This NASA astronaut suddenly couldn't speak in space: Will his experience impact future missions?

NASA astronaut Mike Fincke experienced a "medical emergency" in space earlier this year. He couldn't speak suddenly during the mission. The episode marked an early return of Crew-11, which he was part of. Months later, what he had suffered aboard the International Space Station remains a mystery.

Mike Fincke tells what he had experienced

In an interview with the Associated Press, astronaut Mike Fincke disclosed what had exactly happened on January 7, while he was still aboard the ISS.

Four-time space flier Mike Fincke told the outlet that he was eating dinner on January 7 after prepping for a spacewalk the next day when it happened.

He couldn’t talk suddenly and remembered no pain, but his anxious crewmates jumped into action after seeing him in distress and requested help from flight surgeons on the ground.

“It was completely out of the blue. It was just amazingly quick," Fincke said in an interview with The Associated Press from Houston's Johnson Space Center.

Fincke, 59, a retired Air Force colonel, reportedly said the episode lasted roughly 20 minutes and he felt fine afterwards. He said he still does. He never experienced anything like that before or since.

“My crewmates definitely saw that I was in distress,” he said, with all six gathering around him. “It was all hands on deck within just a matter of seconds," he added.

According to the report, doctors ruled out a heart attack.

Fincke said he wasn't choking, but everything else is still on the table and could be related to his 549 days of weightlessness.

He was 5 ½ months into his latest space station stay when the problem struck like “a very, very fast lightning bolt.”

SpaceX Crew-11 returned to Earth safely on January 15, eight days after the episode — meaning this wasn’t an emergency evacuation, which would have unfolded in a matter of hours.

Still a mystery

In January, when NASA first announced its first-ever medical evacuation from the International Space Station, the space agency did not spare any details about the 'medical concern' or who had suffered from it.

Fincke identified himself late in February as the one who was sick to end the swirling public speculation. But it's not known what had caused Fincke that distress.

Fincke, who prompted NASA’s first medical evacuation earlier this year, said doctors still don’t know why he suddenly fell sick at the International Space Station.

Fincke said he can’t provide any more details about his medical episode. The space agency wants to make sure that other astronauts do not feel that their medical privacy will be compromised if something happens to them, he said.

What does that mean for future missions?

There wasn’t a medical doctor on board the ISS during Fincke’s medical episode, but NASA administrator Isaacman said he doesn’t believe things would have played out differently had that been the case, CNN reported.

He did note, however, that when NASA embarks on missions to Mars, having medical professionals on board would be “additive.”

Crews may eventually be able to anticipate and plan for in-space health care, too, the report added.

For example, NASA stowed “organ chips” on board Artemis II — bone marrow samples from the astronauts to assess the effects of deep-space conditions, including radiation, on human health, CNN explained.

It added that the insights gained from the experiment could lead to individualised treatments, such as personalised medical kits, that ease the way for the astronauts to embark on longer missions — perhaps deeper into the cosmos.

What could have happened with Mike Fincke?

The strong forces and the weightlessness experienced during space travel have a variety of effects on the human body.

NASA has been studying these effects for over 50 years and groups them into five key hazard areas: radiation, isolation, distance, microgravity and hostile environments.

These forces can cause ailments including bone and muscle loss, cardiovascular issues, immune dysfunction and vision impairment.

Blood flow is one key process affected by weightlessness.

Dr Farhan Asrar, an associate professor at the Faculty of Medicine of the University of Toronto, told CNN that certain blood flow issues could potentially lead to a temporary lapse of speech.

"There is something known as a TIA, or Transient ischaemic attack, which is basically a brief episode of a neurological dysfunction, usually due to the blood flow to the brain being interrupted,” Asrar was quoted as saying.

“It tends to resolve by itself and not leave any kind of permanent damage,” he added. TIA symptoms can also include dizziness, confusion and loss of balance.

It’s not clear, however, whether Fincke experienced any additional symptoms or if his condition had anything to do with blood flow.

The crew used the space station’s ultrasound machine to assess Fincke, likely with guidance from mission control.