ISTANBUL

NASA postponed a spacewalk scheduled for Thursday outside the International Space Station (ISS) due to a “medical concern” with a crew member.

"The agency is monitoring a medical concern with a crew member that arose Wednesday afternoon aboard the orbital complex,” the US space agency said in a statement late Wednesday.

It did not share further details due to medical privacy, but added: "The situation is stable."

NASA said in a later statement that it is “evaluating all options,” including an early return for the crew.

“These are the situations NASA and our partners train for and prepare to execute safely,” it added.

The agency said it will later share additional details within 24 hours, including a new date for the spacewalk.

NASA earlier said Expedition 74, which began on Dec. 8 and will end this summer, was making final preparations for the year’s first spacewalk.

Station Commander Mike Fincke and Flight Engineer Zena Cardman were on track to hold their mission's first spacewalk on Thursday.

The spacewalk was planned to last about 6 1/2 hours to support solar array upgrades and routine maintenance as part of power channel preparations for new solar arrays.