The launch failure last month of a manned mission to space was caused by a faulty sensor that was damaged during the Soyuz rocket's assembly at the launch center in Kazakhstan, the head of a Russian commission investigating the incident has said.
"The cause of the nonstandard separation" of the rocket's second stage was a "deformation" of a part during assembly at the Baikonur Cosmodrome, Oleg Skorobogatov said.
He said this caused a booster rocket from the first stage to malfunction and hit a fuel tank, which "led to the loss of stabilization" and triggered an emergency landing.
The executive director of Russia's Roskosmos space agency, Sergei Krikalyov, said on October 31 that the root of the problem was a sensor that indicated the separation of the first two stages of the Soyuz rocket.
Skorobogatov, who heads TsNIIMash, a Russian spacecraft and missile-development agency, said the commission ruled out that the problem happened at the sensor-production facility.
In the aborted October 11 mission, the capsule carrying a two-man Russian-American crew bound for the International Space Station (ISS) landed safely in Kazakhstan.
Russian cosmonaut Aleksei Ovchinin and U.S. astronaut Nick Hague were unhurt.
Skorobogatov added that two more Soyuz rockets may have the same defect and that additional checks were being introduced into the rocket-assembly process.
The chief of the Energia Rocket and Space corporation, Sergei Romanov, said at the commission's presentation that the launch failure caused the change of schedules for the next launches to the ISS.
"The cargo rocket's launch has been postponed from October 31 to November 16 and the launch of the manned Soyuz MS-11 has been moved up to December 3," Romanov said.
The current crew working aboard the ISS since June 6 consists of Sergei Prokopyev of Russia, Serena Maria Aunon-Chancellor of the United States, and Alexander Gerst of Germany.
The next crew -- Oleg Kononenko of Russia, Anne Charlotte McClain of the United States, and David Saint-Jacques of Canada -- was initially scheduled to be sent to the ISS in late December, but that launch was rescheduled after the October 11 accident.
