Russia's space agency said that the crew of three astronauts stuck on the International Space Station (ISS) because of a leak in their damaged return capsule were to land on Earth in September in a Soyuz MS-23 replacement capsule.

Russian cosmonauts Sergey Prokopyev and Dmitry Petelin and U.S. astronaut Francisco Rubio, who had been due to end their mission in March, were left stuck in space after the cooling system of their Soyuz MS-22 capsule started leaking two months ago.

"(Their return flight) is now scheduled to take place on Soyuz MS-23 in September 2023," Russian space agency Roscosmos said.

It said the Soyuz MS-23 replacement capsule would launch on Feb. 24 and dock with the ISS on Feb. 26. The damaged MS-22 spacecraft will land without a crew in March.

NASA and Roscosmos believe a micrometeoroid caused last year's leak on the MS-22 spacecraft – a tiny particle of space rock hitting the capsule at high velocity.

An external impact is also believed to have caused a separate leak earlier this month on the cooling system of the Progress MS-21 cargo ship, which officials deorbited last week.

Both leaks have caused headaches for Roscosmos and NASA, which have had to rearrange their schedules and postpone planned spacewalks.

"Space missions always carry a huge risk of life-threatening emergencies for astronauts," Roscosmos said. "Micrometeoroid impacts on a spacecraft or orbital station have happened before, but unlike with the Soyuz MS-22, they have never had such serious consequences."

"No country in the world has a surveillance system capable of tracking micrometeoroids of this size – about 1 millimeter."

It said overhauling the Soyuz cooling system would be costly and add weight to the capsule but that it would consider past incidents when developing new spacecraft.