ILS Proton Delivers 1st Inmarsat Global Xpress Satellite to Orbit
PARIS — An( ) Proton Breeze M rocket on Dec. 9 successfully placed the first Ka-band Global Xpress satellite into a transfer orbit after launch from Russia’s Baikonur Cosmodrome in Kazakhstan.
London-based Inmarsat said the satellite, formally called Inmarsat-5 F1, was healthy in orbit and sending signals to ground stations.
Inmarsat-5 F1 is the first of four identical Global Xpress spacecraft being built by Boeing Space and Intelligence Systems of El Segundo, Calif. In return for the manufacturing contract, Boeing agreed to purchase a portion of the satellites’ Ka-band payload for several years and sell it to U.S. government customers operating mobile platforms around the world.
Boeing has also become a reseller of Inmarsat’s core L-band mobile services using the company’s existing fleet of satellites.
Inmarsat Chief Executive Rupert Pearce, in a Nov. 6 interview, said Boeing had agreed to extend its commitment to Global Xpress capacity sales in return for the contract to launch the fourth Global Xpress satellite. The first three were ordered separately with the fourth — an option in the original contract — being ordered in October.
Inmarsat-5 F1 will operate at 63 degrees east longitude in geostationary orbit to provide Ka-band mobile broadband to land-, maritime- and aeronautical-mobile markets, Inmarsat officials said.
In addition to their prime commercial business, the Global Xpress satellites are designed to permit users of the U.S. Air Force’s Wideband Global Satcom (WGS) military Ka-band system to use Global Xpress in areas where WGS is fully booked or otherwise unavailable.
Each Global Xpress satellite carries 80 fixed Ka-band beams and six steerable beams. Its high-capacity payload operates in military Ka-band and is reserved for use by NATO governments, but this capacity can be converted to civil Ka-band as necessary to meet demand.
The launch was the seventh of the year for ILS, meeting the company’s goal for 2013 despite the July failure of a Proton used for a Russian government mission that was not under ILS management.
Pearce, whose company had raised eyebrows in the industry by ordering all three Global Xpress launches aboard the same rocket, repeatedly expressed his confidence that Proton would return to flight quickly after the failure, as it has done in the past, and that the Global Xpress program would not suffer a long delay in commercial service introduction.
Weighing 6,100 kilograms at launch, Inmarsat-5 F1 was dropped off at a supersynchronous transfer orbit with an apogee of 65,000 kilometers and a perigee of 475 kilometers, inclined at 50.5 degrees relative to the equator.
The drop-off occurred 15 hours and 31 minutes after liftoff and following five burns of the Proton rocket’s Breeze M upper stage. In the coming two weeks, the satellite will fire its own engines seven times to reshape its orbit, and reduce its inclination.
Inmarsat said that by the end of December the satellite will deploy its solar arrays and antennas, after which its orbit will be raised to near-circular geostationary position some 36,000 kilometers over the equator. Payload testing should start by early February, with full commercial service to start by midyear.
Inmarsat-5 F1 is designed to operate for at least 15 years and to deliver 13.8 kilowatts of power to its payload at the end of its service life.
Inmarsat is spending $1.6 billion on the four-satellite Global Xpress program, including the construction, launch and insurance of four spacecraft and the associated ground segment. The company has not yet signed a launch service contract for the fourth satellite, whose launch date will depend on whether the first three satellites — all to be launched aboard Proton Breeze M rockets — arrive safely in orbit.
The two remaining Global Xpress satellites on Reston, Va.-based ILS manifest are scheduled for launch in mid-2014, with global commercial service from the three-satellite network by early 2015.
Pearce reiterated that Inmarsat, in part because of the Boeing take-or-pay contract, has received commitments for between 25 percent and 30 percent of the Global Xpress revenue forecast for the satellites’ first five years in orbit.
In the interview, Pearce did not gloss over the near-term difficulties in securing U.S. government, and particularly U.S. Defense Department, commitments for services that are not programs of record.
But he said while 2014 may continue to manifest the turmoil around across-the-board U.S. defense spending cuts, it is not unreasonable to forecast a return to a more predictable budget cycle starting in 2015.
Pearce said Inmarsat is banking on the fact that a U.S. Defense Department operating with fewer resources will be more likely to use the kinds of services proposed by Global Xpress.