article image

Proton rocket launches Russian communications satellite

Anatoly Zak, Spaceflight Correspondent
Mar 19, 2015, 14:43 UTC

Sen—Russia's workhorse rocket successfully delivered a fresh communications satellite to build up the nation's broadcasting, telephone and Internet capacity.

The Proton-M rocket blasted off into the night sky over Baikonur Cosmodrome in Kazakhstan exactly as scheduled at 22:05 UTC, 6:05 EDT on Wednesday (01:05 Moscow Time on Thursday). The four-stage booster carried the Ekspress-AM7 communications satellite built by the European consortium Airbus Defense and Space for the Russian state-owned operator GPKS.

After its deployment high above the Eastern Coast of Africa, the 5,720-kilogram satellite will offer TV, radio, telephone and Internet services across much of Western Russia, Europe, Central Asia, India and Africa during its expected 15-year life.

To build Ekspress-AM7, Airbus relied on its tried and tested spacecraft dubbed Eurostar-E3000. The same modular platform also served as a basis for a pair of ill-fated Ekspress satellites, which were lost in botched Proton launches in 2011 and 2014. The preparations for the current Ekspress launch was marred in controversy last year, after the European Union had banned imports of sensitive technologies into Russia in the wake of Moscow's annexation of Crimea and the conflict in Ukraine. However, despite concerns, Ekspress-AM7 had made it to Kazakhstan in February for its integration with its launcher.

This time, the Proton-M rocket performed by the book, placing the satellite and the Briz-M (breeze) space tug onto a suborbital trajectory over Southern Russia. Briz then fired its engine to reach an initial parking orbit and during the following nine hours conducted four more maneuvers to boost Ekspress-AM7 to an egg-shaped orbit passing as close as 5,410 kilometers from Earth but extending 35,786 kilometers at its highest point.

Following the separation from Briz-M, the satellite will eventually enter a circular geostationary orbit 36,000 kilometers over the Equator under its own thrust. In turn, the Briz-M space tug was scheduled to make two small maneuvers to get out of the heavily trafficked route, after which valves on its pressurized tanks will be opened to vent their explosive contents. The procedure is designed to avoid a repetition of past incidents, when harsh sunlight in space would heat the rocket stage to a point of explosion, resulting in clouds of dangerous debris prolefirating across the near-Earth space.

The delivery of Ekspress-AM7 was the second mission of the Proton rocket in 2015 out of as many as 11 launches of Russia's heaviest space booster expected before the end of the year. Counting the latest flight, Proton made 403 launches since its introduction nearly half a century ago.