The space station's crew patched the tiny hole in the Soyuz capsule last August, using epoxy and gauze. The agency says it will be coordinating with NASA and others involved in the ISS program to discuss the results.
The Russians needed to cut away the outer layers of the capsule in order to find the hole.
George Washington University space policy expert John Logsdon told NPR in September that there is "a kind of generalized concern about the decline of quality control in Russian space industry in recent years". It will be brought back to Earth and investigated for clues to the cause of a small hole in the Soyuz capsule.
The Soyuz spacecraft is used to ferry astronauts to and from the ISS.
The piece in question contained the mysterious drill hole identified in August as the source of an air leak and will be analyzed 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.
Back when the hole was discovered, Russian MP and former cosmonaut Maxim Surayev suggested that the hole could have been drilled by someone who wanted to return home, although that that would have been a "really low" method. This led to speculation that perhaps someone purposefully created the hole, sparking rumors of sabotage.
Rogozin called the spacewalk "unprecedented in its complexity" on Twitter and Roscosmos said it would "enter the history of space exploration".
For the cosmonauts Oleg Kononenko and Sergei Prokopyev, it was a test of nerves.
To expose the external hull, they cut away a 10-inch (25-centimeter) swatch of thermal insulation and debris shield. Luckily, the cosmonauts discovered the hole was not a major threat to the space station's integrity: it only took a little sealant and tape to fix. Also they took samples of material.
The spacewalkers' job was to collect samples of any epoxy sealant that may have protruded from the hole.
And because this particular module of the capsule will split off and burn up on re-entry back to Earth, they wanted to analyse their fix job from the outside and scrape off some samples of the epoxy to return to Earth and study.