Proton-M returns to service with EchoStar XXI.
Russia’s venerable Proton-M rocket made its return to flight launch June 8 after more than a year of being grounded. EchoStar XXI kicked off Proton’s 2017 launch campaign following the longest downtime between Proton flights in the vehicle’s 52 year history. The booster launched the 15,150 pound EchoStar XXI communications satellite into Geostationary Transfer Orbit from the Baikonue Cosmodrome in Kazakhstan at 11:45pm EDT, June 7.
Nine hours and 13 minutes after liftoff, EchoStar XXI separated from the Briz-M upper stage after completing five transfer burns. Proton was grounded following a a June 9, 2016 incident which saw the booster’s second stage prematurely shut down. Although that mission’s payload - the Intelsat 31 satellite - still successfully made it into GTO, Roscosmos grounded the booster until the cause of the shutdown was known. Investigation revealed massive quality control issues at the rocket’s manufacturing facility near Moscow. Just as Proton was ready to renter service in December, the failure of a Soyuz-U rocket’s upper stage prompted inspectors to further postpone Proton’s flight. Both vehicle’s upper stage engines are made by the same manufacture.
Proton experienced multiple failures between 2014 and 2015 that resulted in a loss of mission scenario, but Roscosmos hopes to have cleared all potential issues with the vehicle for the time being. P/c: Roscosmos.
