Air leak in Russian section of ISS continues

Dmitri Rogozon, the head of Roscosmos, yesterday announced that they will be sending to ISS special equipment for investigating a new air leak in the Russia section of ISS.

This apparently is not the 1-2 inch long crack in the Zvezda module that leaked previously and was found and sealed. Moreover, the article at the link admits that their astronauts found no sign of damage on the outside of Zvezda when they did a space walk in November, suggesting that this first leak was not caused by a micrometeorite hit.

All the known facts so far strongly suggest that the leaks are because of Zvezda’s 20-year-old age, and might be stress fractures caused by the three dozen or so dockings and undockings that have occurred there since its launch.

That the Russians are being so vague about the entire matter reinforces that conclusion. They have never released an image of the first leak, and provided no details about the equipment being sent to the station.

And if Zvezda is beginning to crack due to age, I am not sure what repairs they can do to stop it.

ISS air leak still unlocated

The small air leak that was found on ISS a year ago has still not been located, despite a second weekend where the crew isolated themselves in one module and closed the hatches on all other modules so that ground engineers could track any air supply changes.

At a Sept. 28 briefing about the upcoming Northrop Grumman NG-14 Cygnus cargo mission to the station, a NASA official said that the weekend isolation in the Zvezda module failed to immediately locate the source of the leak. “As of this morning, there was no clear indication of where the leak is,” said Greg Dorth, manager of the ISS Program External Integration Office at NASA. “The teams are still looking at the data and evaluating it.”

This was the second time the ISS crew confined themselves to Zvezda in an effort to track down the leak. A month earlier, the three also spent a weekend in Zvezda with the other modules sealed off in an effort to locate the leak. “After the three days, there was no indication of where the leak was coming from,” Dorth said.

This latest test, he said, featured some “slightly different configurations” in both the U.S. and Russian segments, although he did not elaborate on the differences between the two tests. In addition, Cassidy used an ultrasonic leak detector to see if the leak was coming from Zvezda itself.

These tests were possible since mid-August because there were only three people on station, allowing them to be confined to one module for a period of time. Moreover, during this time no other spacecraft have arrived or left. It is suspected that the leak is most likely coming from the connection point between two modules, and adding or removing a Soyuz, Dragon, or freighter to the station shifts its center of gravity, changing the stress points at those connections.