U.S. launches its highest capacity military communications satellite
CAPE CANAVERAL — An antenna-covered communications spacecraft that will bring more bandwidth and capacity to the U.S. military’s global information grid than any single satellite ever before was successfully launched Wednesday atop a Delta 4 rocket.
United Launch Alliance delivered the Wideband Global SATCOM satellite No. 8 into space for the U.S. Air Force following a 42-minute flight of the powerful rocket.
The two-stage Delta 4 was fueled during an uneventful afternoon countdown, then lit its hydrogen-fed main engine and four side-mounted solid-propellant boosters to depart Cape Canaveral right on schedule at 6:53 p.m. EST (2353 GMT).
Two burns of the cryogenic upper stage achieved a highly elliptical super-synchronous orbit stretching more than 27,000 statute miles in altitude, releasing the 13,000-pound payload while flying above the western Indian Ocean, just off the coast of Madagascar.
It marked the 107th successful launch in a row for the Delta program since 1999, the 360th success overall since 1960 and the 34th for a Delta 4.
United Launch Alliance also extended its mission record to 114 and completed its 45th mission for the Air Force in the past 120 months.
“As a former airman, I truly understand the importance of delivering national assets like the WGS 8 satellite to orbit safely,” said Laura McGinnis, United Launch Alliance’s vice president for Custom Services.
“We are proud of our partnership with the Air Force and proud to be entrusted by them to again deliver one of our nation’s most critical assets to orbit.”
Built by The Boeing Co., this latest WGS satellite features a technology advancement — the first Wideband Digital Channelizer at the heart of its communications package — that nearly doubles its capacity compared to the previous sister-spacecraft in the series.
“The channelizer on WGS 8 essentially performs the same function as WGS 1 through 7. It is a router in orbit. It basically takes radio frequency input from the ground, converts that to digital and then is able to route and move things around,” said Rico Attanasio, director of Boeing’s MILSATCOM programs.
“On WGS 8, we were able to transition the channelizer from its predecessor to the next-generation ASIC technology…provided by IBM to us. That improved our processing capability on board the spacecraft and we were able to open up more availability and routes of information through that router. By opening up those additional routes, we provided additional flexibility and more available bandwidth to the user.”
A single WGS satellite can support data processing at 6 gigabits per second, and WGS 8 with its advanced channelizer will support over 11 Gbps, officials said.
The WGS 8 satellite is valued at $426 million, including the new channelizer for the capacity upgrade.
All of that extra bandwidth can be utilized by any user within the satellite’s footprint.
“The capacity is available to any tactical warfighter and it’s up to the operators, who are the Army, to assign the use of bandwidth. That’s exactly the same (way) that we utilize WGS 1 through 7,” said Charlotte Gerhart, the Air Force’s WGS 8 program manager.
“So we’re simply making more bandwidth available and it will go to the users who are in that area. There’s no specific user who is targeted and there’s no specific area. Wherever WGS 8 is and whatever capacity is requested, the system will provide it.”
WGS is the backbone of the military’s global communications infrastructure for troops on the ground, aircraft in the sky, ships at sea, the White House Communications Agency and the State Department.
The system transmits high-priority communications such as the exchange of war-fighting information between battlefield commanders on the ground and senior defense officials.
“The WGS constellation provides wideband communications to Soldiers, Sailors, Airmen and Marines and international partners (for) broadcast, multicast and point-to-point connections anytime, anywhere around the world,” said Thomas Becht, civilian deputy director and business manager for the Air Force’s Military Satellite Communications Systems Directorate at the Space and Missile Systems Center in Los Angeles.
“WGS is unique among military satellites because it can simultaneously support X- and Ka-band communications and seamlessly connect the two bands.”
WGS uses the Boeing 702HP satellite design, which includes a xenon-ion propulsion system, highly efficient triple-junction gallium arsenide solar cells and deployable radiators with flexible heat pipes.
The WGS satellites place shaped, steerable spotbeams of bandwidth wherever requested across its field-of-view for Ka- and X-band frequencies, plus the onboard capability to switch signals from one band to the other.
Each satellite has electrically-steerable, phased array antennas for X-band transmitting and receiving, mechanically-steered Ka-band antennas and a fixed full-Earth-coverage beam also in X-band.
The antennas provide 19 independent coverage areas — 10 Ka-band and 8 X-band spotbeams, plus the full-Earth footprint.
WGS 8 will spend the next three months being maneuvered from its current transfer orbit into a circular one by controllers at Boeing’s satellite facility in El Segundo, California. The orbit raising activities will use both conventional hydrazine engines as well as ion propulsion thrusters.
Boeing will oversee the craft’s solar array and antenna deployments, plus complete an initial round of testing before WGS 8 is handed over to the Air Force for its own round of checkouts and final positioning in orbit.
The solar arrays will stretch 135 feet tip-to-tip, a wingspan larger than a Boeing 737 but smaller than a Boeing 747.
This satellite will operate at a yet-undisclosed location in geostationary orbit 22,300 miles above the equator, matching Earth’s rotation and remaining in lockstep over a specific spot of the globe.
“The information age has resulted in an explosion of communications demand capability for everyone globally. And for our armed forces and DOD users, wideband communications is vitally important to executing missions that defend and protect the people of the United States and our interests. More and more, WGS is called upon to deliver reliable, high-data-rate communications anywhere in the world, sometimes in contested environments,” said Attanasio.
“In addition to the technical advancements made on WGS 8, the entire WGS system is currently undergoing resilience upgrades that are being enabled across the fleet to better protect communications from interference and signal jamming.”
Those upgrades have involved uplinking new operating software to the orbiting satellites and modifying the ground segment. And the phased arrays enable operators shape the beams and control power to avoid intentional or accidental interference.
The first five WGS satellites formed a constellation for global coverage. The subsequent spacecraft have beefed up and expanded capacity of the network with overlapping orbital slots.
Two more WGS craft, each carrying the upgraded channelizer, will be launched by Delta 4 rockets in the next two years to punctuate the constellation.
WGS 9, built by international funding from Canada, Denmark, the Netherlands, Luxembourg and New Zealand, is preparing for shipment from its Los Angeles factory to Cape Canaveral for launch in March.
The allies bought the satellite in exchange for access to the entire constellation, similar to the groundbreaking deal with Australia that paid for the construction and launch of WGS 6.
“In accordance with the terms of the partnership, the international partners gained access to the WGS constellation upon enactment in 2012,” said Lt. Gen. Samuel Greaves, the Air Force’s program executive officer for space.
The final satellite — WGS 10 — has been manufactured and will soon start system-level testing for a late 2018 liftoff aboard the last “single-stick” Delta 4-Medium+ vehicle.
“You only need to look at the headlines today to see the events that will continue our military’s engagement across the globe. The enhancement of the WGS constellation will ensure that the U.S. and its allies can meet their committments,” said Walt Lauderdale, the WGS 8 launch vehicle lead and the technical director of the EELV generation and operations division within the Air Force’s Launch Systems Enterprise Directorate at the Space and Missile Systems Center in Los Angeles.
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8 Dec, 2016
U.S. launches its highest capacity military communications satellite
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