Proton launches resume

On September 28, 2014, a Proton-M launch vehicle with a Briz-M orbit-insertion upper stage lifted off from Baikonur Cosmodrome, successfully inserting a Luch relay satellite into a near-nominal orbit. This marked the resumption of Proton operations following a failed launch on May 16, 2014, when an upper-stage malfunction prevented the orbiting of the Express-AM4R communications satellite. 

The cause of the accident was made public on June 11: a disintegrated bearing in the upper-stage thruster turbopump. Roscosmos head Oleg Ostapenko commented: “Our final conclusion backs the preliminary theory voiced in the initial phase of the inquiry. The telemetry and analytical information we have indicate that a bearing must have been disintegrated in the turbopump.”

The accident, and the subsequent grounding of the Proton fleet, affected the current launch schedule. The constrained throughput capacity of the Briz-M fuelling area also played a role. Early in 2014, the plan was to launch 14 Protons during the year. Only five launches had been performed by late September; another four rockets are expected to be launched by year-end.