Proton poised for launch of dual satellites

Two Russian television broadcast and data transmission satellites are ready for launch Saturday on top of a Proton rocket from the Baikonur Cosmodrome in Kazakhstan.

The dual-satellite launch is set for 2308 GMT (7:08 p.m. EDT) Saturday, or 5:08 a.m. local time at the Baikonur Cosmodrome.

The liquid-fueled launcher's payloads are the Express AT1 and Express AT2 communications satellites. Built by ISS Reshetnev, the satellites will broadcast television signals and data services for the Russian Satellite Communications Co., Russia's state-owned civil telecom satellite operator.

The Proton's three-stage core vehicle will fire for about 10 minutes before giving way to a Breeze M upper stage to inject the payloads into their high-altitude orbits.

Express AT1 and Express AT2 are stacked together inside the Proton's nose fairing on top of the rocket's Breeze M upper stage, which will fire four times before deploying the satellites into orbit about nine hours after liftoff.

Express AT1 will be positioned in geostationary orbit 22,300 miles above the equator at 56 degrees east longitude, beaming signals over Eastern Europe and Russia through 32 Ku-band transponders.

Express AT2 is heading for an operating post at 140 degrees east longitude to cover Asia and Russia's Far East with 16 Ku-band transponders.

Saturday's launch will mark the second flight of a Proton rocket in 2014, and the first of several Proton launches scheduled over the next few months for Russian government customers.

Commercial Proton flights are managed by International Launch Services, a U.S.-based launch services provider owned by Khrunichev State Research and Production Space Center, the Proton's Russian contractor.

Russian federal missions, such as the launch of Express AT1 and Express AT2, are purchased directly through Khrunichev instead of ILS.

Credit: Roscosmos