A planned Russian spacewalk was canceled when ground teams noticed a large leak in the Soyuz MS-22 craft docked to the International Space Station.
Cosmonauts Sergey Prokopyev and Dmitri Petelin were all dressed up (in spacesuits) with nowhere to go Wednesday when they were told to stand by as the leak was investigated. The spacewalk was ultimately called off shortly before 10 p.m. ET.
For the first of two scheduled spacewalks outside the ISS, Commander Prokopyev and flight engineer Petelin were set to spend about seven hours transferring a radiator from the Rassvet (Russian for "dawn") module to the Multipurpose Laboratory Module (MLM), known as Nauka (Russian for "science"), with flight engineer Anna Kikina operating the European Robotic Arm.
The pair spent all week preparing for the twelfth ISS spacewalk of the year only to be scuppered at the last moment due to an unknown substance pouring out of the aft portion of the Soyuz MS-22, which carried Prokopyev, Petelin, and NASA astronaut Frank Rubio into space in September.
As of Thursday, ground teams at Mission Control in Moscow continue assessing the leak, evaluating the fluid and potential impacts to the integrity of the Soyuz spacecraft. "NASA and Roscosmos will continue to work together to determine the next course of action following the ongoing analysis," NASA says. "The crew members aboard the space station are safe, and were not in any danger during the leak."
It's unclear whether the Soyuz leak will affect NASA flight engineers Josh Cassada and Rubio's upcoming spacewalk, scheduled for Monday, Dec. 19, to install a second roll-out solar array.