The Soyuz-FG rocket carrying the crewed Soyuz MS-10 spacecraft which which was launched at 0840 GMT on 11 October 2018 from the Baikonur launch site near Tyuratam in Kazakhstan has suffered a fault during its climb into orbit and has not achieved orbital velocity.   The cause of the failure is believed to be in the core second stage which apparently underperformed after separation from the booster/first stages.  While fitted for three, only two crew were on this mission as part of a new Russian policy to lower its space station crew numbers. Two man crew were Cosmonaut Aleksey Ovchinin and NASA Astronaut Nick Hague. Both safely landed after making an emergency escape landing. The spacecraft had been due to dock with the International Space Station (ISS) six hours after launch.

The crew are thought to have used the escape rocket system once it became clear via an internal angular velocity deviation warning that the rocket would not achieve orbital velocity and the capsule and crew have now parachuted safely to Earth in Kazakhstan, 20km east of the town of Dzhezkazgan. The crew suffered significant 6-7 g deceleration loads as during the initial part of their emergency ballistic/suborbital trajectory back to Earth.  Helicopter rescue services are now on their way to the badly shaken crew.  If the crew had stayed on the rocket, it would have come back to Earth but possibly in a location several thousand kilometres down range – possibly in an ocean splashdown which would have been far higher risk.

A full investigation into the failure is now taking place. Unconfirmed reports appear to indicate that one of the four “first stage” booster failed to separate fully and struck into the core second stage causing a rupture and visible debris. While each first stage booster is held in place via its own thrust pushing into a cone, once this thrust is ended and the booster starts to fall away, in order to prevent just such a strike, a valve is released so that 45 degree canted nozzle vents oxidiser propellant to provide a small amount of thrust to push the booster away from the second stage/core stage.  Investigations are now concentrating on the failure of a valve which prevented the “push away” venting of this oxidiser. While all Soyuz launch vehicles are “grounded” for now, the investigation will likely be processed as and any correction applied fast as practically possible allowing flights to resume relatively quickly.

Apart from the four first stage boosters and core stage, debris appears to be visible in this shot of the Soyuz FG launch of Soyuz MS-10. Courtesy: Roscosmos via NASA TV

The escape element of the failure has echos of the Soyuz-18 mission in 1975 when the crew had to make a similar emergency use of the escape rocket during an in flight emergency. This event is the first launch failure of the -FG variant of the Soyuz rocket in 68 launches.  The escape rocket system was also used in the prelaunch explosion of the Soyuz T-10 mission in 1983.

On the ISS, ESA astronaut Alexander Gerst managed to image the moment the Soyuz escape system fired. Courtesy: ESA/Alexander Gerst

The rocket and Soyuz spacecraft itself are insured under a “delivery to the ISS” contract for circa US$71 million.

Comment by David Todd:  After a “depressurising”  hole was found on Soyuz MS-07 which is thought to have been accidentally drilled through during manufacture, and after this launch failure, serious questions are being asked about the safety and quality control of Russian space hardware.