Friday, October 12, 2007

WGS Military Comm Sat Launched

The U.S. Air Force launched the first of a next generation of military communications satellites from here Oct. 10 at 8:22 p.m. (EDT), when a United Launch Alliance Atlas V booster carried a Wideband Global SATCOM satellite into space. Here are the particulars:

Name: Wideband Global Satcom (WGS)
Launch date/time: 11 October 2007 at 0022 UTC
Site: Air Force Eastern Test Range, Florida, USA
Launch Vehicle: Atlas V
International Designator: 2007-046A
SSC #: 32258
Owner: US

General Characteristics:
Primary Function: High-capacity military communications satellite
Primary Contractor: Boeing Satellite Development Center
Satellite Bus: Boeing 702
Weight: Approximately 13,000 lbs at launch, 7,600 lbs on-orbit
Orbit Altitude: 22,300 miles
Payload: Transponded, cross-banded-X and Ka-band communications suite
Antennas: 8 beam, transmit and receive X-band Phased arrays and 10 Ka-band Gimbaled Dish Antennas, 1 X-band Earth coverage
Capability: 39 125-MHz Channels via digital channelizer/router
Number of Terminals Supported: 92
Inventory: 5 on contract
Unit Cost: Approximately $350 million

WGS is the nation's next-generation wideband satellite communications system. It will augment and eventually replace the aging Defense Satellite Communication System which has been the Department of Defense's backbone for satellite communications over the last two decades.

"I am extremely proud of the hard work and dedication of the launch team in working the long hours that have brought us to where we are today," said Col. Donald Robbins, Commander, Wideband SATCOM Group, MILSATCOM Systems Wing.

"With the launch of WGS SV-1, we are on the cusp of providing more capacity than the entire on-orbit Defense Satellite Communications System constellation."

With the launch of SV-1, WGS SV-2 and SV-3 will round out the remainder of the Block I contract. Both satellites are currently progressing through their test programs and are slated for launch next year. The WGS Block II contract for SV-4 and SV-5 was awarded last year. The WGS system is being procured through a commercial contract with the Boeing Company by the Wideband SATCOM Group, part of the MILSATCOM Systems Wing.

WGS will enable enhanced and more flexible execution of Command and Control, Communications Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), battle management, and combat support information. WGS will also augment the existing service available on the UHF F/O satellites by providing additional information broadcast capabilities via Global Broadcast Series (GBS).'

The WGS SV-1 spacecraft (SC) is an approximately 12,718-lb communications satellite. WGS supports communications links in the 500 MHz range of the X-band and 1 GHz range of the Ka-band spectra. WGS can filter and route up to 4.875 GHz of instantaneous bandwidth. Depending on the mix of ground terminals, data rates, and modulation schemes employed, a WGS satellite can support data transmission rates between 2.4 and 3.6 Gbps.

WGS has 19 independent coverage areas that can be positioned throughout its field of view. This includes eight steerable/shapeable X-band beams formed by separate transmit/receive phased arrays; 10 Ka-band beams served by independently steerable diplexed antennas (three with selectable RF polarization); and transmit/receive X-band Earth-coverage beams. WGS can tailor coverage areas and connect X-band and Ka-band users anywhere within its field of view.

Command and Control of WGS is accomplished from four Army Wideband Satellite Operations Centers (WSOCs). Each Global SATCOM Configuration and Control Element (GSCCE) has the capability to control up to three satellites at a time, using X-band or Ka-band telemetry and command links. Spacecraft platform control will be accomplished by the 3rd Space Operations Squadron (3 SOPS) at Schriever AFB in Colorado Springs, CO using WGS mission-unique software and databases.

Support technologies for WGS include the xenon-ion propulsion system (XIPS), highly efficient triple-junction gallium arsenide solar cells, and deployable radiators with flexible heat pipes. The XIPS is 10 times more efficient than conventional bipropellant systems. Four 25-cm thrusters remove orbit eccentricity during transfer orbit operations.

The thrusters are also used to perform orbit maintenance and any required station-change maneuvers during the mission life. The triple-junction gallium arsenide solar cells provide on-orbit electrical power for the spacecraft. The deployable radiators? flexible heat pipes provide increased radiator area; resulting in a cooler, more stable thermal environment for the spacecraft.

Built by the Boeing Satellite Development Center, WGS will provide essential communications services for Combatant Commanders to command and control their tactical forces. Tactical forces will rely on WGS to provide high-capacity connectivity into the terrestrial portion of the Defense Information Systems Network (DISN).

'After final checkout and turnover of SV-1, we will have doubled the available high-capacity Military Satellite Communications services,' said Col. Donald Robbins, Commander, Wideband SATCOM Group, MILSATCOM Systems Wing.

Upon its first launch into geosynchronous orbit in 2007, WGS SV-1 will be the Department of Defense's highest capacity communications satellite. A constellation of five satellites will provide service in both the X and Ka-band frequency spectrums.

The first three WGS satellites will be launched in 2007 and 2008. Both the Delta IV and Atlas V Evolved Expendable Launch Vehicles (EELV) will be used. Satellites 4 and 5 are anticipated for launch in 2011 and 2012.

The Space and Missile Systems Center, located at Los Angeles Air Force Base, Calif., is the U.S. Air Force's center of acquisition excellence for acquiring and developing military space systems including six wings and three groups responsible for GPS, military satellite communications, defense meteorological satellites, space launch and range systems, satellite control network, space based infrared systems, intercontinental ballistic missile systems and space situational awareness capabilities. SMC manages more than $60 billion in contracts, executes annual budgets of $10 billion and employs more than 6,800 people worldwide.