Russia's space agency said two cosmonauts took samples of the exterior of the International Space Station (ISS) as part of efforts to resolve the mystery of a small hole found in a Soyuz spacecraft docked at the station.
The two Russians performed the space walk on December 11, as part of an effort by Roskosmos to pinpoint the cause of the hole, which was found in August in the capsule and strained relations between the Russian and U.S. space agencies.
The hole, detected in August, caused an air leak on the space station.
А live broadcast shown on NASA's website showed Oleg Kononenko and Sergei Prokopyev trying to cut through insulation of the spacecraft with a knife, in order to find the external part of the hole. The materials will be brought back to Earth for further examination.
The chief of Roskosmos, Dmitry Rogozin, had floated unusual theories, including that an American astronaut purposely made the 2-millimeter hole in order to return to Earth sooner than scheduled.
The American commander who was in charge of the station at the time flatly denied any wrongdoing by himself or his crew.
Rogozin later backpedaled on his statement.
The U.S. space agency NASA, meanwhile, has downplayed the incident over the puncture, which caused a slight drop in oxygen but was quickly sealed,