PARIS โ€” Six Globalstar mobile communications satellites were successfully placed into low Earth orbit Feb. 6 by a Russian Soyuz-Fregat rocket, bringing Globalstarโ€™s second-generation constellation to 24 spacecraft and permitting the company to approach full operational status after six years of degraded service, Globalstar and launch services provider Arianespace said.

Covington, La.-based Globalstar said all six satellites were healthy in orbit.

Operating from Russiaโ€™s Baikonur Cosmodrome in Kazakhstan, the Soyuz vehicle, fitted with a Fregat restartable upper stage, inserted the six 650-kilogram satellites into their intended 920-kilometer orbit.

Once all 24 second-generation satellites are operating with six first-generation spacecraft that were launched later than the others, Globalstar will be able to restore its two-way voice service.

Performance of the first-generation constellation began to degrade in 2007 and ultimately forced Globalstar to all but abandon voice service, which it calls Duplex, in favor of less-profitable data services. The degradation is believed to have been caused by radiation in the satellitesโ€™ operating orbit.

In recent months, as the second-generation satellites were placed into their operating positions, Globalstar said more and more customers were reporting success in making voice calls. The company said the six final second-generation satellites will be in service by this summer, and that the first two will be operational by March.

โ€œWe fully expect Duplex service to be restored to the high level of quality that Globalstar customers historically enjoyed,โ€ Globalstar Chief Executive Jay Monroe said in a statement. Monroe and his familyโ€™s Thermo group of companies financed a large portion of Globalstarโ€™s second-generation effort, with help from the French export-credit agency, Coface.

Globalstarโ€™s second-generation satellites were manufactured by Thales Alenia Space of France and Italy. Globalstar and Thales Alenia Space are still negotiating terms for a final batch of six satellites. The spacecraft, with reinforced radiation protection, are designed to operate for 15 years, about double the contractual life of the first generation.

The Evry, France-based Arianespace consortium, with its Russian-French Starsem affiliate, was the launch service provider.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.