In a first, NASA orders astronauts home after unspecified medical issue

“The crew is highly trained, and they came to the aid of their colleague right away.”

NASA officials said Thursday they have decided to bring home four of the seven crew members on the International Space Station after one of them experienced a “medical situation” earlier this week.

The space agency has said little about the incident, and officials have not identified which crew member suffered the medical issue. James “JD” Polk, NASA’s chief health and medical officer, told reporters Thursday the crew member is “absolutely stable” but that the agency is “erring on the side of caution” with the decision to bring to return the astronaut to Earth.

The ailing astronaut is part of the Crew-11 mission, which launched to the station August 1 and was slated to come back to Earth around February 20. Instead, the Crew-11 astronauts will depart the International Space Station (ISS) in the coming days and head for reentry and a parachute-assisted splashdown in the Pacific Ocean off the coast of California.

“After discussions with our chief health and medical officer, Dr. JD Polk, and leadership across the agency, I’ve come to the decision that it’s in the best interests of our astronauts to return Crew-11 ahead of their planned departure,” NASA Administrator Jared Isaacman said Thursday.

The Crew-11 mission is led by commander Zena Cardman, 38, who is wrapping up her first mission to space. Second in command is pilot Mike Fincke, a 58-year-old astronaut on his fourth spaceflight. Japanese astronaut Kimiya Yui, 55, and Russian cosmonaut Oleg Platonov, 39, round out the crew.

Isaacman said NASA will release more information about the schedule for Crew-11’s undocking and reentry within the next 48 hours. The crew will home home aboard the same SpaceX Crew Dragon spacecraft they launched in more than five months ago. The entire crew must return to Earth together because they rely on the same Dragon spacecraft as a lifeboat.

“For over 60 years, NASA has set the standard for safety and security in crewed spaceflight,” Isaacman said. “In these endeavors, including the 25 years of continuous human presence onboard the International Space Station, the health and well-being of our astronauts is always and will be our highest priority.”

Polk, a physician who has served as NASA’s chief medical officer since 2016, said the agency is not ready to release details about the medical issue, citing privacy concerns. “I’m not going to speak about any particular astronaut or any particular specific diagnosis,” Polk said. “I’d ask that we still respect the privacy of the astronaut.”

Two of the Crew-11 astronauts, Cardman and Fincke, were preparing to head outside the space station on a spacewalk early Thursday. Spacewalk preps at the space station include a period of time breathing high concentrations of oxygen to purge nitrogen from the astronauts’ bloodstreams, a mitigation to avoid decompression sickness when crew members are sealed inside their spacesuits’ pure oxygen atmosphere.

Polk said whatever happened Wednesday “had nothing to do” with preparing for the spacewalk. “This was totally unrelated to any operations onboard,” he said. “It’s mostly having a medical issue in the difficult areas of microgravity with the suite of hardware that we have at our avail to complete a diagnosis.”

Yui radioed mission controllers in Houston on Wednesday afternoon requesting a private medical conference with a flight surgeon, then asked ground teams to turn on camera views inside the station ahead of the session. Medical sessions are carried out on private radio channels, and are not heard on the regular communication loops between the space station and mission control. Those open loops are streamed around the clock online, but NASA removed the audio feed from YouTube soon after the crew asked for the medical conference.

NASA publicly revealed a medical concern with one of the astronauts later Wednesday afternoon, then announced late Wednesday night that officials were considering bringing the crew home early.

“I won’t go into specific details about the medical incident itself,” Polk said. “But the crew is highly trained, and they came to the aid of their colleague right away, and that’s part of why we do that training.”

The space station is stocked with medical gear and medications to help astronauts respond to emergencies. Crew members are trained to perform ultrasounds, defibrillate patients, and start IVs, among other things. The medical treatment available on the ISS is akin to what an EMT might provide in transit to a hospital, former astronaut Tom Marshburn, himself a medical doctor, said in 2021.

“We have a very robust suite of medical hardware onboard the International Space Station, but we don’t have the complete amount of hardware that I would have in the emergency department, for example, to complete the workup of a patient,” Polk said.

Space station managers will take a few days to determine when the Dragon spacecraft will leave the station. SpaceX will dispatch a recovery ship from Southern California to sail for the splashdown zone in the Pacific, and officials will assess weather and sea conditions before selecting the best opportunity to depart the station. Like every crew return, the vessel will be staffed with medical personnel to examine the astronauts after exiting from the Dragon capsule.

“Because the astronaut is absolutely stable, this is not an emergent evacuation,” Polk said. “We’re not immediately disembarking and getting the astronaut down.”

But without a confirmed diagnosis of the astronaut’s medical issue, there’s some “lingering risk” for the astronaut’s health if they remained in orbit, Polk said. That’s why Isaacman and his deputies agreed to call an early end to the Crew-11 mission.

This was the most significant decision of Isaacman’s young tenure as NASA administrator. He was sworn in as NASA chief last month after clearing a confirmation vote in the Senate. Before taking the helm at NASA, Isaacman charted a career as an entrepreneur and private astronaut, flying to space twice on commercial missions with SpaceX.

After Crew-11’s departure, the space station will operate with a smaller crew of three until the arrival of SpaceX’s Crew-12 mission with a fresh team of astronauts next month. Isaacman said NASA and SpaceX are looking at options to move up the launch of Crew-12 from its current target date of February 15.

Until then, the station’s crew will consist of NASA astronaut Chris Williams and two Russian cosmonauts, who launched to the space station in November on a Russian Soyuz vehicle. Williams and his crewmates—Sergey Kud-Sverchkov and Sergey Mikayev—have their own lifeboat in the Soyuz spacecraft, so they will still have a ride home in the event of a future emergency.

The space station regularly operated with just three crew members for the first decade of its existence. The complex has been permanently staffed since 2000, sometimes with as few as two astronauts or cosmonauts. The standard crew size was raised to six in 2009, then to seven in 2020.

Williams will be solely responsible for overseeing the lab’s US segment until Crew-12 arrives. He will be busy keeping up with maintenance tasks, so managers will likely defer some of the station’s scientific investigations until the complex is back to a full crew.