The Soyuz MS-22 spacecraft recently made history by becoming the first Soyuz vehicle to undock from the International Space Station (ISS) without any crew aboard. The vehicle had returned to Earth with empty seats due to a significant coolant leak it experienced last December. The incident had resulted in a large amount of liquid spilling out of the spacecraft, which at the time was docked at the ISS. It was deemed too risky to use the Soyuz capsule to bring home three crewmembers in case its interior heated up to a dangerous level as it entered Earth’s atmosphere at high speed. Putin signed the law allowing Russia to leave the ISS by mid-2020s.
Roscosmos, which operates the Soyuz spacecraft, was keen to bring the empty vessel back to Earth as it wanted to examine it and determine what caused the leak. Engineers currently suspect that the capsule may have been struck by a micrometeoroid while docked at the station, but analysis is ongoing.
NASA astronaut Frank Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin were the crewmembers originally scheduled to travel back to Earth aboard the Soyuz MS-22. They remain aboard the ISS, with their mission extended by six months due to the lack of spacecraft to bring them home. In February, Roscosmos sent up an empty replacement Soyuz capsule, which is currently docked at the space station. The three crewmembers are now scheduled to return home aboard the Soyuz MS-23 in September 2021 instead of this month.
The successful return of the Soyuz MS-22 without incident is a testament to the reliability of the Soyuz spacecraft, which has been used for manned space flight by the Soviet/Russian space agencies for more than 50 years. However, the incident highlights the importance of contingency planning and redundancy in manned space flight programs. It also underscores the need for continued investment in new manned spacecraft, such as NASA’s Commercial Crew Program, which aims to provide alternate means of transporting astronauts to and from the ISS.