MOSCOW, August 31. /TASS/. The pressure on the International Space Station (ISS), after Russian cosmonauts covered a micro-fracture with sealant on the Soyuz MS-09 spacecraft, remains stable and no new leaks have been spotted, Russia’s State Space Corporation Roscosmos Executive Director for Manned Programs Sergei Krikalyov told TASS on Friday.
"The first layer [of the sealant] is already proving to be completely air tight. At night, tests were held and the pressure was monitored for a lengthy period of time. Right now, the pressure is stable and no further leaks have been detected," the executive stated.
No swelling on the sealant layer used to plug the hole on the Soyuz spacecraft has been identified, he said.
"When the epoxy-based sealer was used [to plug the hole], it was made thicker for more reliability in order to make sure that nothing would swell up there. This is a sort of a sealant with a safety margin," Krikalyov said.
A drop in pressure due to an air leak was detected on the orbital outpost overnight to August 30. Later, the cause was discovered to be a fracture 3-4cm in diameter in the orbital compartment of the manned Soyuz MS-09 space vehicle docked to the space station.
Russia has set up a commission consisting of specialists from Roscosmos, the Energia Rocket and Space Corporation and the Central Research Institute of Machine-Building (TsNIImash, Roscosmos’s major research institute) to investigate the incident.
As a source in the Russian space industry told TASS, the fracture in the Soyuz vehicle could have been caused either by external factors (a micro-meteorite or space debris hitting the ship) or by defects in the spacecraft’s internal casing.
The leak was soon localized and poses no danger to the crew. The Russian cosmonauts had plugged the hole with the sealant and restored pressure aboard the space station by Thursday evening, after which the Mission Control Center outside Moscow gave instructions to suspend works until morning. On Friday, the sealant will be checked for its reliability and a final decision on the situation will be made by the evening of August 31.