NASA is contemplating bringing its crew back from the International Space Station (ISS) earlier than planned due to a medical issue that has not been disclosed.

This unusual decision follows the agency’s cancellation of a spacewalk that was initially slated for Thursday, as reported by Reuters.

“Our top priority is the safety of our missions, and we are carefully considering all our options, including potentially concluding Crew-11’s mission sooner,” a NASA spokesperson stated on Wednesday evening, according to NBC News.

The astronaut, whose identity has not been revealed, is reportedly in stable condition despite the medical concern, as detailed by the news outlet.

Previously, NASA had issued a statement indicating they were “monitoring a medical concern with a crew member that became apparent on Wednesday afternoon.”

 In a previous statement, NASA revealed it was “monitoring a medical concern with a crew member that arose Wednesday afternoon.”

The four-person Crew-11 crew consists of U.S. astronauts Zena Cardman and Mike Fincke, Russian cosmonaut Oleg Platonov and Japanese astronaut Kimiya Yu.

Crew-11 mission astronauts walk out of the Neil A. Armstrong Operations and Checkout Building before heading to pad 39A for launch to the International Space Station (ISS) at the Kennedy Space Center on Aug. 1, 2025, in Cape Canaveral, Florida. (Paul Hennessy/Anadolu via Getty Images)

Fincke, the mission’s commander, and flight engineer Cardman were anticipated to complete a 6.5 hour spacewalk on Thursday to install hardware outside the ISS.

Astronauts typically live aboard the ISS for stints of six to eight months, and are equipped with basic medical equipment and medications in the event of an emergency. The crew set off for their current eight-month mission from Florida in August and were set to return to Earth in May.

Falcon 9, Dragon, and Crew-11 launch to the International Space Station at LC-39A in Kennedy Space Center on Aug. 1, 2025. (Austin DeSisto/NurPhoto via Getty Images)

Spacewalks are highly strenuous and involve months of training.

 Last year, NASA canceled a planned spacewalk after an astronaut reportedly experienced “spacesuit discomfort.” In 2021, U.S. astronaut Mark Vande Hei’s had his spacewalk called off due to a pinched nerve. 

NASA did not immediately respond to Fox News Digital’s request for comment.