The launch of a Russian Proton-M carrier rocket with British communications satellite Inmarsat-5F2 has been scheduled for January 30 from the Baikonur space center that Russia leases from Kazakhstan, Russian Federal Space Agency Roscosmos told TASS Monday.

“The Inmarsat-5F2 spacecraft was delivered to Baikonur on December 18. Specialists of the Boeing manufacturer company’s space programs unit immediately started preparing and checking it in the integration and test building,” Roscosmos said.

The Proton carrier rocket and the Briz-M upper stage have been developed and are manufactured by the Khrunichev State Research and Production Space Center. The modernized Proton-M, fitted out with the Briz-M upper stage, is capable of putting into geostationary transfer orbit payloads weighing more than 6 metric tons.

The Inmarsat-5F2 is the second of three Inmarsat satellites of the fifth generation. It is designed to provide communications services in North and South Americas, as well as in the Atlantic region. The first of these satellites was successfully launched with the help of a Proton-M carrier rocket in December 2013.

Quelle: TASS

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Launch of Proton rocket with British Inmarsat-5 F2 satellite atop scheduled for January 30

British Satellite to Be Launched by Russian Proton-M Carrier Rocket

Proton to fly Russia's first space mission of 2015

Russia's workhorse rocket opened the nation's space activities this year with a rare daylight blastoff from the frozen steppes of Kazakhstan Sunday. A Proton-M rocket lifted off as scheduled at 12:31:00 UTC (15:31 Moscow Time, 7:31 a.m. EST) from Site 200 in Baikonur Cosmodrome. Under its payload fairing, the vehicle carried a six-ton Inmarsat-5 F2 satellite for its namesake company based in London. The giant spacecraft built by Boeing in California will be used to provide high-speed broadband voice and data communications across the American continent and the Atlantic region. The first Inmarsat-5 satellite in the planned three-bird constellation was successfully launched by a Proton rocket in December 2013. The fourth satellite could be added to the network after 2016. Like most communications satellites, the Inmarsat-5 family is designed to operate in the geostationary orbit 36,000 km over the equator, where spacecraft appear "hanging" in the sky to a ground observer, because its 24-hour orbital period exactly matches the Earth's rotation about its axis. However, Inmarsat-5 took a very long, though pre-planned, detour on his way to this popular destination in space. During its 15-hour, 31-minute climb, Proton's Briz-M space tug pushed the spacecraft as far as 65,000 km away from Earth, or nearly twice above its prescribed altitude. Counter-intuitively, the exotic launch scenario actually saved the spacecraft some gas for its own thrusters, which will be needed to place it into the operational orbit and keep it there during the satellite's projected 15-year lifespan. The mass savings became possible because farther away from Earth the satellite faced less resistance from our planet's gravitational field during an energy-hungry maneuver aimed to tilt its orbit to match the Equator. As an added benefit for the spectators on the ground, the extended flight itinerary shifted the liftoff time for the Inmarsat-5 F2 into the daylight hours in Baikonur. (Most routine Proton missions to the geostationary orbit have to take off in the depth of night, in order to catch the sunlight during prolonged phases of the ascent.) Moreover, the winter weather started clearing shortly before launch allowing the setting Sun to provide a dramatic backdrop as the Proton was thundering into the sky. The launch of Inmarsat-5 F2 is only a beginning in a very busy flight manifest for the Russian space program, which includes at least 10 more missions for the nation's heaviest operational rocket in 2015, including the launch of the third spacecraft in the Inmarsat-5 series scheduled for the middle of the year. In a step-by-step effort to improve the reliability of the Proton, the rocket for the Inmarsat-5 F2 mission was equipped with new angular velocity sensors, which tell the vehicle's computer brain its exact orientation in flight. New sensors replaced infamous PV-301 units, whose wrong installation in the upside down position led to a spectacular crash of a Proton in July 2013, just seconds after liftoff. 

Quelle: SEN

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