PARIS — A Russian Soyuz rocket on Dec. 28 successfully launched six Globalstar mobile-communications satellites in the third of a planned four Soyuz liftoffs scheduled to place Globalstar’s 24 second-generation spacecraft into low Earth orbit, Globalstar and launch services provider Arianespace announced.
Covington, La.-based Globalstar said the satellites were healthy in orbit.
Operating from Russia’s Baikonur Cosmodrome in Kazakhstan and equipped with the restartable Fregat upper stage — and using a different third-stage configuration than the Soyuz variant that failed at launch on Dec. 23, destroying a Russian military communications satellite — the Soyuz 2.1a vehicle placed the six 650-kilogram Globalstar spacecraft into a 920-kilometer low Earth orbit.
After delivering the satellites in two sequences, the first separating two spacecraft and the second freeing the other four, the Fregat upper stage reoriented itself to be destroyed on re-entry into the Earth’s atmosphere.
In the coming months the satellites will use their on-board power to climb into a 1,400-kilometer operating orbit, where they will join the rest of the Globalstar constellation.
A fourth launch of six second-generation Globalstar satellites is scheduled for the first half of 2012. Once in orbit, these satellites will complete Globalstar’s second-generation constellation, at least for now.
Globalstar and its satellite prime contractor, Thales Alenia Space of France and Italy, are in arbitration proceedings to determine whether the manufacturer is obliged to build another six Globalstar satellites under the contract terms Globalstar is demanding. A Jan. 24 hearing is scheduled on the matter.
Globalstar’s business of providing mobile voice and data communications worldwide has been suffering since 2007, when the performance of its current constellation of 48 satellites began degrading under the suspected effects of radiation. Globalstar has since lost most of its ability to provide two-way voice links, although the less-profitable data communications capability has been maintained.
Restoring the voice capability is Globalstar’s principal objective with the second-generation satellites, which in addition to being protected against similar radiation damage also feature a design offering 15 years of service life, compared with seven to eight years for the first generation.
The Dec. 28 launch had been delayed by several weeks to permit Thales Alenia Space to replace momentum wheels on one of the six spacecraft. Momentum-wheel defects have affected several second-generation Globalstar spacecraft launched in October 2010 and last July. Thales Alenia Space and Globalstar have agreed to a software patch that will permit the spacecraft to function, in most operating modes, with just two momentum wheels. Normally three of the four on-board momentum wheels are required.
The launch was conducted by the Arianespace launch consortium of Evry, France, and its Starsem affiliate, which has responsibility for Soyuz commercial launches from the Baikonur spaceport. The Russian space agency, Roscosmos, and Soyuz prime contractor Samara Space Center of Samara, Russia, are Starsem shareholders, alongside Arianespace and Europe’s Astrium space hardware manufacturer.
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