### NASA’s Worries About the Aging Components of the ISS and the Outlook for Low-Earth Orbit Operations
The International Space Station (ISS) has represented a hallmark of global collaboration and human creativity for more than 20 years. Nevertheless, as its parts continue to age, worries regarding its sustainability are intensifying. A recent document from NASA’s Office of the Inspector General (OIG) brings attention to a pressing concern that has been gradually escalating: a recurring leak in a minor Russian module aboard the ISS. This issue, which has persisted since 2019, is now raising concerns about the station’s future and the broader effects on human space exploration in low-Earth orbit.
#### The ISS: A Quarter Century in Orbit
Launched in 1998, the ISS has had many of its components, particularly the Russian modules, functional for over 25 years. While the station has experienced numerous enhancements and maintenance, the degradation of its aging framework is increasingly evident. U.S. space authorities have been hesitant to publicly address the dangers posed by operating astronauts on such an aging system, yet internal documents and communications reflect rising apprehensions.
One of the most urgent matters centers around a small Russian module referred to as the PrK (Service Module Transfer Tunnel), which links the larger Zvezda module to a docking port utilized by the Progress spacecraft. This module has been experiencing leaks since September 2019, and, despite attempts by both NASA and Roscosmos (Russia’s space agency), the specific cause of the leak remains unclear.
#### Rising Leak Rates
The OIG report indicates that the leak rate has been progressively increasing. In February 2024, the rate surged from below 1 pound of atmosphere per day to 2.4 pounds per day. By April, it escalated to 3.7 pounds per day. This rise has prompted NASA to take the matter more seriously, as it poses a growing threat to the station’s functionality.
“While the precise cause of the leak is still not determined, both agencies have focused their investigation on internal and external welds,” the report mentions. Nevertheless, a conclusive solution has yet to be established.
To reduce the risk, NASA and Roscosmos have opted to keep the hatch connecting the Zvezda module to the PrK tunnel sealed. If the leakage continues to escalate, this hatch may need to be permanently closed, which would diminish the number of Russian docking ports on the ISS from four to three. This alteration would limit the station’s docking capabilities and could complicate future missions.
#### NASA’s Risk Assessment: Increasing Concerns
In public statements, NASA has downplayed the gravity of the problem, asserting that the leak is localized to the PrK tunnel and has not affected other sections of the station. However, internally, the issue has reached the utmost level of concern on NASA’s 5×5 risk matrix, which evaluates the odds and consequences of risks facing spaceflight endeavors. The Russian leaks are now regarded as a “5” in both aspects, denoting a high probability of occurrence and serious potential repercussions.
In May and June 2024, officials from NASA and Roscosmos convened to discuss the surging leak rate. The OIG report corroborates that the ISS Program has categorized the PrK tunnel leak as the highest risk in its management protocol. While Roscosmos is optimistic about their ability to monitor the situation and seal the hatch before the leak becomes untenable, there is no shared understanding between NASA and Roscosmos on what defines an “untenable” leak rate.
#### The Prospects for the ISS and Low-Earth Orbit Operations
The leak in the PrK module is merely one of the numerous challenges confronting the ISS as it nears the conclusion of its operational life. NASA and its global partners, including Russia, have agreed to maintain the station’s operations until 2028, with hopes from NASA to extend this until 2030. However, no official agreement has been finalized, leaving the future of the ISS in question.
Upon the decommissioning of the ISS, NASA intends to shift its activities in low-Earth orbit to privately run space stations. The agency has already financed preliminary development efforts by organizations like Axiom Space, Blue Origin, and Voyager Space. However, Northrop Grumman, one of the original competitors, has exited the race, citing concerns regarding profitability.
There’s also uncertainty surrounding whether any of the private space stations will be operational by 2030. If they are not, NASA may be compelled to prolong the ISS’s life even further, but this scenario presents significant challenges. Extending the life of the station would demand considerable funding for upkeep and repairs, along with assurances of continued collaboration from international partners like Russia, whose relationship with the U.S. has been strained due to geopolitical tensions, particularly following Russia’s incursion into Ukraine.
#### Financial and Logistical Hurdles
The OIG report underscores several additional obstacles that NASA encounters in maintaining the ISS and transitioning to private space stations. These include potential
