According to Russian media reports, the Russian Space Agency (Roscosmos) believes that last week's air leak aboard the International Space Station (ISS) was more likely due to human error than the impact of a micrometeorite. The claim is that the 2 mm hole in the Soyuz TMA capsule MS-09 may have been the result of an inept worker back on Earth who tried to cover up for accidentally drilling a hole in the wrong place.

On August 30, mission control detected a fall in pressure aboard the ISS due to some unknown leak. Following emergency procedures, the six members of the station crew managed to isolate the leak, which was behind a decorative sheet next to the toilet in the Orbital Module section of the Soyuz spacecraft. Once it was found, the hole was temporarily covered with a piece of tape until a Russian cosmonaut was able to seal the fracture using a patch of gauze covered with epoxy resin.

The Russian government immediately established a commission to look into the incident. The initial theory was that the Soyuz had been struck by a micrometeorite that penetrated the metal hull of the module. However, reports by the TASS news service and RIA Novosti citing unnamed sources claimed yesterday that Roscosmos has rejected the theory on the grounds that images allegedly returned by NASA showed that the damage came from inside the craft.

The anonymous sources and a statement by Roscosmos head Dmitry Rogozin now assert the most likely scenario is that a worker at RSC Energia, where the Soyuz is built, accidentally drilled a hole in the Orbital Module. Instead of reporting the fault, the worker apparently sealed the hole with glue, which later dried in the vacuum of space and was blown out by cabin pressure. The sources say that traces of unmarked glue were seen by the astronauts during repairs as well as a scratch that could have been caused by a drill slipping.

"We are considering all the theories," says Rogozin. "The one about a meteorite impact has been rejected because the spaceship's hull was evidently impacted from inside. However it is too early to say definitely what happened. But, it seems to be done by a faltering hand … it is a technological error by a specialist. It was done by a human hand – there are traces of a drill sliding along the surface. We don't reject any theories."

We contacted NASA by telephone about the Russian reports. A spokeswoman said that the Russians are handling the incident and that the space agency could neither confirm or deny that validity of the reports.

View gallery - 2 images