NASA said on Wednesday it was postponing a spacewalk that was scheduled for Thursday, citing a “medical concern” with one of the crew members. The space agency did not name the astronaut involved but confirmed later the issue was related to a “single crew member who is stable” and officials are considering next steps.

NASA has spent the last few weeks getting ready for two spacewalks at the International Space Station (ISS), its first in eight months. But just hours before NASA astronauts Mike Fincke and Zena Cardman were due to begin the first of the two walks on Thursday,

NASA is postponing a spacewalk due to a "medical concern with a crew member" on the International Space Station. It did not say who was experiencing the issue, but the situation was stable.

A sudden medical concern aboard the ISS forced NASA to delay a planned spacewalk, raising questions about Crew 11’s schedule and how astronaut health can reshape missions in orbit.

On Thursday, a pair of astronauts will venture outside the space station to prepare for the future installation of roll-out solar arrays that will help power its deorbit in 2030.