Russian ISS Module Suffers From Coolant Leak, Prompts Investigation After Third Incident in 10 Months

The Russian space agency, Roscosmos, searches for answers after a leak from a portion of the International Space Station (ISS) has been detected.

Nauka Module Leak-a-Boo

On October 9, a radiator on the Russian portion of the ISS started leaking coolant. Flight controllers noticed flakes from one of the two radiators on the Nauka module at around 1 PM EST. They informed the station's crew, who visually confirmed the leak.

It was not clear how much coolant leaked from the radiator and for how long. In an official statement, NASA reported that they were informed that the leak was with a backup radiator. This radiator was originally located on the Rassvet module launched to ISS in 2010 but was later transferred to Nauka as part of a series of spacewalks. The Nauka module, the Multipurpose Laboratory Module (MLM), was installed on the ISS in July 2021.

In an official statement, Roscosmos said that Nauka's main thermal control system is working well, and neither ISS nor its crew are in danger. In an independent assessment by NASA, the agency confirmed that the leakage has no impact on the crew or the operations of the space station. However, the station's crew closed the shutter on windows on the U.S. segment of the station to avoid contamination from the leaking coolant.

This incident is the third time in 10 months that a Russian vehicle at the ISS has experienced a coolant leak. In December 2022, the Soyuz MS-22 spacecraft lost its coolant three months after arriving at the ISS. Because of this, Roscosmos decided to replace it with an uncrewed Soyuz MS-23, keeping the crew that launched to the station on Soyuz MS-22 outside the Earth for an additional six months.

In February 2023, another coolant leak was experienced by an uncrewed Progress MS-21 cargo spacecraft. This event occurred just before the spacecraft, launched in October 2022, was scheduled to undock from the ISS.

The two leaks raised doubts about the design and manufacturing of the spacecraft. Roscosmos responded by claiming that leaks resulted from impacts with orbital debris or micrometeoroids.

The officials from NASA accepted this conclusion. According to ISS program manager Joel Montalbano, they could not find anything other than some external force or debris based on the information they received from their Russian colleagues.

Cooling System for ISS

With an acre of solar panels, the International Space Station generates between 75 and 90 kilowatts of power. This power is used by the station's systems, such as laboratory experiments, storage freezers, and life support.

Consuming that amount of power generates a lot of waste heat, which needs to be released into space. To make this possible, the International Space Station has a cooling system that transfers heat from the inside to the outside environment with temperatures as low as -454 degrees Fahrenheit (-270 degrees Celsius). Every system that generates heat inside the ISS comes with a radiator to cool it down. These radiators are the ones responsible for ejecting the system heat into space.