RUSSIA: Russian space agency Roscosmos will launch an uncrewed spacecraft, Soyuz MS-23, to the International Space Station to serve as a return vehicle for cosmonauts Sergey Prokopyev and Dmitri Petelin and NASA astronaut Frank Rubio after the vehicle in which they launched in September sustained damage in space.

The spacecraft they launched in, MS-22, experienced an external coolant leak while docked outside of the IS on December 14. MS-22 will undock without a crew and return to Earth, landing in Kazakhstan about a week or two after the new spacecraft arrives. Soyuz MS-23 is expected to launch to the space station on February 20. Some equipment, survival gear and personal belongings will be shifted from MS-22 to MS-23 while both are at the space station, said Sergei Krikalev, Human Space Flight Programs executive director at Roscosmos. When the MS-22 leak first occurred, pressure sensors inside the spacecraft’s cooling loop showed low readings and coolant was seen leaking into space.

The issue was discovered just before a Russian spacewalk was expected to take place outside of the space station, and the spacewalk was postponed indefinitely. 

Since the leak, NASA and Roscosmos have worked together on collecting imagery and analyzing the Soyuz spacecraft systems.

They determined the MS-22 spacecraft was not safe enough to transport crew back to the ground, in part because the issue with the cooling system could leave the cabin too hot and humid, according to Joel Montalbano, International Space Station program manager at NASA’s Johnson Space Center in Houston.
The commission working on the analysis has concluded that the damage to the Soyuz radiator’s pipeline was caused by a micrometeorid impact, which created a hole with a diameter less than 1 millimeter, according to Roscosmos.

Krikalev said Roscosmos was able to pinpoint the root cause by analyzing photos of the damage and conducting experiments on the ground, such as firing a “high velocity gun” at an aluminum plate to simulate the damage. “Our results of this test completely coincide with our calculation,” he said.