Proton Strands SES Astra 1K in Low Orbit

The second firing of the DM3 upper stage of a Russian Proton K failed after 1 second, stranding Astra 1K in a useless orbit. The spacecraft was placed in a 175.5 km (94.8 nmi) circular orbit, an orbit which could decay by weeks end. The satellite was supposed to be placed into a geosychronous transfer orbit (GTO) of 3300 km by 35,786 km, inclined at 26.3 degrees. The Proton launched from Baikonur Cosmodrome, pad LC81/23, at 23:04 UTC on November 25.

The Blok DM3 upper stage, built by RSC Energia, performed its first burn as planned, placing the spacecraft in a circular parking orbit of 175.5 km (94.8 nmi), inclined at 51.6 degrees. Preliminary flight information indicates that one second after starting the second burn of the second stage engines, the automatic unit of the Blok DM3 initiated a command for separation from the satellite. Two additional firings of the Blok DM3 were scheduled to push the satellite into a geosynchronous transfer orbit after which spacecraft separation was planned almost seven hours after liftoff. Most Proton launches do not require an extra firing by the upper stage, but the extra-heavy mass of Astra 1K made an extra burn necessary. There was no immediate information on whether or not the satellite was able to deploy its solar arrays. (The Russian word blok translates into English as stage.)

A Russian State Commission is being formed to determine the reasons for the anomaly. ILS will provide details as soon as definitive information is available for release. A copy of the official statement from Khrunichev will also be made available upon translation. In parallel with the State Commission, ILS will form its own Failure Review Oversight Board to review reasons for the anomaly and define a corrective action plan. ILS has suspended further Proton K launches until the cause of the accident can be determined.

The next scheduled ILS Proton flight will be the Proton M using the Briz M upper stage. It is to launch Telesat Canada's Nimiq 2. The Briz M has flown successfully eight times in various configurations.

The project cost SES Astra US$277.5 million (280 million euros). SES ASTRA has full insurance coverage for the ASTRA 1K program. The satellite was planned to replace three Astra satellites now in orbit and serve as an orbital spare for four others. (1 USD = 1.00884 EUR)

The Astra 1K was built by Alcatel Space for SES Global. The 5250 kg (11,571 lbm) spacecraft used a Spacebus 4000, being the heaviest commercial telecommunication satellite built to date. It was to have been positioned at 19.2°E, carrying 52 Ku-band and 2 Ka-band transponders. The launch failure will not affect existing services at 19.2° East. Furthermore, ASTRA 2C, already operational at 19.2° East, offers comprehensive back-up for the ASTRA low-bands at this slot and will remain there until further notice. Interactive Ka-Band services will continue to be provided by the existing Ka-band payload on ASTRA 1H.

The Proton K rocket, since 1996, has flown 24 previous missions for ILS all using the Block DM upper stage. A mission failure in December 1997 also involved the Block DM. The Proton family, including the upgraded Proton M with the Khrunichev-built Briz M upper stage, has flown 26 consecutive successful missions since February 2000.

International Launch Services (ILS) is a joint venture of Lockheed Martin Corp., with Russian companies Khrunichev State Research and Production Space Center and RSC Energia. ILS provides launch services on the Proton and the Atlas vehicles.  

SES Astra operates a constellation of 13 spacecraft providing direct broadcast television, radio and Internet access service to customers throughout Europe. SES Global operates 29 satellites worldwide.

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