A planned spacewalk by two Russian cosmonauts aboard the International Space Station has been cancelled after mission controllers noticed “significant leaking” from a docked Soyuz spacecraft.
A “visible stream of flakes” was first observed about 7.45pm EST (12.45am GMT Thursday) prompting Russian flight controllers to abort the mission, a Nasa livestream showed.
“Tonight’s spacewalk has been cancelled because of an observed leak of what is believed to be a cooling substance from the Soyuz MS-22,” Nasa commentator Rob Navias can be heard saying in a broadcast from Nasa’s Johnson Space Center in Houston.
“We noticed a visible steam of flakes coming from the aft of the Soyuz near the instrumentation and propulsion module that was indicative of a leak,” Navias added.
Footage showed a torrent of snowflake-like particles spraying from the rear section of the capsule.
The mishap occurred just before two of the Roscosmos cosmonauts, crew commander Sergey Prokopyev and flight engineer Dimitri Petelin, suited up for a planned spacewalk to move a radiator from one module to another on the Russian segment of the ISS.
An official for Russia’s mission control operations near Moscow was heard telling the pair in a radio transmission that their spacewalk was being cancelled while engineers worked to determine the nature of the problem.
Specialists in Moscow were evaluating the nature of the fluid and what impact it may have on the integrity on the Soyuz spacecraft, a statement from Nasa read.
The space agency said the International Space Station (ISS) crew was not thought to be in any danger.
The spacewalk planned for Wednesday was postponed once before, in late November, due to faulty cooling pumps in the cosmonauts’ spacesuits, Navias said.
Reuters contributed to this report