A planned spacewalk aboard the International Space Station on the evening of Dec. 14 involving cosmonauts Sergey Prokopyev and Dmitri Petelin was canceled due to a coolant leak aboard the Soyuz MS-22 spacecraft.
The leak began around 7:45 PM EST on Dec. 14 (00:45 UTC on Dec. 15) when controllers in both Houston and Moscow noticed a visible leak coming from the instrument module on the Soyuz MS-22 spacecraft. Teams also received an indication noting low pressure in the coolant loop aboard Soyuz MS-22.
At the beginning of NASA TV coverage of the spacewalk around 9:00 PM EST, the leak had become increasingly visible on station cameras, with frozen coolant streaming out of the Soyuz MS-22 instrument module. The leak would continue to go on for at least the next few hours.
During the initial stages of the leak, both Prokopyev and Petelin, suited up inside their Orlan spacesuits, were completing preparations inside the Poisk module for the planned Russian EVA-56 spacewalk. At the time, the Poisk module was depressurizing for the subsequent planned exterior hatch opening.
The event played out during NASA TV’s planned coverage of the spacewalk, with NASA’s Public Affairs Officer Rob Navias commentating.
Problem with Soyuz MS-22 on the ISS right now! pic.twitter.com/V4Ymvnn2D1
— Chris Bergin – NSF (@NASASpaceflight) December 15, 2022
The spacewalk was eventually called off around 9:45 PM EST after mission managers in Star City, Russia, located near Moscow, concluded that the situation was not acceptable for the evening’s event aboard the Russian Orbital Segment (ROS) on the ISS.
Soon after the leak was discovered, NASA released the following statement: “During preparations for this evening’s planned spacewalk by Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin, ground teams noticed significant leaking of an unknown substance from the aft portion of the Soyuz MS-22 spacecraft docked to the Rassvet module on the International Space Station. The spacewalk has been canceled, and ground teams in Moscow are evaluating the nature of the fluid and potential impacts on the integrity of the Soyuz spacecraft, which carried Prokopyev, Petelin, and NASA astronaut Frank Rubio into space after launching from the Baikonur Cosmodrome in Kazakhstan on Sept. 21.”
By around 11:35 PM EST, the European Robotic Arm, located on the Nauka Multipurpose Laboratory Module, was commanded by Russian cosmonaut Anna Kikina to move near the anomaly aboard the Soyuz spacecraft using a camera on the arm. This gave teams on the ground the ability to inspect the issue closely.
Soyuz MS-22 launched to the ISS carrying Sergey Prokopyev and Dmitri Petelin, along with NASA astronaut Frank Rubio, on Sept. 21 from Site 31/6 at the Baikonur Cosmodrome in Kazakhstan. It is currently docked at the nadir port on the Rassvet module. Soyuz MS-22’s planned return is scheduled for March 2023.
The next crewed Russian spacecraft, Soyuz MS-23, is also scheduled to launch to the ISS in March of 2023.
The concern now around Soyuz MS-22 turns to the “lifeboat” role that every crewed spacecraft has aboard the Station, which is the ability to haul each crew member back to earth in the case of a rapid emergency. It is unknown at the moment how flyable Soyuz MS-22 is given the leak.
This event occurs as the Space Station is in a high beta angle, meaning the station is in constant sunlight lasting five days. This period began on Dec. 10 and will end today, Dec. 15 at 19:10 UTC. These high beta angles happen a couple of times a year.
The planned spacewalk time was unusual for it being during the overnight hours, whereas most US and Russian spacewalks occur during the daytime. This alternative time was chosen so that Russian ground station coverage would be available during the planned spacewalk time overnight between Dec. 14 and Dec. 15 EST.
This is yet another postponement of Russian EVA-56, which was originally scheduled for Nov. 25 but was canceled after coolant pump issues were discovered in the Orlan spacesuits of both cosmonauts.
This long-awaited spacewalk would have seen Prokopyev and Petelin remove a radiator from its stowed position on the side of the Rassvet module and its subsequent relocation on the forward-facing side of the Nauka module.
The official name for the Rassvet module is the Russian Rassvet Mini-Research Module-1 (MRM-1).
The radiator has been stowed aboard Rassvet since its integration with the module inside the Astrotech Space Operations Facility in Titusville, Florida, following its arrival from Russia in Dec. 2009.
Following this, the Rassvet module was moved to the Orbiter Processing Facility at NASA’s Kennedy Space Center where it was lowered into the payload bay of Space Shuttle Atlantis. It would subsequently launch aboard Atlantis on May 14, 2010, from Launch Complex 39A on the STS-132 mission.
At the time, STS-132 was planned to be the last mission for Atlantis before the orbiter would be needed for an additional mission, that being STS-135.
(Lead image: Suspected coolant is seen leaking from the instrument and propulsion module aboard Soyuz MS-22 on Dec. 14. Credit: NASA)