NASA has postponed a planned International Space Station (ISS) spacewalk due to a 'medical concern' with a crew member. The spacewalk, involving astronauts Mike Fincke and Zena Cardman, was intended to install hardware for future solar arrays. The agency confirmed the affected crew member is stable but is considering an early return for the Crew-11 mission.

This potential schedule change creates a logistical challenge, as the replacement crew, Crew-12, is not scheduled to launch until mid-February. While reports mention a request for a private medical conference by JAXA astronaut Kimiya Yui, NASA notes such requests are routine and may be unrelated. This incident highlights the complex medical protocols and contingency planning required for long-duration spaceflight, where crew health can significantly impact mission timelines and station staffing.