Proton/Breeze-M Cleared To Resume Flying

Breeze-M Upper Stage (Credits: Khrunichev).

A Russian state board of inquiry announced on August 30 that the cause of the August 18 failure of a Proton rocket upper stage has been found. According to the Russian space agency Roscosmos, the Breeze-M failure was due to a badly programmed sequence for its guidance system, which resulted in an off-nominal orientation of the upper stage, injecting the Express-AM4 satellite into the wrong orbit. The announcement stressed that the performance of other Breeze-M flight control systems has been within specs. Roscosmos stated that corrective actions have been taken, clearing the vehicle to resume operations: the launch schedule will be announced shortly.

The Express-AM4 satellite, built by Astrium, is currently stuck in a useless orbit. In the days following the launch, Roscosmos failed to make contact with the satellite, which has not fully deployed.