Leaks on the ISS are most worrying for astronaut safety

While NASA and the Russian Federal Space Agency (Roscosmos) are addressing the issue of leaks on the ISS, this remains the top “safety risk” for astronauts on board, according to a report by the Office NASA’s Office of Inspector General (OIG) announced last month.

NASA officials, interviewed by the Washington Post, said they were monitoring four cracks and 50 other “areas of concern” on the ISS. The cracks were “covered by Roscosmos with a combination of sealant and patch”. At the same time, corrective measures are still being implemented. However, the leak area remains the top risk, at a 5 on a 5-point scale, in NASA’s internal risk assessments, according to the OIG.

“We have repeatedly communicated the seriousness of the leaks, including when I was in Russia earlier this year,” deputy director Jim Free added in the interview. Because the leaks were near the station’s door, Free said Roscosmos agreed to NASA’s request to shut down the station as much as possible: “We reached an agreement that they shut down in the evening.”

NASA astronauts also stay on the American side of the orbital complex to be close to their escape vehicle, in case an evacuation is necessary. However, NASA has repeatedly emphasized that the leak poses no immediate threat to astronauts.

“Currently there is no impact on crew safety or vehicle operations, but it is something everyone needs to pay attention to,” ISS program director Joel Montalbano said in a press conference in February 2024.

The ISS leaked coolant at the end of the Russian module when the Progress spacecraft docked with the station, NASA’s ISS program manager Joel Mantalbano announced in February at the Kennedy Space Center. According to Montalbano, that area is about 0.9 m long.

The leak has lasted five years and patching measures have been implemented since its discovery, Roscosmos authorities said in an online press conference on September 27. Repairs have now significantly reduced the highest leak observed in April 2024 (nearly 1.7 kg per day) to 2.4 pounds (just over 1 kg) per day.

The ISS is expected to operate until 2030 to serve NASA’s personnel needs and provide commercial research in low Earth orbit. Over the next decade, NASA hopes to have a series of commercial space stations ready to take over operations.

NASA’s OIG is monitoring a number of other risks that could threaten the long-term maintenance of the ISS, from a sudden micrometeoroid impact to supply chain issues.

SpaceX has been tasked with building a large Dragon-class spacecraft to remove the ISS from orbit, under a contract awarded by NASA earlier this year. OIG said it will learn more about the schedule, costs and risks associated with the new vehicle and the station relocation plan.