Officials with the U.S. space agency NASA has postponed a spacewalk scheduled for Tuesday at the International Space Station (ISS).
NASA astronaut Mark Vande Hei and Japan Aerospace Exploration Agency astronaut Akihiko Hoshide had been prepared to conduct the spacewalk to continue the upgrade to the station's solar panel array. But officials say Vande Hei has a minor medical issue, requiring the activity be put off.
The agency did not disclose the issue but said it was not a medical emergency.
NASA says the spacewalk is not time-sensitive and crew members are continuing with other station work and activities. They say the ISS teams are assessing the next available opportunity to conduct the operation, sometime following the SpaceX cargo ship resupply launch planned for August 28 and spacewalks scheduled by the Russian team on September 2 and 8.