Russian Rocket Launches New Communications Satellite
The communications satellite Inmarsat 4 F3 launches into space atop a Russian-built Proton rocket on Aug. 19, 2008.
Credit: ILS.

PONTE VEDRA, Fla. - The third and last Inmarsat 4 mobile-broadband satellite was successfully placed into orbit Tuesday by an International Launch Services (ILS) Proton Breeze M rocket, ILS and Inmarsat announced.

The launch completed a decade-long, $1.5 billion investment by London-based Inmarsat and returned ILS to commercial service five months after a failure that forced a redesign of the Proton Breeze M upper stage.

The 13,139-pound (5,960-kg) Inmarsat 4 F3 satellite will be operated from 98 degrees west. Once its operations begin there, the two other Inmarsat 4 satellites will be moved to new orbital slots to optimize global broadband data services from the three-satellite system. Moving these two satellites will cause partial shutdowns of Inmarsat broadband services for a five-week period as the Inmarsat 4 F2 is moved from 53 degrees west to 25 degrees west, and then for a three-week period during the relocation of Inmarsat 4 F1 from 64 degrees east to 143.5 degrees east.

Operating three satellites in geostationary orbit will permit Inmarsat to offer broadband data and hand-held telephone access globally, except for the polar regions. The two previously launched Inmarsat 4 satellites, in orbit since March and November 2005, have provided services to 85 percent of the Earth's land mass but have left broad coverage gaps in the Pacific Ocean region.

Inmarsat, whose stock is traded on the London Stock Exchange, had been under close investor scrutiny following its decision to be the first customer for the ILS Proton Breeze M rocket after the March failure, which left a commercial satellite in a useless orbit. Inmarsat Chief Executive Andrew Sukawaty told investors Aug. 6 that the Inmarsat 4 F3 launch was fully insured and that the two operational Inmarsat 4 spacecraft covered the world's land areas sufficiently well to assure continued service even if aeronautical and maritime coverage growth depended on the third satellite being in orbit.

Sukawaty also said Inmarsat, which has ordered a large new satellite design, called Alphasat, from Astrium Satellites for launch in 2012, could use Alphasat to replace the third Inmarsat 4 in the event of a launch failure.

Reston, Va.-based ILS is majority-owned by Khrunichev State Research and Production Space Center of Moscow, which is the prime contractor for the Proton Breeze M rocket. The company has an active launch schedule for the coming months, as do its two principal competitors in the commercial launch industry, the Arianespace consortium of Evry, France, and Sea Launch Co. of Long Beach, Calif.