The space station's crew patched the tiny hole in the Soyuz capsule last August, using epoxy and gauze. While not an immediate risk, they investigated and found a hole on the inside of the Soyuz habitation module, which is now docked at the space station.
The Soyuz capsule is due to transport three of the station's crew back to Earth next Wednesday.
The hole was repaired on the same day restoring the hermetic integrity of the ISS. With Gerst Prokopyev, and the US astronaut Serena Auñón land-Chancellor shortly before Christmas, back on earth.
Initially thought to be the result of a micrometeorite impact, subsequent investigation revealed it to be man made, and Russian Federation launched a full investigation to determine where and when it was created. As NPR reported in September, Russian officials believe the leak "was likely caused by a human hand". This led to speculation that perhaps someone purposefully created the hole, sparking rumors of sabotage. There are traces of a drill sliding along the surface. Investigators quickly dismissed theories of meteorite impacts, as the hole seemed to come from inside the capsule, said Dmitry Rogozin, the head of Russia's space agency Roscosmos, according to state news agency TASS.
Hence the precarious, hours-long spacewalk where one cosmonaut tried to hold the shielding back while the other kept cutting and looking for the hole.
Their goal was to collect samples of any residue found on the habitation module's hull.
To expose the external hull, they cut away a 10-inch (25-centimeter) swatch of thermal insulation and debris shield. Also they took samples of material. The task wasn't easy.
"The active participation of worldwide partners, primarily NASA, in the investigation is not expected, although we have called for a joint investigation and been ready to provide available materials: photos, videos, documents, samples of materials taken during the spacewalk", the source said.
Today, Prokopyev joined Kononenko on a spacewalk to inspect the fix area from the outside in an effort to discover what caused the leak and to collect a sample of the epoxy that had extruded through the hole from the inside. So far, the capsule has remained secure and pressure on board the space station has maintained.