Unpiloted Soyuz sendoff from the International Space Station – a compromised craft due to a coolant leak.
Image credit: NASA
An unpiloted Russian Soyuz MS-22 spacecraft is set to return to Earth next week, a craft that was compromised due to a coolant leak late last year.
Departing the International Space Station (ISS), the spacecraft will depart the Rassvet module at 5:57 a.m. EDT, heading for an automated, parachute-assisted landing in Kazakhstan at 7:45 a.m. (5:45 p.m. Kazakhstan time) on Tuesday, March 28.
To replace the damaged Soyuz MS-22 – and help boost the safety of onboard ISS crews — the Soyuz MS-23 “rescue” spacecraft moored to the ISS last month. The fresh Soyuz is to be used to return cosmonauts and an astronaut later this year.
Soyuz MS-22 coolant leak image from last December.
Image credit: NASA
NASA astronaut Frank Rubio and Roscosmos cosmonauts Sergey Prokopyev and Dmitri Petelin launched aboard the Soyuz MS-22 in September 2022. Following an external coolant leak detected on that craft last December, the replacement Soyuz MS-23 was launched to the space station on February 23 of this year.
Onboard cargo
Tucked into the returning, auto-piloted Soyuz MS-22 is over 480 pounds (218 kilograms) of cargo, including the results of scientific experiments (“Neuroimmunity”, “Biomag-M”, “Photobioreactor”, “3D-printer” and others), according to a Roscosmos Telegram posting.
Equipment for analysis or reuse, including navigation modules, lamps, television cameras, and a rechargeable battery, will descend under parachute, as will a charger and backup pumps “Orlanov-MKS”, sleeves of the suit “Orlan-MK”, gas masks, water and condensate samples.
In-orbit inspection of Soyuz MS-22 spacecraft.
Image credit: Roscosmos
“The equipment of the Soyuz MS spacecraft and the equipment of broadband communication systems, control of the onboard equipment and the onboard complex, air conditioning, regeneration of water from urine and oxygen supply are also being returned,” the posting adds.
Coolant-leak cause
Back on December 15, 2022, the external contour of the radiator of the thermal control system of the Soyuz MS-22 spacecraft was depressurized. Specialists later determined that the damage was purportedly caused by a micrometeoroid impact.
The vehicle’s radiator pipeline spewed its coolant out into space, compromising the overall integrity of the craft to return crew members safe and sound to Earth by keeping the interior of the Soyuz in a comfy temperature range.
Image credit: Roscosmos
Image credit: Roscosmos/RSC Energia
As for the cause of the coolant loss, studies aided by robotic arm-mounted cameras were carried out. Up-close looks found a tiny hole in the Soyuz MS-22 radiator less than 1 millimeter in size, created by an impactor careening through space at a speed of 7,000 meters per second, according to Russian space specialists.
Reentry process
In bringing back the Soyuz MS-22 descent vehicle, that process entails discarding the troubled instrument-assembly compartment of the ship – so it cannot be evaluated by hands-on experts here on Earth.
The three major components of the Soyuz are the spherical-shaped orbital module, the bell-shaped descent vehicle and the cylindrical-shaped instrument assembly module from which solar panels protrude.
Like the orbital module, the intermediate section of the instrumentation/propulsion module separates from the Soyuz descent module after the final deorbit maneuver and “burns up” in Earth’s atmosphere upon reentry.
Image credit: NASA
