Russia’s Roscosmos space agency today released dramatic video of the October 11 Soyuz MS-10 launch failure and confirmed that it was caused by a malfunctioning sensor. It also confirmed that the next International Space Station (ISS) crew, Soyuz MS-11, will launch on December 3, earlier than originally planned.

The news that the problem was traced to a sensor malfunction and the next crew could launch on December 3 was revealed yesterday by Sergei Krikalev, Roscosmos executive director for human spaceflight and one of Russia’s most experienced cosmonauts.

At a press conference today, more details were offered by the investigation commission about what happened to the Soyuz-FG rocket that day. It was already known that the problem occurred when the first and second stages separated. Video from an on-board camera shows it happening as the four strap-on boosters detach from the core stage at 1:23. The left booster impacts the core stage moments before the video ends.

Automated systems on the rocket immediately separated the crew capsule, carrying Russian cosmonaut Aleksey Ovchinin and NASA astronaut Nick Hague. They landed safely and are fine, other than disappointed that they are not aboard the ISS. Both are expected to have another chance.

Roscosmos released a graphic with a timeline of events. RussianSpaceWeb.com’s Anatoly Zak translated it into English and it is used here with his permission.

The problem was a separator sensor pin on one of the four strap-ons that had been bent by 6°45′ when the boosters were mated to the core vehicle at the Baikonur Cosmodrome. Consequently the lid of the nozzle intended to separate the booster did not open.

Other Soyuz rockets that already have been assembled at Baikonur will have to be checked, but Roscosmos clearly is optimistic. It will launch a robotic cargo mission to ISS, Progress MS-10, from Baikonur on November 16 which uses a similar version of the Soyuz rocket. That will be one test. Assuming it and two other Soyuz launches from other launch sites in the next few weeks go well, the Soyuz MS-11 mission, with Russian cosmonaut Oleg Kononenko, NASA astronaut Anne McClain, and Canadian astronaut David Saint-Jacques, will launch on December 3.