Mike Fincke, the NASA astronaut who sparked the agency's first-ever medical evacuation from the International Space Station (ISS), has opened up about the terrifying episode that cut his mission short.

Fincke was eating dinner on January 7 aboard the ISS when he suddenly lost the ability to speak. He had been preparing for a spacewalk the next day when the incident struck like "a very, very fast lightning bolt." The episode lasted around 20 minutes, and Fincke said he felt no pain throughout.

The 59-year-old retired Air Force colonel and four-time space flier was more than five months into his mission as pilot of NASA's SpaceX Crew-11 when the crisis unfolded. His crewmates, NASA astronaut Zena Cardman, Japan Aerospace Exploration Agency (JAXA) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, immediately recognized something was wrong.

"It was completely out of the blue. It was just amazingly quick," Fincke said in an interview from Houston's Johnson Space Center. "My crewmates definitely saw that I was in distress. It was all hands on deck within just a matter of seconds."

All six crew members on the station gathered around him, and his crewmates quickly contacted flight surgeons on the ground. The station's ultrasound machine proved helpful during the emergency response, Fincke said.

Doctors have since ruled out a heart attack, and Fincke confirmed he was not choking. However, the cause of the episode remains unknown. Fincke noted the event could be related to his cumulative 549 days spent in weightlessness. He said he has undergone numerous tests since returning to Earth but cannot share further medical details, as NASA wants to protect the medical privacy of astronauts who experience health events in space.

NASA canceled the following day's spacewalk, which would have been Fincke's 10th and Cardman's first, and brought the entire Crew-11 team home early. SpaceX returned all four crew members to Earth on Wednesday (January 15), splashing down in the Pacific Ocean off the coast of Long Beach, California, more than a month ahead of schedule. The crew went directly to the hospital upon arrival.

Fincke said he felt guilty about cutting the mission short for his crewmates, but NASA's new administrator Jared Isaacman told him to stop apologizing. "This wasn't you. This was space, right?" colleagues reassured him. "You didn't let anybody down."

The unexplained incident is raising serious questions about astronaut health as NASA pushes deeper into space. The agency is now reviewing other astronauts' medical records to see if any similar events may have occurred in orbit, a review that carries increasing urgency as NASA prepares for its Artemis II mission, which is targeting an April 2026 launch to send four astronauts around the moon.

For his part, Fincke says he feels fine today and is holding out hope that he may return to space one day.