NASA has canceled Thursday’s spacewalk aboard the International Space Station while officials continue to investigate the cause of a coolant leak involving a backup radiator installed outside 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. This was first reported by Roscosmos flight controllers and later confirmed by NASA’s external station camera view, which showed remaining coolant droplets emerging from the radiator.
NASA said that the main radiator on Nauka remained functioning normally, providing full cooling to the module, adding that neither the seven-person crew nor the facility itself was in danger.
The leak follows two other similar incidents on the ISS almost a year ago. The first, in December, involved the spraying of coolant from a docked Soyuz spacecraft. The crew capsule was deemed unsafe to carry the two Russian crew members and one American crew member back to Earth.
A new capsule had to be sent as a replacement, and schedule adjustments resulted in all three remaining in orbit for a full year, six months longer than originally planned. American Frank Rubio has finally set a new record for the longest stay in orbit by a NASA astronaut. The three returned to Earth last month.
An investigation into the cause of the Soyuz leak concluded that it was most likely caused by a small meteoroid hitting the spacecraft.
A similar incident occurred in January when a Russian cargo ship also experienced a leak. This is also thought to be caused by a small object hitting the vehicle.
The first of two spacewalks, which was supposed to take place on Thursday, involved Loral O’Hara of NASA and Andreas Mogensen of the European Space Agency. When it finally begins, the pair will collect samples for analysis in an effort to find out whether there are microorganisms on the outside 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 in space, even if it means having to wait longer for space travel.”
Once the radiator leak review is complete, NASA will announce new dates for the two spacewalks.