WASHINGTON — Russia has delayed the launch of an uncrewed Soyuz spacecraft to the International Space Station, intended to replace a damaged spacecraft there, to investigate damage to a second spacecraft there.

In comments posted Feb. 13 on the Telegram social media account of the Russian space agency Roscosmos, Yuri Borisov, head of the agency, said the launch of the Soyuz MS-23 spacecraft that had been scheduled for late Feb. 19 (Feb. 20 at the Baikonur Cosmodrome) would be delayed until early March.

The delay, he said, would give investigators time to study a coolant leak in the Progress MS-21 cargo spacecraft reported Feb. 11. That leak is similar to one that the Soyuz MS-22 spacecraft suffered in December.

The earlier leak led Roscosmos, in conjunction with NASA and other ISS partners, to decide in January to launch Soyuz MS-23 without a crew. It will replace Soyuz MS-22, which will return to Earth without a crew. That will ensure that the crew that flew to the ISS on Soyuz MS-22 — Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin and NASA astronaut Frank Rubio — have a safe means of returning home, but will extend their stay on the ISS by several months.

In January, Roscosmos blamed the Soyuz coolant leak on a micrometeoroid impact, an explanation that NASA publicly accepted then. However, the similar Progress leak has created new doubts about that explanation.

Roscosmos released Feb. 13 an image of damage to the Soyuz MS-22 spacecraft that had a coolant leak in December. The agency said the image was proof that the leak was caused by external damage. Credit: Roscosmos

Roscosmos released Feb. 13 the first close-up image of the location of the Soyuz leak, taken by a camera on the Canadarm2 robotic arm. The image showed a small hole at the center of a discoloration on the white surface of that region of the spacecraft. The images, Roscosmos argued, were proof that the hole was “external damage” to the spacecraft.

Roscosmos said Feb. 14 that a similar inspection would be carried out of the Progress MS-22 leak. The agency didn’t provide additional details about the investigation or the potential cause of the leak.

The delay in Soyuz MS-23’s launch will likely push it back until after a crew exchange on the station. NASA is scheduled to launch the Crew-6 mission to the station Feb. 26. It will deliver to the station NASA astronauts Stephen Bowen and Woody Hoburg, UAE astronaut Sultan Alneyadi and Roscosmos cosmonaut Andrey Fedyaev to the station on a SpaceX Crew Dragon. They will replace NASA’s Nicole Mann and Josh Cassada, JAXA’s Koichi Wakata and Roscosmos’s Anna Kikina, who will return to Earth on the Crew-5 Crew Dragon several days after the Crew-6 arrival.

NASA said Feb. 13 that the crew of the upcoming Crew-6 mission entered pre-launch quarantine Feb. 12, and that launch remained scheduled for Feb. 26.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...