Russian space agency Roscosmos has revealed the cause of the Soyuz MS-10 mishap. During a press conference, the State Commision formed to investigate the mishap found that the failure had been caused by the deformation of a sensor during assembly.
The State Commission was chaired by deputy general director of TsNIImash (a Russian rocket and spacecraft research centre), Oleg Skorobogatov. The rest of the commision was made up of several key individuals from TsNIImas, Roscosmos and the Progress Rocket Space Centre.
According to the commission, during the assembly of the Soyuz FG launch vehicle, a separation contact sensor was deformed during the installation of one of the vehicle’s boosters. The deformation meant that the lid to the nozzle cover of the oxidizer tank on the affected booster failed to open. As a result, the booster underwent an abdominal separation and collided with the central core of the rocket. This led to depressurization and quickly afterwards a loss of stabilization and final total vehicle failure.
In addition to announcing the findings of the State Commission, Roscosmos released onboard footage of the failure. The harrowing last few moments of the video reveal a glimpse of what the crew of the Soyuz MS-10 must have experienced.
The Soyuz MS-10 launched aboard a Soyuz FG rocket from the Baikonur cosmodrome on October 11, 2018. Although the launch initially appeared to be successful, an issue arose during the separation of the four strap-on boosters that forced the Soyuz MS-10 vehicle into a ballistic descent mode. Although the two-member crew were subjected to extreme g-force during their escape from the crippled rocket, both men walked away from the vehicle unharmed.