Zak: Another Problem with Russia's Briz Upper Stage?

Anatoly Zak of RussianSpaceWeb.com reports that the Briz-KM upper stage used for a Russian launch earlier this week did not complete its final burn.

The Briz (Breeze) upper stage has been the source of problems for the Russian space program in several incidents in the past two years, most recently the December failure of a Proton/Briz-M configuration to place the Yamal 402 spacecraft into the correct orbit.  The spacecraft’s own stationkeeping engines had to be used to place it into its proper orbit, reducing its operational lifetime from 15 to 11 years.

International Launch Services (ILS), which markets Proton rocket launches, is waiting for the report of the investigation into the December anomaly before resuming commercial Proton launches. 

This week’s launch was of a different launch vehicle, named Rokot (or Rockot), which uses a variant of that upper stage designated Briz-KM.   Zak reports that although the three small military communications satellites it carried were delivered to the correct orbit, the Briz-KM upper stage did not fire a final time to lower its perigee.  That maneuver is used to hasten its reentry.  Briz-M upper stages have exploded in the past, creating debris that pose hazards to other satellites. 

Jonathan McDowell, an experienced satellite tracker who authors Jonathan’s Space Report, concurred that the final Briz-KM firing does not appear to have occurred.

No word yet from Russian sources.