Russian and NASA engineers were assessing a coolant leak from a Soyuz crew capsule docked to the International Space Station (ISS) on Thursday that may have been caused by a micrometeorite strike.
Spectacular NASA television footage showed white snowflake-like particles billowing from the back of the craft for hours.
The refrigerant leak forced the last-minute cancellation of a spacewalk by two Russian cosmonauts on Wednesday and could affect a return flight to Earth for three crew members.
The Russian space corporation Roscosmos and the US space agency said the leak from the Soyuz MS-22 spacecraft posed no danger to astronauts and cosmonauts aboard the ISS.
“Crew members aboard the space station are safe and were not harmed during the leak,” NASA said.
He said ground teams were assessing “potential impacts on the integrity of the Soyuz spacecraft.”
“NASA and Roscosmos will continue to work together to determine the next course of action,” NASA said.
TASS news agency quoted Sergei Krikalev, a former cosmonaut who heads the manned spaceflight program for Roscosmos, as saying the leak could have been caused by a tiny meteorite that hit Soyuz MS-22.
“The cause of the leak may be a micrometeorite entering the radiator,” TASS quoted Krikalev as saying. “The possible consequences are changes in the temperature regime.”
“No other changes in the telemetry parameters of the Soyuz spacecraft or the station (ISS) have been detected in the Russian or American segments,” Krikalev said.
Coolant pressure drop
NASA later added that the station’s crew “completed normal operations Thursday, including … setting up instruments ahead of a planned spacewalk in the United States on Monday.”
Soyuz MS-22 carried Russian cosmonauts Sergei Prokopyev and Dmitry Petelin and NASA astronaut Frank Rubio to the ISS in September.
They are scheduled to be returned to Earth in March, and another ship would have to be sent to the ISS if Soyuz MS-22 is not available.
Prokopyev and Petelin were making preparations for a spacewalk on Wednesday when the leak was discovered.
“The crew reported that the warning device in the ship’s diagnostic system went off, indicating a pressure drop in the cooling system,” Roscosmos said. “At this time, all systems of the ISS and the ship are operating normally, the crew is safe.”
NASA said the leak had occurred in the “rear end” of Soyuz MS-22, which is secured to the space station.
There are currently four other astronauts and cosmonauts aboard the space station in addition to Rubio, Prokopyev and Petelin.
NASA astronauts Josh Cassada and Nicole Mann, Japanese astronaut Koichi Wakata and Russian cosmonaut Anna Kikina were transferred to the ISS in October aboard a SpaceX spacecraft.
Space has been a rare avenue of cooperation between Moscow and Washington since the start of Moscow’s assault on Ukraine in February and subsequent Western sanctions on Russia that severed ties between the two countries.
The ISS was launched in 1998 at a time of increased cooperation between the US and Russia following their Cold War space race competition.