An oversight board convened by International Launch Services (ILS) to investigate the Nov. 26 launch failure of a Proton/Block DM rocket from Baikonur Cosmodrome in Kazakhstan has completed its initial review. It has identified problems with engine components of the Block DM’s upper stage made by RSC Energia.

The ILS board met last week in Moscow with members of the Russian State Commission that investigated the Nov. 26 launch. The mission left the SES Astra 1K satellite in a lower-than-planned orbit and delayed the January launch of an SES Americom spacecraft on another Proton/Block DM launch vehicle.

The anomaly occurred at the start of the second Block DM main engine burn. Excessive fuel in the main engine ignited and caused extraordinarily high temperatures that destroyed the engine, the Russian commission found. The commission attributed the failure to contamination in engine components of the Block DM upper stage. The engine propellant was not cited as a potential root cause.