No one is certain. The best guess is that the seals on the hatch leading to the PrK module are, in some way, leaking. In this scenario, pressure from the station is feeding the leak inside the PrK module through these seals, leading to a stable pressure inside—making it appear as though the PrK module leaks are fully repaired.
At this point, NASA is monitoring the ongoing leak and preparing for any possibility. A senior industry source told Ars that the NASA leadership of the space station program is “worried” about the leak and its implications.
This is one reason the space agency delayed the launch of a commercial mission carrying four astronauts to the space station, Axiom-4, on Thursday.
“The postponement of Axiom Mission 4 provides additional time for NASA and Roscosmos to evaluate the situation and determine whether any additional troubleshooting is necessary,” NASA said in a statement. “A new launch date for the fourth private astronaut mission will be provided once available.”
One source indicated that the new tentative launch date is now June 18. However, this will depend on whatever resolution there is to the leak issue.
What’s the worst that could happen?
The worst-case scenario for the space station is that the ongoing leaks are a harbinger of a phenomenon known as “high cycle fatigue,” which affects metal, including aluminum. Consider that if you bend a metal clothes hanger once, it bends. But if you bend it back and forth multiple times, it will snap. This is because, as the metal fatigues, it hardens and eventually snaps. This happens suddenly and without warning, as was the case with an Aloha Airlines flight in 1988.
The concern is that some of these metal structures on board the station could fail quickly and catastrophically. Accordingly, in its previous assessments, NASA has classified the structural cracking issue on the space station as the highest level of concern on its 5v5 risk matrix to gauge the likelihood and severity of risks to the space station.
In the meantime, the space agency has not been forthcoming with any additional information. Despite many questions from Ars Technica and other publications, NASA has not scheduled a press conference or said anything else publicly about the leaks beyond stating, “The crew aboard the International Space Station is safely conducting normal operations.”
