A Proton rocket delivered two communications satellites to orbit Monday after a nine-hour ascent from the Baikonur Cosmodrome, achieving a successful launch with payloads for Russia and Kazakhstan.

The Proton rocket lifts off at 0425 GMT (12:25 a.m. EDT; 10:25 a.m. local time) from the Baikonur Cosmodrome in Kazakhstan. Credit: Roscosmos
 
The Luch 5V and Kazsat 3 spacecraft, both manufactured by Russian satellite-builder ISS Reshetnev, launched at 0425 GMT (12:25 a.m. EDT) from the Baikonur Cosmodrome in Kazakhstan.

The satellites were mounted on top of a Proton rocket, which roared away from the historic space base at 10:25 a.m. local time. The three-stage Proton booster and Breeze M upper stage put the dual-payload package in a preliminary orbit about 15 minutes later.

The launch marked the 396th flight of a Proton rocket since 1965 and the Proton's third mission of the year. The Proton and Breeze M are built by Moscow-based Khrunichev State Research and Production Space Center.

The hydrazine-fueled Breeze M upper stage fired several times before releasing Luch 5V at 1317 GMT (9:17 a.m. EDT), followed by deployment of Kazsat 3 about 40 minutes later, according to the Itar-Tass news agency.

Both satellites will be stationed in geosynchronous orbit at an altitude of 22,300 miles.

Monday's launch was managed by Khrunichev as part of Russia's federal space program. U.S.-based International Launch Services, a wholly-owned subsidiary of Khrunichev, arranges commercial Proton missions for international customers.

Luch 5V will relay telemetry, commands and other communications between ground controllers and Russian spacecraft in low-altitude orbits. The Luch satellite fleet, operated by the Russian Federal Space Agency, also tracks rockets and their upper stages in flight and is Russia's counterpart to NASA's Tracking and Data Relay Satellite System.

The Luch 5V (left) and Kazsat 3 (right) satellites together in their factory. Credit: ISS Reshetnev
 
The data relay satellites help ensure stable communications links with satellites, reducing reliance on a spotty network of ground stations scattered around the globe.

Fitted with Ku-band and S-band payloads with two large deployable mesh antennas, the Luch 5V spacecraft launched Monday is the third member of the newest generation of Luch satellites, joining the Luch 5A and Luch 5B satellites launched in December 2011 and November 2012.

Kazsat 3 is the third communications satellite in Kazakhstan's national communications network providing television and high-speed Internet services. Kazsat 1 and Kazsat 2 launched in 2006 and 2011.

ISS Reshetnev designed and built Kazsat 3 for the Republican Center for Space Communications, an agency of the Kazakh government. Kazsat 3's communications payload, comprised of 28 Ku-band transponders, was supplied by Thales Alenia Space.

Kazsat 3 is designed for a 15-year service life.

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