spacetoday.net: Proton upper stage failure strands two satellites in transfer orbit

Posted: Tue, Aug 7, 2012, 4:54 PM ET (2054 GMT)
Proton-M launch of SES-5 (ILS)

The upper stage of a Proton rocket that lifted off Tuesday malfunctioned, stranding its payload of two communications satellites in an intermediate orbit. The Proton M rocket lifted off from the Baikonur Cosmodrome at 3:31 pm EDT Monday (1931 GMT Monday, 1:31 am local time Tuesday) carrying the Express MD2 and Telkom 3 satellites. The two were destined to go to geosynchronous transfer orbit, but a malfunction with the Breeze M upper stage stranded the spacecraft in an "off-nominal intermediate" orbit with an apogee of only 6,000 kilometers, far short of GEO and with little chance of rescue. The failure was apparently associated with the third of four engine burns by the upper stage. Russian media reports indicate that Proton launches will be suspended while the failure is being investigated.