The ISS currently faces another air leak which has led to the postponement of its next crewed mission. NASA announced that Axiom Mission 4 has been delayed when its four-astronaut commercial flight to the space station was postponed. The agency is withholding most of the information about the incident.

The genuine concern exists behind the scenes. According to multiple sources who talked to Ars Technica NASA is actively investigating potential structural weaknesses in a space station that has operated for almost three decades.

The International Space Station has faced problems with air leaks before. The Russian Zvezda service module has been identified as the source of a slow but steady pressure drop that began in 2019. The issue primarily centers on the PrK transfer tunnel that links the module to the Soyuz and Progress spacecraft docking port.

Russian cosmonauts performed multiple expedited repairs over time including crack patching and sealant testing. The repairs reduced the leak’s intensity to a manageable rate of approximately two pounds of air daily. The most effective long-term strategy? The simplest way to manage the air leak problem is by closing the PrK hatch whenever it’s not needed.

That approach worked—until recently.

Roscosmos declared this month that the PrK module had reached its final state of being completely sealed. NASA confirmed the success of recent repairs and reported that the PrK module had stopped leaking air.

That sounds like progress. But then a new problem emerged: The ISS experienced a continuous decline in its overall air pressure.

Two knowledgeable sources believe the hatch seals to be responsible for the current problem. Air escaping from the main station body is supposedly passing through the hatch into the PrK module which maintains normal pressure readings thereby creating the false impression that PrK has stopped leaking while the station continues to lose air.

This has left engineers scratching their heads. The situation remains unclear since the module shows no leaks after repairs were made.

The present air leakage does not pose an immediate danger but it brings up significant concerns about the sustained structural stability of the ISS. The highest risk situation involves high cycle fatigue that causes metal degradation over time, which particularly affects aluminum.

Reflect on the repeated bending motion applied to a wire. The first time, it bends. After a few times, it breaks. Metal fatigue refers to an abrupt failure that happens without any advanced signs.

The ISS which started its assembly in orbit during 1998 is coming up to its thirty-year mark of operation in space. The spacecraft has faced thirty years of extreme thermal fluctuations along with pressure shifts and structural stress.

NASA internal reports place structural cracking at the top risk level on their 5×5 risk evaluation matrix. In simple terms: Structural cracking stands as one of the agency’s primary concerns.

It’s not just theory either. Metal fatigue led to a tragic incident in 1988 when Aloha Airlines Flight 243 experienced sudden decompression mid-flight because of undetected cracks in its fuselage. The plane held together—barely.

NASA postponed the launch of the Axiom-4 mission originally planned for Thursday due to existing uncertainties.

NASA and Roscosmos now have extra time to evaluate the current situation because Axiom Mission 4 has been postponed and determine if additional troubleshooting efforts are required.

The launch date for June 18 remains tentative with conditions attached. Should the leak problem remain unresolved or intensify then the launch date may face another postponement.

Leadership and engineering teams maintain ongoing evaluations of the situation behind the scenes. According to a source knowledgeable about internal NASA conversations the team feels anxious.

NASA has not organized a press conference nor released a comprehensive explanation for the leak despite journalists and observers raising increasing questions. The only public statement to date?

The astronauts on board the International Space Station continue their standard operations in a safe manner.

And for now, that’s true. The astronauts are safe, and operations continue. The aging International Space Station shows more obvious signs of wear and fatigue which leaves everyone wondering.

A reliable outcome relies on the metal’s durability as well as the speed and clarity of response from the involved agencies.