Globalstar's satellite fleet has four new members after aRussian Soyuz rocket launched the replacement communication platforms Saturdayto bolster the company's aging constellation.
The Soyuz launched at 2012 GMT (4:12 p.m. EDT) from Complex31 at the Baikonur Cosmodrome in Kazakhstan. The three-stage booster and anattached Fregat upper stage rocketed into space and released the foursatellites about 100 minutes after liftoff.
The rocket was shooting for a circular orbit about 572 mileshigh with an inclination of 52 degrees. The Fregat upper stage fired two timesto reach the targeted orbit, according to Starsem, the international marketingfirm for the Soyuz rocket.
The satellites will use their own maneuvering thrusters toraise their orbits to an altitude of 876 miles over the next few weeks beforeeventually placing themselves into open slots in Globalstar's operationalfleet.
Globalstar satellites provide voice and data communicationsto more than 275,000 activated fixed and mobile units in more than 120countries.
The satellite fleet consists of 40 active spacecraft plusadditional orbital reserves, and the company's communications relay service canreach more than 80 percent of the Earth's surface. The craft are spreadthroughout six orbital planes to ensure customers always have a satelliteoverhead.
The four satellites launched Saturday, in addition to anotherquartet launched earlier this year, were the last in the company's originalbatch of spacecraft that were deployed beginning in 1998.
The 992-pound craft were built by prime contractor SpaceSystems/Loral and kept on Earth as ground spares until Globalstar needed toreplenish its constellation. The satellites are designed to last for at leastseven-and-a-half years.
The company invested about $120 million in the two launches,according to a Globalstar written statement.
"Although they represent the completion of our currentgeneration space segment, these satellites along with the four launched earlierthis year, will also facilitate a seamless transition into oursecond-generation constellation beginning in 2009," said Tony Navarra,president of global operations for Globalstar.
C-band antennas mounted on each satellite's Earth-facingdeck communicate with Globalstar gateways, ground stations that distributesatellite phone calls to conventional terrestrial telephone networks.
The gateways help reduce the company's operating costsbecause they use existing telephone networks and house many critical systems,reducing the satellites' complexity, officials said.
Globalstar satellites also feature an array of L-band andS-band antennas to link with user telephones and modems.
Globalstar announced in February that engineers discovered a seriousproblem with S-band antennas on satellites already in orbit. The companysaid the issue could hinder two-way communications services beginning nextyear, according to a filing with the Securities and Exchange Commission.
Engineers observed degradation in the performance of theantennas' solid-state power amplifiers, which was decreasing the quality oftwo-way communications, the SEC filing said.
Officials believe the eight replacement satellites launchedthis year will extend the current fleet's lifetime through 2009, when the firstof eight launches is scheduled to deliver upgraded satellites to space.
Globalstar awarded the satellite development contract toThales Alenia Space in December, followed last month by the selectionof Arianespace as the launch services provider. Launches are slated tobegin in mid-2009 aboard Soyuz rockets launched from a new launch pad at theEuropean spaceport in French Guiana.
The second-generation constellation will provide faster dataspeeds to facilitate video communications and additional call capacity through2025, Globalstar said.
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