NASA has called off Thursday’s spacewalk at the International Space Station while officials continue investigating the cause of a coolant leak involving a backup radiator attached to the outside of Russia’s Nauka module.
Another NASA spacewalk scheduled for Friday, October 20, has also been postponed.
The leak was spotted earlier this week but has now stopped. It was first reported by Roscosmos flight controllers and then confirmed by NASA external station camera views which showed residual coolant droplets emerging from the radiator.
NASA said that the primary radiator on Nauka continues to work normally, providing full cooling to the module, adding that neither the seven-person crew nor the facility itself is in any danger.
The leak follows two other similar incidents at the ISS nearly a year ago. The first, in December, saw coolant spraying from a docked Soyuz spacecraft. The crew capsule was deemed unsafe for carrying the two Russian and one American crew members back to Earth.
A new capsule had to be sent up as a replacement, and adjustments to the schedule resulted in the trio staying in orbit for an entire year, six months longer than originally planned. The American, Frank Rubio, ended up setting a new record for the longest stay in orbit by a NASA astronaut. All three returned to Earth last month.
An investigation into what caused the Soyuz leak concluded that it was likely the result of a tiny meteoroid striking the spacecraft.
A similar incident occurred in January when a Russian cargo ship also sprung a leak. This was also thought to have been caused by a small object striking the vehicle.
The first of the two spacewalks, which was supposed to take place on Thursday, involves NASA’s Loral O’Hara and the European Space Agency’s Andreas Mogensen. When it eventually gets underway, the pair will collect samples for analysis in a bid to find out whether microorganisms exist on the exterior of the orbital complex.
Responding to news of the postponement, Mogensen said in a post on social media: “I fully support the safety-first approach we always take when it comes to space, even if it means waiting a bit longer to go on our spacewalk.”
Once the review on the radiator leak has been completed, NASA will announce new dates for the two spacewalks.