Russian spacewalkers find mystery hole on outside of capsule - but say it did not look drilled

Spacewalking astronauts have found a tiny hole outside of the capsule docked to the International Space Station, saying they don't think it was drilled.

On Tuesday, two Russian astronauts ripped through thick insulation the capsule, looking for clues to a mysterious drilled hole that leaked precious cabin air four months ago.

Sergei Prokopyev and Oleg Kononenko spotted the tiny hole in the external hull of the Soyuz capsule, more than five hours into their gruelling spacewalk.

"That is exactly the hole we've been looking for, guys," radioed Russian Mission Control outside Moscow.

The spacewalkers reported seeing no drill marks around the black dot, like on the inside.

In August this year, the station crew patched the hole in the Soyuz capsule, plugging it with epoxy and gauze. Russian space officials wanted the site surveyed from the outside, before the capsule's return to Earth next week with Mr Prokopyev and two others.

This part of the capsule will be jettisoned as usual before atmospheric re-entry and so poses no risk to descent.

Mr Prokopyev and Mr Kononenko had to use a pair of telescoping booms to reach the Soyuz. It took nearly four hours for them to cross the approximately 100 feet to get to the capsule.

Then the insulation proved harder to remove than expected, taking another one to two hours.

To expose the external hull, Mr Kononenko needed to cut away a 10-inch swatch of thermal insulation and debris shield. Bits of shredded silver insulation floated away as they slashed at it with knives and long cutters.

Mission Control repeatedly urged the spacewalkers to take a few minutes' rest, in their bid to collect samples of the black epoxy sealant protruding from the hole, just one-tenth of an inch across.

The capsule leak caused a flap between the US and Russian space agencies following its discovery.

Russian space chief Dmitry Rogozin observed that the hole could have been drilled during manufacturing - or in orbit.

The space station's commander at the time flatly denied any wrongdoing by himself or his crew. Mr Rogozin has since backpedalled his statement.

A Russian investigation is ongoing, according to Mr Rogozin, and samples collected during the spacewalk will be returned to Earth on the Soyuz.

The spacewalk findings could lead to better repair techniques in the future, officials said.

The Soyuz is scheduled to depart the orbiting lab on December 19, with Mr Prokopyev, American Serena Aunon-Chancellor and German Alexander Gerst, the station's current skipper.

Remaining aboard the 250-mile-high outpost for the next six months will be an American, Russian and Canadian who arrived last week.

Additional reporting by Associated Press.