Russian Proton rocket blasts off on first launch since May failure

(Photo Credit: Roscosmos)

Russia’s heavy-lift Proton rocket has successfully returned to flight and placed a Russian military satellite into geostationary orbit just four months after an explosive failure.

The Proton Breeze M launch vehicle successfully lifted off from the Baikonur Cosmodrome in Kazakhstan at 12:23 a.m. Moscow time. This was the 5th launch of the Proton vehicle this year.

The satellite’s mission and characteristics were not disclosed however Roscosmos, the Russian Federal Space Agency, confirmed that the rocket launched successfully and that the payload cleanly separated from Proton’s upper stage and was placed into the desired orbit.

The successful flight should put Proton, which has a long list of customers waiting to launch, back into the rotation for commercial telecommunications satellite fleet operators. Proton’s launch services had been temporarily halted following a failure during a routine mission in May that destroyed the vehicle and its payload, the Russian Satellite Communications Company’s (RSCC) Express AM4R satellite.

The Proton-M rocket successfully lifted off, however during its acceleration into low Earth orbit, it was found that the satellite and the Briz-M booster failed to separate from the rocket, resulting in their destruction.

(A Proton rocket – Photo Credit: Roscosmos)

Following an investigation into the incident, Reston, a Virginia-based international launch service that manages commercial Proton missions, announced that the cause of the May failure was due to “the loss of structural integrity of a bolted interface that attaches the Stage III steering engine turbopump to the main engine structural frame.”

“The telemetry, analysis and test indicate that at least one bolt holding the steering engine turbopump to the main engine frame lost preload [became loose] at approximately 45 seconds into the 3rd stage burn.”

“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.”

With the investigation concluding that the failure was a freak accident, Proton have been given the go ahead to resume normal operations, and now the vehicle will partake in up to four more launches by the end of the year, for both commercial and government customers.

The Proton vehicle is manufactured by Khrunichev State Research and Space Production Centre of Moscow. This was the 398th Proton launch since its inaugural flight in 1965.