Roscosmos Identifies Cause of Launch Failure, Sets Dates for Next ISS Flights

Expedition 57 Flight Engineer Alexey Ovchinin of Roscosmos, left, and Flight Engineer Nick Hague of NASA, right. embrace their families after landing at the Krayniy Airport, Thursday, Oct. 11, 2018. (Credit: NASA/Bill Ingalls)

The abort of a crewed Soyuz launch to the International Space Station last month was caused by a damaged sensor pin in a mechanism designed to separate one of the rocket’s four strap-on boosters from the core stage, Roscosmos has announced.

“The abnormal separation was caused by the non-opening of the lid of the nozzle intended to separate a side Block D oxidizer tank due to the deformation of the separation sensor pin,” the space corporation said in a press release. “It was damaged during the assembling of the strap-on boosters with the core stage (the Packet) at the Baikonur Cosmodrome. The LV [launch vehicle] failure cause is of the operational nature and spreads to the stock of already assembled packets of the Soyuz rocket.”

Oleg Skorobogatov, who headed up the investigation, said at a press conference that the nose of the strap-on booster hit the core stage in the area of the fuel tank, resulting in a decompression that triggered the abort. Skorobogatov is deputy director general of TsNIImash.

Russian cosmonaut Alexey Ovchinin and NASA astronaut Nick Hague landed safely under parachute in their MS-10 Soyuz spacecraft. Neither one was injured.

“The Emergency Crew Rescue System of Soyuz MS-10 spaceship functioned properly,” Roscosmos said in its press statement. “The crew was acting as required by the on-board instructions and those given by the Mission Control Center.”

Roscosmos has taken steps to prevent a recurrence of the incident and approved a plan to resume launches to the space station.

“The State Committee has approved the launch dates under the International Space Station Program as follows: the launch of Soyuz-FG rocket with Progress MS −10 cargo spaceship to go on November 16, 2018, and the launch of Soyuz MS-11 manned spaceship to go on December 3, 2018. The crew of Soyuz MS-09 — Alexander Gerst (ESA), Sergey Prokopiev (Roscosmos) and Serina Auñón-Chensellor (NASA) — will return to the Earth on December 20, 2018,” the corporation said.