The fault in the Proton rocket which failed back on May 16th while launching Russia’s Express AM4R satellite has been identified. International Launch Services (ILS), which handles the commercial launches for the Proton system, appointed its own high-level Failure Review Board to examine the evidence.
The Review Board says that its initial assessment blames the “loss of structural integrity of a bolted interface” where it provided a connection between the Stage III engine turbo-pump to the main engine structural frame.
“The loss of integrity led to an excessive steering engine turbo pump vibration environment that damaged a fuel inlet line to the oxidizer gas generator, resulting in a fuel leak. The loss of fuel led to the premature shutdown of the turbopump and loss of stage control authority and ultimately loss of mission approximately 545 seconds into the flight. Additionally, the FROB concurs that the identified corrective action plan will adequately address the identified probable cause and contributors to the failure,” says the Review Board statement.
ILS says it is rescheduling its Proton launch manifest following on from the successful launch last weekend of the Proton rocket.