Six Globalstar Satellites in Healthy Orbit
On December 28th the Russian Soyuz rocket successfully launched six Globalstar satellites. This is the third of four planned Soyuz launches to place 24 Globalstar second generation satellites into low earth orbit.
Globalstar has stated the six satellites are now in a healthy orbit.
The satellites were launched from Russia’s Baikonur Cosmdrome in Kazakhstan. The Soyuz rocket was equipped with the restartable Fregat upper stage and it was using a different third stage than the Soyuz variant that failed on December 23rd, destroying a Russian military communications satellite. The Soyuz 2.1 rocket placed six 650 kilogram Globalstar satellites in a 920 kilometer low earth orbit.
The satellites where delivered in two sequences, the first separating two spacecrafts, and the second deploying the other four. The Fregat upper stage then positioned itself to be destroyed on re-entry.
In the next number of months the satellites will use their own power to climb to a 1,400 kilometer orbit. This is where they will join the rest of the Globalstar constellation.
The next launch of six new second generation Globalstar satellites is planned to be launched in the second quarter of 2012. When the fourth set of satellites are in orbit this will complete the Globalstar second generation constellation with further launches planned to enhance the Globalstar constellation.
The first generation Globalstar constellation has been suffering duplex transmission problems since 2007. This has affected Globalstar’s voice and two way data service. The simplex data service has not been affected during this period.
Globalstar’s second generation satellites will restore Globalstar’s voice and duplex data service. The new constellation of satellites will be protected against the radiation damage that damaged the first constellation of satellites. It is estimated that the second generation of satellites will offer 15 years of service life.
The third launch on December 28th was delayed by a number of weeks to allow Thales Alenia Space to replace momentum wheels on one of the six satellites. Problems with the momentum wheels have affected a number of the second generation Globalstar satellites that were launched in October of 2010. Globalstar and Alenia have developed a software patch that will allow the affected satellites to function with two momentum wheels.