By Jackie Wattles, CNN
The spacewalk was scheduled on the International Space Station. Photo: Supplied / NASA via Paihau-Robinson Space Team
NASA said it was postponing a spacewalk that was scheduled, citing a "medical concern" with one of the crew members.
The space agency did not provide additional information about the issue or name the astronaut involved.
"Due to medical privacy, it is not appropriate for NASA to share more details about the crew member," the space agency said in a statement. "The situation is stable. NASA will share additional details, including a new date for the upcoming spacewalk, later."
Two NASA astronauts - Mike Fincke and Zena Cardman - were slated to exit an airlock aboard the International Space Station on Thursday (US time) to finish preparing a power channel where a new solar array is set to be installed.
The spacewalk would be a first for Cardman, a 38-year-old geobiologist who was selected for the astronaut corps in 2017.
Fincke, who has been an astronaut since 1996, has participated in nine prior spacewalks. Venturing outside the space station again would make him the sixth American astronaut to conduct 10 spacewalks, said Bill Spetch, NASA's operations integration manager for the orbiting laboratory, during a Wednesday news briefing.
NASA does not typically share details about medical issues that affect astronauts. Information about the impact of spaceflight on the human body or other medical concerns that occur during missions are generally made public as part of broader scientific studies and research, and specific astronauts are usually not identified.
The Artemis I Space Launch System (SLS) and Orion spacecraft, atop the mobile launcher, are being prepared for a wet dress rehearsal to practice timelines and procedures for launch. The first in an increasingly complex series of missions, Artemis I will test SLS and Orion as an integrated system prior to crewed flights to the Moon.
Through Artemis, NASA will land the first woman and first person of colour on the lunar surface, paving the way for a long-term lunar presence and using the Moon as a steppingstone on the way to Mars.
Conditions such as space adaptation syndrome - an ailment characterized by vomiting and vertigo that is experienced by many astronauts during their first hours in microgravity - only came into focus after years of research and revelations in academic journals. The condition is common, however, and has affected astronauts dating back to the beginning of spaceflight.
An incident in which an astronaut experienced a case of jugular venous thrombosis, a dangerous condition in which a blood clot can form in a person's jugular vein, was also revealed in an academic journal. The identity of the astronaut impacted has never been made public.
Additionally, after SpaceX's Crew-8 mission returned from the space station in October 2024, one of the four crew members experienced a "medical issue" and was flown to a hospital in Florida.
The space agency did not provide further details at the time, saying in a statement only that the crew member was "in stable condition" and "under observation as a precautionary measure." The identity of the crew member is still unknown.
- CNN