Breeze-M investigation concludes

by Chris Bergin

A Russian State commission has concluded that an anomaly in the Breeze-M upper stage main engine was at fault for the failed launch of the Arabsat 4A satellite in February. The most probable cause of the oxidizer supply interruption was a foreign particle that blocked a nozzle of the booster hydraulic pump.

The amount of time it will take to undergo corrective action will ultimately postpone the May 17th launch from the Baikonur Cosmodrome of the Hot Bird 8 satellite.

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‘The commission concluded that an anomaly in the oxidizer supply system caused the Breeze M upper stage main engine to shut down prematurely,’ noted an International Launch Services (ILS) press release.

‘Based on telemetry data, the most probable cause of the oxidizer supply interruption was a foreign particle that blocked a nozzle of the booster hydraulic pump, the commission stated.’

Flight operations should be able to resume after corrective actions have been implemented, the commission stated, with implementation of such steps is expected by the end of May.

The commission noted the Proton M first stage concluded its role successfully, but at 5,536 seconds after lift-off, during the second burn of the Breeze M, an unplanned main engine shutdown occurred.

‘In accordance with standard procedures, the flight control system produced an emergency command, and at 5,541 seconds after lift-off the spacecraft was separated from the upper stage, into an orbit of 51.5 degrees inclination, 14,679 km apogee altitude and 506 km perigee altitude,’ added the commission.

‘The State Commission reviewed all possible failure scenarios based on telemetry data received from the Breeze M upper stage. To verify possible scenarios, various units have been tested in test stands, including test firing of the main engine.

‘The commission is developing corrective actions for additional inspection of the Breeze M and Breeze KM main engines, which are of the same type, to prevent recurrence of similar anomalies.’


Concurrently, the ILS Failure Review Oversight Board will commence a series of meetings in Moscow. The FROB will review the final report and corrective action plan in accord with U.S. and Russian government technology control regulations, with a goal of completing its work by the end of May.

This won’t conclude in time to save the current slot open to the Hot Bird 8 launch – which was the next mission to use the Breeze-M upper stage during it’s ascent.

Hot Bird 8 – the largest satellite built by Eutelsat for its customer EADS ASTRIUM – could be pushed down the schedule to the end of this year, or move to a launch via Arianespace’s Ariane 5 launcher, which recently launched one of the earlier range, the Hot Bird 7A.

Hot Bird 8 is important to its customer, given its mission to replace existing HOT BIRD capacity, joining HOT BIRD 7A, 13 degrees East.

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