A Russian Soyuz crew ship docked to the International Space Station spewed particles of an unknown substance, possibly coolant fluid, into space on Wednesday night, forcing two Russian astronauts to abort a planned spacewalk as Engineers on the ground scrambled to determine the source and effects of the leak.
Mission controllers first noticed the leak around 7:45 p.m. EST Wednesday (0045 GMT Thursday), according to NASA spokesman Rob Navias, who provided commentary on NASA TV. The leak occurred as Russian cosmonauts Sergei Prokopyev and Dmitry Petelin prepared for a spacewalk to help transfer a radiator from the outside of the Russian Rasovet module to the science module on the space station.
But before the astronauts could eject, Russian ground controllers near Moscow “observed leakage of an unknown substance from the rear of the Soyuz MS-22 spacecraft,” NASA said in a brief statement. Wednesday night
Navias said Russian ground teams heard a warning tone indicating a drop in pressure in the outer cooling loop on the Soyuz spacecraft when the particles were first seen moving away from the capsule.
Navis said the Soyuz spacecraft’s single cooling loop has two folds. It was not immediately clear what impact the apparent coolant leak might have on the performance of the Soyuz spacecraft, which launched Sept. 21 from the Baikonur Cosmodrome in Kazakhstan with Prokopyev, Petelin and NASA astronaut Frank Rubio on board.
“The spacewalk has been cancelled, and ground teams in Moscow are evaluating the nature of the fluid and the potential implications for the integrity of the Soyuz spacecraft,” NASA said in a statement.
Russian engineers were also assessing whether the leak could have been caused by an impact of space junk or a micrometeoroid, or whether it could have been triggered by a problem on the Soyuz spacecraft.
The Soyuz MS-22 spacecraft is scheduled to return to Earth in late March with Prokopyev, Petelin and Rubio on board. Until then, the spacecraft serves as an emergency lifeboat for the three-member crew that launched it in September. If Russian officials determine that the Soyuz is unable to bring the MS-22 spacecraft crew home, a replacement Soyuz can be launched from Baikonur without anyone on-board to automatically dock with the station. .
But it is unclear when the next in the Soyuz line, Soyuz MS-23, might be ready for launch. It is currently scheduled to fly on March 16 with Russian cosmonauts Oleg Kononenko, Nikolai Chubb and NASA astronaut Loral O’Hara on board to begin a six-month campaign.
Russian ground controllers instructed cosmonauts on the Russian section of the station to take zoomed-in photos of the instruments and propulsion module on the Soyuz MS-22 spacecraft, the apparent origin of the leak.
There are currently seven crew members aboard the International Space Station. A SpaceX Crew Dragon spacecraft is also docked in the US section of the outpost after arriving on October 6 with NASA astronauts Nicole Mann, Josh Cassada, Japanese astronaut Koichi Wakata and Russian cosmonaut Anna Kikina.
Two Russian Progress resupply ships and a Northrop Grumman Cygnus cargo freighter are also attached to the space station.
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