According to Russian chief investigator Igor Skorobogatov, cited by Euronews, the cause of the incident was a “deformation of the stem of the contact separation sensor," which in turn led to the first stage of the rocket hitting the second one. This caused the mission to be aborted and all Soyuz missions grounded.
The Russian official claims that there might be two more Soyuz rocket affected by this fault and additional checks will be introduced in the future to prevent further incidents.
As the problem with the October launch seems to have been found, NASA and Roscosmos are planning a new Soyuz launch on December 3. On board the flight will not be the two men of the aborted mission, Nick Hague and Aleksey Ovchinin, but three other astronauts.
The new capsule will be commanded by cosmonaut Oleg Kononenko, with the two flight engineers being Canadian David Saint-Jacques and Anne McClain, both at their first flight into space.
If everything goes as planned, the three will be joining the crew on the ISS, who will depart the station some time after that.
The crew of mission MS-11, or Expedition 58, will spend six months in space conducting 250 research investigations and technology demonstrations. They will also be in charge with handling the arrival of the Crew Dragon and Starliner spacecraft in their first unmanned flight tests next year.
CA: @0:5BK-=>A8B5;O «!>N7-$» A ?8;>B8@C5— !!! (@roscosmos) 1 noiembrie 2018