Spacewalking astronauts ripped through thick insulation on a capsule docked to the International Space Station on Tuesday, looking for clues to a mysterious drilled hole that leaked precious cabin air four months ago.
Russians 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.
The “eureka” moment. Spacewalkers find the “small black dot” where controllers believe the area of the fixed pressure leak is located on the Soyuz crew vehicle. #AskNASA | https://t.co/yuOTrYN8CV pic.twitter.com/NFNOIPTkW1
— Intl. Space Station (@Space_Station) December 11, 2018
Back in August, 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 for 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.
And another spectacular shot of spacewalker Oleg Kononenko working outside the Soyuz orbital module preparing to begin inspection work as the Earth passes below. #AskNASA | https://t.co/yuOTrYN8CV pic.twitter.com/N2RnfETpIV
— Intl. Space Station (@Space_Station) December 11, 2018
Then the insulation proved harder to remove than expected, taking another one to two hours of effort.
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 like confetti, as the two slashed at it with a knife 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 at the end of August.
Today’s Russian spacewalk started at 10:59 a.m. EST to inspect the Soyuz crew vehicle. #AskNASA | https://t.co/CNU3J0sWi6 pic.twitter.com/25V4QEYuCB
— Intl. Space Station (@Space_Station) December 11, 2018
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, blaming the news media for twisting his words.
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, US time, with Mr Prokopyev, American Serena Aunon-Chancellor and German Alexander Gerst, the station’s current skipper.
It ferried them up in June.
Remaining aboard the 250-mile-high outpost for the next six months will be an American, Russian and Canadian who arrived last week.
