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Russia launches fresh GPS satellite

Anatoly Zak, Spaceflight Correspondent
Dec 1, 2014, 16:05 UTC

Sen—The Russian military has launched a long-delayed experimental satellite designed to upgrade the nation's global-positioning constellation, GLONASS.

A Soyuz-2-1b rocket with a Fregat upper stage blasted off from a snow-blanketed Pad No. 4 at Site 43 at the Russian northern space center in Plesetsk as scheduled at 21:52 UTC (4:52 p.m. EST) Sunday, 30 November. (It was already past midnight local time Monday in Plesetsk). Onboard was a second copy of the GLONASS-K satellite which was long expected to replace the current GLONASS-M spacecraft comprising Russia's 24-bird satellite navigation constellation.

The upgraded GLONASS-K spacecraft is lighter than previous-generation satellites and, more importantly, it has an operational warranty of 10 years, instead of a seven-year life guaranteed by its developer, ISS Reshetnev, for GLONASS-M satellites. The longer lifespan was achieved thanks to an unpressurized structure housing sensitive electronics capable of operating in the vacuum of space.

GLONASS-K also sports more efficient solar panels for power supply and expanded band of navigational signals. In the course of its development, GLONASS-K was given additional responsibility to carry KOSPAS-SARSAT transmitters designed to relay SOS signals from ships and aircraft to rescue services, after the Russian space agency, Roscosmos, had scrapped its plans to deploy dedicated satellites for the job.

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An artist's rendering of a GLONASS-K satellite in orbit. Image credit: Roscosmos

However all the upgrades to the Russian GLONASS satellites came at a high price. The first GLONASS-K satellite flew in 2011, years later than promised. After its deployment in orbit more technical glitches were discovered in the first and in the follow-on satellite, pushing the launch of GLONASS-K No. 2 around three years behind the original schedule. Its exact launch date remained uncertain as late as the fall of this year.

When, the GLONASS-K No. 2 finally lifted off Sunday, three stages of the Soyuz-2-1b rocket first inserted the payload section, including the Fregat upper stage and the satellite, on a ballistic suborbital trajectory aligned with an inclination 64.8° toward the Equator. The Fregat then took over the powered flight, firing its engine for around 19 seconds to reach a 212 by 241-kilometer parking orbit.

After a period of a passive flight, the Fregat restarted its engine for 564 seconds to enter an elliptical 278 by 19,145-kilometer orbit. Upon reaching an apogee (the highest point) of this orbit, Fregat performed a third 224-second maneuver entering its final nearly circular orbit with an altitude of about 19,140 kilometers.

The launch successfully concluded with the separation of the GLONASS-K No. 2 satellite from Fregat at 01:25 UTC on December 1, a Russian military spokesman quoted by official Russian media said.