With more than two decades behind it, the International Space Station inevitably suffers from regular air leakage. This is not serious, but in recent months engineers have detected a higher than usual rate of leakage. The challenge now is to find where that leak is occurring, and it’s not going to be easy.
The leak was first noticed in September 2019 and it’s not the first to be found. In 2018 for example they found one in the Soyuz MS-09 (attached to the ISS) which was later repaired. Now another leak seems to be causing air loss again at the station. This is not particularly serious, although it is enough to take it into account and try to repair it in time.
This is going to be the method of NASA and the other partners of the International Space Station to end the problem. In order to stop the leak, the first step is to isolate each part of the station separately to see where air is being lost. This means monitoring each module separately and closing them off from each other. Hence, during this last weekend the current station crew has been confined to the Zvezda module. This allows the engineers to calmly analyze each of the other modules by closing all the hatches.
It is hoped that this will at least help to pinpoint where the problem lies and then make it easier to find the leak. If the module that is releasing more air than normal is found, the astronauts will then search for and identify the leak specifically. Finally, depending on the problem, the astronauts will try to repair the leak as they did in 2018.
NASA indicated that this process does not pose any risk to the crew. Currently made up of three astronauts, they have spent the last few days since Friday, August 21, confined to a single module while searching for the problem. They also have access to two more modules if needed.
Regarding the reason of the leak, it can be for dozens of things really. One of the most likely possibilities is that some micrometeorite has caused a fracture. This is in fact what was thought to have happened in 2018, although finally Roscosmos (the Russian space agency) identified the problem as human error during the construction of Soyuz, even pointing to possible sabotage.