The US national space agency, NASA, said it was too early to draw any conclusions on causes of August’s air leak from the International Space Station before samples obtained during a Russian spacewalk are examined on the ground.

Axar.az reports citing TASS.

"Today’s Russian spacewalk with cosmonauts Oleg Kononenko and Sergey Prokopyev was conducted to inspect and collect samples and photograph the surface of the Soyuz MS-09 Habitation Module. The spacewalk was strictly designed to gather additional engineering data for Russian specialists on Earth for future analysis of potential causes for the source of the leak," NASA spokesperson Cheryl Warner told TASS. "It will take time for the analysis of the material returned from the spacewalk to be completed."

"As visual indications alone are not sufficient to draw major conclusions, it would not be appropriate to speculate on results from the spacewalk until the ground analysis is complete," she added.

Russian cosmonauts Oleg Kononenko and Sergei Prokofyev were expected to spend six hours and 31 minutes in space but completed their spacewalk more than an hour behind schedule.

The spacewalk’s main task was to inspect the hole on the external surface of the habitation module of the Soyuz MS-09 spacecraft, which led to a drop in air pressure on board the International Space Station on August 30. The Russian cosmonauts’ unsealed thermal insulation and the meteorite shield in the spot determined by the crew as lacking air tightness and examined the area for signs of sealant.

The hole had to be examined in space, because it is located in the section of the spacecraft that would separate during the reentry and burn in the atmosphere, making a further investigation impossible.

It was the first time in the history of cosmonautics when the meteorite shield was opened during a space flight.