MOSCOW, October 28. /TASS/. The air leakage place discovered aboard the International Space Station (ISS) looks more like a scratch 2-3 cm long, Cosmonaut Anatoly Ivanishin said at a post-flight press conference on Wednesday.

"What we see is what I would describe as a scratch. I am not inclined to use the word ‘crack’ because we cannot look deep into the metal’s structure. This scratch is several centimeters long, about 2-3 cm," the cosmonaut said.

The scratch is curvilinear, he added.

A source told TASS in August that the space station’s Russian-American crew was working on tracing an air leak aboard the orbital outpost. Later, Russia’s State Space Corporation Roscosmos confirmed this information.

The ISS crew reported to Russia’s Flight Control Center on the morning of October 15 that the cosmonauts had found the possible air leak spot in the inter-section compartment of the Zvezda module with the help of a tea bag. As the cosmonauts said, the air was possibly leaking through a fracture. The crack was no more than 4 cm wide and posed no threat to the space station’s safety, Roscosmos specified.

The air leak spot has now been sealed with temporary means. Meanwhile, a source in the space industry told TASS that the air leak would be fully eliminated after the Soyuz MS-16 spacecraft’s landing. As the source explained, this measure was required to make some measurements with the closed hatches.

Air leak spotted by cosmonaut Vagner

The scratch the air is leaking through aboard the ISS was spotted by cosmonaut Ivan Vagner, Ivanishin said.

Tea leaves helped the crew find the air leak spot, he explained.

"We tried this in the evening before closing the hatch and then we opened the hatch and it was only in the evening that my colleague Ivan discovered that a large amount of tea leaves had amassed in a certain place," Ivanishin noted.

When Vagner stirred the tea leaves, those that flew to a distance of over half a centimeter would fly away while those that moved away to a shorter distance would be drawn back. This could be observed for several seconds, the cosmonaut explained.

Later, the ISS crew made an experiment with extra tea, taking photos and video, including close-ups of that particular place, Ivanishin said.

Air leak aboard orbital outpost to be sealed with something 'more serious'

Specialists of Russia’s Energia Space Rocket Corporation are working on how to eliminate the scratch that caused the air leak on the International Space Station, Ivanishin said.

"My understanding is that Energia specialists are working on this problem and do not want to rush. They are working on the systemic solution to this problem. This will not be Kapton tape, this will be something more serious. But it is early to speak about that," the cosmonaut said.

After the cosmonauts plugged the scratch on the ISS with the Kapton tape, the air pressure continued falling aboard the orbital outpost but the air leak rate dropped, Ivanishin said.

Ivanishin and Vagner recently discussed the air leak with their colleagues who had come across the same problem in the habitation module of the Soyuz MS-09 spacecraft. "They told us that when they used the Kapton tape, the ultra-sound detector all the same registered the leakage," Ivanishin noted, stressing that the Kapton tape could not fully seal the air leak but could reduce the pressure drop.

Soyuz MS-16 spacecraft’s landing

The descent capsule of the Soyuz MS-16 manned spacecraft landed in Kazakhstan on the morning of October 22. The re-entry vehicle delivered Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner and NASA astronaut Chris Cassidy back to Earth.

Roscosmos cosmonauts Sergei Ryzhikov and Sergei Kud-Sverchkov and NASA astronaut Kathleen Rubins continue working aboard the ISS.