Boeing in late December successfully integrated the satellite bus and payload module for the fourth of six Wideband Global SATCOM (WGS) satellites the company is building for the U.S. Air Force.

WGS-4's broadband communications payload was mated with a high-power Boeing 702 platform at the company's Satellite Development Center in El Segundo, the world's largest satellite-manufacturing facility. Over the next few months, the WGS team will conduct final integration activities followed by rigorous environmental testing, including vibration and thermal-vacuum tests.

"With the mating of these modules, all bus and payload equipment for WGS-4 has completed integration and testing," said Craig Cooning, vice president and general manager, Boeing Space and Intelligence Systems. "This milestone capped a great year for the WGS program, which included launching two satellites less than eight months apart. The WGS team continues to perform at the highest levels and maintain its strong momentum."

WGS is the U.S. Department of Defense's highest-capacity communications satellite system, providing fast, flexible, broadband communications for U.S. warfighters and their allies around the world. WGS-4 is the first of three satellites to be built under the Block II contract. The Block II satellites include performance-boosting enhancements such as a radio frequency bypass designed to support airborne intelligence, surveillance and reconnaissance platforms requiring additional bandwidth. WGS-4, -5 and -6 are scheduled to launch in 2011 or 2012.

WGS-1 and WGS-2, launched in October 2007 and April 2009, respectively, have been accepted into service and are meeting or exceeding all mission requirements. WGS-3, launched in December, is undergoing on-orbit testing and is expected to go into service in April.

WGS satellites are built on the proven Boeing 702 platform, which uses a highly efficient xenon-ion propulsion capability. The communications payload provides reconfigurable coverage areas and the ability to connect X-band and Ka-band users anywhere within the satellite's field of view via an onboard digital channelizer - features that enhance security and mission flexibility, and are not available on any other communications satellite.