The Roscosmos Soyuz MS-22/ISS-68S spacecraft undocked from the International Space Station (ISS) Rassvet module at 0957 GMT on 28 March in preparation for an automated landing in Kazakhstan. The uncrewed craft performed a re-entry burn 55 minutes after undocking and successfully re-entered and landed at 1142 GMT, less than two hours after undocking from the ISS.
Soyuz MS-22 returns. Courtesy: Roscosmos.
Soyuz MS-22, which was launched on 21 September 2022, was deemed unsafe for the crew it carried to orbit to return in after it developed a coolant leak in December while docked to the ISS. As a result, an uncrewed Soyuz (Soyuz MS-23) was launched to the ISS on 26 February to allow Sergey Prokopyev, Dmitriy Petelin and Frank Rubio a safe means of return – albeit after a six-month extension to their stay.
Photographic evidence implied at the time that a meteoroid strike had caused the leak to the radiator. A subsequent thermal analysis found that the crew – if they had used Soyuz MS-22 to re-enter – could have just about safely returned, but they would have been very uncomfortable as internal temperatures reached 50 degrees Celsius. ISS Expedition 69 commenced with the departure of Soyuz MS-22.
Engineers can now study the Soyuz MS-22 capsule on the ground to determine why it leaked coolant. The Progress MS-21 freighter, which docked with the ISS in October, also sprang a leak in its external cooling radiator in February and there is concern that there may be an inherent design or quality-control fault in the Soyuz/Progress family.
Soyuz MS-22 was loaded with 218 kg of science experiments, cameras and electronic equipment prior to undocking. The crew of Soyuz MS-22 will now return to Earth in Soyuz MS-23 in September.
