Spacewalks Postponed Due to Accident on Nauka Module of Russian ISS Segment

Two spacewalks by NASA astronauts postponed until analysis of the accident is complete; Roscosmos has not yet announced the cancellation of the Russian cosmonauts' spacewalk

Astronaut spacewalks from the ISS have been temporarily suspended after a coolant leak from the external radiator circuit on the Russian Nauka module. The United States National Aeronautics and Space Administration (NASA) has announced that it is postponing the two nearest spacewalks for astronauts Loral O'Hara, Andreas Mogensen, and Jasmin Moghbeli until the analysis of the causes of the accident is complete.

Russian cosmonauts are currently continuing to work on schedule, and their next spacewalk on October 25 has not been canceled.

The astronauts were scheduled to go into open space on October 12 and October 21. But NASA engineers and the flight control team canceled their spacewalks until the data on the accident has been studied.

The leak has now stopped, as reported by Roscosmos dispatchers and as evidenced by images from NASA's external station cameras, which show only residual droplets of coolant. The main radiator on Nauka continues to operate normally, providing full cooling of the module without any impact on the crew or the operation of the space station.
NASA Press Service


Accident on Nauka

On Monday, October 9, Roscosmos reported that a coolant leak had occurred on the Nauka module of the Russian ISS segment from the external radiator circuit. Roscosmos stated that the crew and the station were not in danger, and later, on October 11, it became known that the leak had been stopped.

A leak was detected from an additional radiator that was recently installed. This radiator was delivered earlier than the module, it seems, in 2010, and was actually installed and connected to the hydraulic system only this summer. The radiator is designed to dissipate heat, but there is actually no need for such heat dissipation right now. The system consists of two redundant circuits, and the coolant leak occurred from one of these two circuits, from the additional and standard ones. The leak was recorded both visually and by telemetry, and there are recordings from external cameras and from cameras that filmed through the portholes.
Sergey Krikalev, Executive Director for Manned Space Programs at Roscosmos

According to Roscosmos, on October 25, Russians Oleg Kononenko and Nikolai Chub will go into open space. They will install a radar on the Nauka module to observe the Earth's surface and launch the Parus-MGTU student nanosatellite.

Their tasks also include inspecting the leak site with its photography. The work of the cosmonauts will help specialists on Earth to find out the causes of the incident. There is no information about their cancellation yet.