Upgraded satellite for communications among U.S. military forces ready to launch
CAPE CANAVERAL — The backbone of the U.S. military’s global communications network, relied upon by soldiers, ships, jets, aerial drones and allied nations around the world, will receive a new satellite with unprecedented capacity following its launch Wednesday atop a Delta 4 rocket.
The Wideband Global SATCOM satellite No. 8, a $426 million investment by the Pentagon and built by Boeing, will be boosted into space by the United Launch Alliance rocket from Complex 37 at Cape Canaveral.
Liftoff is planned for 6:53 p.m. EST, the opening of a 49-minute launch window that extends to 7:42 p.m. EST (2353-0042 GMT).
Weather forecasters predict an 80 percent chance of favorable conditions for the launch. They are calling for broken low-level and high cloudiness, good visibility, light northwesterly winds and a temperature of 69 degrees F.
The 900,000-pound, 217-foot-tall rocket will launch atop 1.8 million pounds of thrust from its hydrogen-fueled Aerojet Rocketdyne RS-68A main engine and four side-mounted solid-fuel boosters from Orbital ATK.
The cryogenic upper stage will fire its Aerojet Rocketdyne RL10B-2 engine twice, achieving a highly elliptical super-synchronous transfer orbit stretching 27,500 statute miles, and then release the 13,000-pound satellite almost 42 minutes after liftoff.
The satellite will operate at an 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.
WGS is the essential element of our military’s ability to communicate, providing the flow of information “anytime, anywhere” around the world.
It is the Defense Department’s primary network, while other satellites serve specialized needs like the Air Force’s nuclear-survivable, protected communications on the AEHF satellites and the Navy’s mobile system with MUOS.
WGS is a 10-satellite constellation that began launching in 2007 and will see its final member deployed in 2018, blanketing the entire planet with communications coverage for all branches of the U.S. military, the White House and State Department, plus Australia, Canada, Denmark, the Netherlands, Luxembourg and New Zealand.
“At Boeing, we’re especially proud to look ahead to our eighth WGS launch, providing mission-critical broadband military satellite communications to the U.S. and allied partners,” said Rico Attanasio, director of Boeing’s MILSATCOM programs.
What’s more, WGS 8 carries the first Wideband Digital Channelizer at the heart of its communications package, enabling a 90 percent improvement in available bandwidth compared previous WGS satellites.
“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 Attanasio.
“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 satellites supply communications such as maps and data to soldiers on the battlefield, relay video from unmanned aerial reconnaissance drones, route voice calls and messaging, and even offer quality-of-life considerations like television broadcasts and email delivery to the troops.
Supporting both X- and Ka-band communications, WGS spacecraft are the Department of Defense’s highest capacity communications satellites.
“Although WGS is commercial-like, WGS is very much a military satellite with military-unique requirements and capabilities such as flexible routing, shapeable X-band coverage to combat enemy jamming, steerable spot beams to track mobile users and cross-banding between X- and Ka-bands,” said Attanasio.
WGS also supports the military’s Global Broadcast Service.
“It kind of like the DirecTV of the DOD. It broadcasts (anything) from unclassified, in-the-clear signals all the way up to classified out to the warfighter and has the capability of going pretty much to any platform or even troops in the field. The WGS system is the backbone for getting the signal out to the warfighter,” 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 1 was launched in October 2007 to cover the vast U.S. Pacific Command that stretches from the U.S. western coast all the way to Southeast Asia.
WGS 2 satellite followed with an April 2009 launch to serve U.S. Central Command and the forces in Afghanistan, Iraq and other parts of Southwest Asia.
WGS 3 went up in December 2009 to cover U.S. European Command and U.S. Africa Command, plus lend additional support over the Middle East.
WGS 4 inaugurated the upgraded Block 2 series for improved communications with unmanned aerial drones when it was launched in January 2012 to cover the Middle East and Southeast Asia for use by U.S. Central Command and U.S. Pacific Command.
WGS 5 extended the Wideband Global SATCOM constellation to the Americas for a host of users following launch in May 2013. It gives the CONUS coverage to U.S. Northern Command, Southern Command, Transportation Command, Strategic Command, the Missile Defense Agency and other U.S. and western hemisphere-based users.
WGS 6 was launched in August 2013 and serves as Australia’s contribution to the Wideband Global SATCOM constellation. It was built and launched via Australian funding in exchange for its military getting a percentage of communications services through the global constellation. The craft is parked over the eastern Pacific for coverage of the Americas.
WGS 7 was launched in July 2015 to further fortify the military’s “anytime, anywhere” communications infrastructure, adding to the global WGS system from its position above the western Pacific with a coverage area spanning the Middle East, Southeast Asia and Australia.
The WGS 8 launch comes a week after United Launch Alliance marked its 10th anniversary. On Dec. 1, 2006, ULA was formed to blend the once-rival Atlas and Delta rocket families together, creating a more efficient way to manage, design, build and launch the boosters carrying the U.S. government’s most critical payloads, and the company has performed 113 launches in 120 months, all successfully. Here’s some statistics:
**UNITED LAUNCH ALLIANCE** VEHICLE....LAUNCHES Atlas 5..........59 Delta 2..........28 Delta 4..........26 CUSTOMER Air Force........44 NASA.............27 NRO..............23 Commercial.......19 LAUNCH SITE Cape Canaveral...81 Vandenberg AFB...32
If the WGS 8 launch is delayed for some reason, the daily window remains nearly unchanged.
Dec. 7...6:53-7:42 p.m. EST Dec. 8...6:54-7:43 p.m. EST Dec. 9...6:54-7:43 p.m. EST
Arcing to the east on a 93.46-degree flight azimuth, Delta 4 will experience maximum dynamic pressure, or Max Q, at 46 seconds, and the ground-lit boosters will burn out at 92 seconds and separate at 100 seconds.
Once out of the atmosphere and shortly before staging, the 47-foot-tall, 17-foot-diameter nose cone made of composites is jettisoned three minutes and 14 seconds into flight.
The first stage engine will propel the vehicle until T+plus 3 minutes and 56 seconds, followed by separation of the Common Booster Core six seconds after cutoff.
The initial burn by the upper stage gets underway at T+plus 4 minutes, 15 seconds, firing the high-energy RL10 engine for nearly 16 minutes to accelerate to orbital velocity and then reach a preliminary parking orbit.
The vehicle then performs a brief coast above equatorial Africa before restarting the RL10 engine at T+plus 29 minutes, 27 seconds, executing a three-minute burn to reach a highly elliptical super-synchronous transfer orbit.
Spacecraft deployment occurs over the Indian Ocean at T+plus 41 minutes, 44 seconds.
WGS 8 will be released into an orbit 270 by 27,575 statute miles with an inclination of 27 degrees. That orbit is lower than the 41,000-mile apogees achieved by previous WGS satellites, a change was made to enable a safe deorbiting of the depleted upper stage after separating the satellite.
The new parameters meet the satellite’s requirements and allow for the disposal of the rocket body in the fight against space debris and uncontrolled re-entries, officials say.
It is a new policy for military launches to avoid leaving upper stages in orbit whenever possible. An extra strap-on solid rocket booster has been added to the Atlas 5 launching the SBIRS GEO Flight 4 missile-warning satellite in late 2017, for example, to give enough vehicle performance to complete the satellite deployment and then deorbit the upper stage.
Striving for a successful launch of the Delta 4, the Air Force, in its mission assurance role, has completed 148 hardware pedigree reviews, data package reviews for an additional 369 hardware items, 105 launch vehicle verification tasks and validated 105 rocket-to-satellite interface requirements.
“We never forget each rocket is unique…It is the clear focus on the individual rocket that ensures we never put the life of our customer — the satellite — at undue risk,” 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.
It will be the 34th Delta 4 rocket launch since 2002, the 19th mission for the Air Force and the sixth Medium+ (5,4) version of the vehicle to fly.
And it marks the 36th launch from Pad B at Complex 37, following 8 unmanned Saturn missions between 1964 and 1968 and 28 Delta 4s since 2002.
“We are ready for this mission, the last of seven National Security Space launches this year,” Lauderdale said.
See earlier Delta 376 coverage.
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5 Dec, 2016
Upgraded satellite for communications among U.S. military forces ready to launch
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