While Sunita Williams is still in space, NASA detects major air leak on ISS with a daily loss of 1.7 kg

The issue, first identified in 2019 within the Zvezda module’s PrK vestibule, has undergone thorough investigation. (Image: NASA)

NASA is working diligently to resolve an air leak in the Russian section of the International Space Station (ISS), while highlighting recent improvements in reducing the leak rate.

The issue, first identified in 2019 within the Zvezda module’s PrK vestibule, has undergone thorough investigation. NASA’s Office of Inspector General recently reported that by April 2024, the leak had worsened to nearly 1.7 kilograms per day, prompting concern. This increase led the ISS program to classify it as a high-priority risk. However, NASA has made significant progress, reducing the leak rate by roughly one-third after repair efforts.

Potential Solutions and Ongoing Investigations

Investigators are still working to pinpoint the exact cause. Both NASA and Roscosmos are focusing on the welds, both internal and external, in the Zvezda module. As a safety measure, the crew keeps the hatch to the affected area closed when it’s not in use, which helps to contain the problem.

Discussions are ongoing between NASA and Roscosmos to determine acceptable limits for the leak. They have not yet agreed on what would be an "untenable" leak rate. A more drastic solution could be permanently sealing the affected hatch. However, this would result in the loss of a docking port used by Progress and Soyuz spacecraft.

This air leak is just one of several challenges NASA is facing in keeping the ISS running smoothly. Other issues include potential difficulties in obtaining spare parts, certifying Boeing’s CST-100 Starliner for crew transport, and the growing risks from space debris. As the ISS nears its planned retirement between 2028 and 2030, NASA is also preparing for its deorbit. A deorbit vehicle is being developed by SpaceX, based on its Dragon spacecraft, although this project could encounter budgetary and scheduling hurdles.

Despite these obstacles, NASA remains dedicated to ensuring the ISS operates safely and continues to collaborate with international partners to address these ongoing concerns.