew-11, which arrived at the ISS on 2 August 2025, was originally scheduled to return in late February 2026. The team includes NASA astronauts Zena Cardman (commander) and Mike Fincke (pilot), JAXA astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov.
Isaacman noted in the briefing that the situation doesn't require emergency return protocols, allowing mission control to select optimal splashdown conditions over the coming days rather than forcing immediate undocking. The Crew-11 team will depart the space station within 'days,' he said.
Crew-12 remains scheduled to launch aboard SpaceX's Falcon 9 rocket by 15 February, though NASA is evaluating options to accelerate this timeline. Until then, Williams, Kud-Sverchkov, and Mikaev must maintain the £115 billion ($150 billion) orbital laboratory with significantly reduced capabilities.
The medical incident marks an extraordinary moment in ISS history. Whilst individual spacewalks have been cancelled for various reasons, NASA has never before terminated an entire crew rotation early due to a medical emergency, highlighting the unprecedented nature of the current situation.
