Tom Marshburn and Kayla Barron had to replace one of the antennas on the outer hull of the station.

The U.S. National Aeronautics and Space Administration (NASA) has decided to postpone the planned Tuesday launch of two astronauts into space from the International Space Station (ISS). The agency noted on its Twitter page that it “received a notification of debris approaching the station.”

“Due to the inability to properly assess the risk that astronauts may be exposed to, we decided to postpone the planned November 30 spacewalk until more information becomes available,” NASA said.

Astronauts Tom Marshburn and Kayla Barron had to replace one of the antennas on the outer hull of the station. It was assumed that this operation would last six and a half hours. As previously reported in the department, the antenna has recently stopped transmitting a signal. Although its failure does not significantly affect the functioning of the ISS, NASA preferred to have a fully operational communication system.

Russians Anton Shkaplerov and Pyotr Dubrov, Americans Mark Vande Hei and Raja Chari, and German Matthias Maurer are also on duty at the ISS.