Home / Science / Delta 4 rocket launches Air Force's 10th WGS broadband satellite – Spaceflight Now

Delta 4 rocket launches Air Force's 10th WGS broadband satellite – Spaceflight Now



A United Launch Alliance Delta 4 rocket takes off from Cape Canaveral Air Force Station, Florida, on Friday with the US Air Force's 10th Wideband Global SATCOM communications satellite. Credit: Walter Scriptunas II / Spaceflight Now

United Launch Alliance put a new satellite in circulation with a fiery Friday night from Cape Canaveral, with a version of the Delta 4 rocket approaching retirement to complement a US military network from drones and battlefield commanders.

After the ground cleared several technical barriers with rocket and a satellite tracking network, the 218-foot (66 meter) Delta 4 launch fuel-fueled RS-68A main engine flashed to life with an orange burst of flame moments before liftoff.

Five seconds later, four solid rocket engines and bolts were released at 8:26 EDT Friday (0026 GMT Saturday) when the Delta 4 quickly climbed from Cape Canaveral's complex 37B launch pad with 1.8 million pounds of shock.

The main engine and booster nozzles dared to drive the Delta 4 east across the Atlantic, sending the US Air Force's tenth Wideband Global SATCOM communications satellite toward its final operating position more than 22,000 miles across the equator in geostationary orbit.

Delta 4's solid rocket boosters, built by Northrop Grumman, burned out and jettisoned in two pairs around 1 minute, 40 seconds, in the mission. Once above the atmospheric dense lower layer, Delta 4 released its nose to reveal the WGS 10 satellite.

Aerojet Rocketdyne RS-68A main engine fired nearly four minutes until the first step was released to fall into the Atlantic. An upper radius RL10B-2 engine, also supplied by Aerojet Rocketdyne, was lit twice to accommodate the WGS 10 spacecraft to an elliptical transmission path that extends no more than 27,500 miles (44,300 kilometers) above the ground.

The Boeing-built WGS 10 satellite separated from the Delta 4's top stage on T + plus 36 minutes, 50 seconds, extending the company's strike of successful missions to 133 since its inception in 2006. [W65]. Credit: Boeing

Friday night's launch was delayed 90 minutes to give engineers the opportunity to investigate technical problems in the first and second stages of the Delta 4 rocket. When these issues were completed, the launch team had to wait for officials to ensure that NASA's tracking and data help satellite system was ready to move rocket telemetry to ground control.

The assignment marked the closest flight of Delta 4 rocket variants with a single first-stage core – known as Delta 4-Medium – which ULA begins to depart segment of its starting family in preparation for the debut of the new Vulcan booster that the company says is cheaper than the existing Atlas and Delta fleet.

Gary Wentz, ULA's vice president of government and commercial programs, said the company's decision to retire for Delta 4-Medium in 2014 was intended to reduce the company's costs.

"We started looking at products we provided, and found that the maintenance of these two families of starter vehicles, both Delta and Atlas, during this period reduced our flight speed and thus increased our costs" Wen tz said. "It really ran it, based on the competitive industry we are in, and trying to maximize our competitiveness."

The Delta 4 Medium family offers the same range of lifting capacity as the cheaper Atlas 5 rocket. Delta 4-Heavy, which will remain operational through at least early to the mid-2020s, uses three Delta 4 cores in the first step which are bolted together to draw heavier payloads in circulation than any of the Atlas 5 configurations.

ULA was formed in 2006 through the merger of Boeing's Delta 4 and Lockheed Martin's Atlas rocket program. The 50-50 joint venture retained both rocket lines to ensure that the US military had two independent launch options for national security satellites.

But SpaceX's Falcon 9 and Falcon Heavy rockets are now certified to launch US security loads. With the Falcon and Atlas rocket families, the military continues to have two launch options after the Delta 4-Mediums retirement. The Delta 4 rocket strings drop in this long exposure photo. Credit: Alex Polimeni / Spaceflight Now

Friday's launch used the Delta 4-Medium + 5.4 rocket variant, with four solid rocket boosters and a 5.1 meter (16.7 feet) upper stage and payload. It was the eighth and final flight of the Delta 4 Medium + 5.4 configuration, and all had WGS satellites for the Air Force.

An additional Delta 4-Medium rocket is set for launch July 25 from Cape Canaveral with an air force GPS navigation satellite. The launch will fly in the Delta 4 Medium + 4.2 configuration, with two solid rocket amplifiers and a 4 meter (13.1 foot) diameter top stage and payload.

With Friday's launch, the Delta 4 rocket has flown 39 times since November 2002 and 28 of these missions used a Delta 4 Medium.

"It has had a very successful history, and it is similar to the WGS satellite, it is a workhorse for the Air Force," Wentz said of Delta 4-Medium. "It's kind of bittersweet that we're here at the end, but we look forward to the missions that come in the future and the vehicles that we will field".

Including the GPS launch in July, ULA has contracted for six Delta 4 flights by 2024. The five Delta 4 Heavy launches scheduled in the early 2020s will all hold top secret payloads for the National Reconnaissance Office, US government spy agency:

  • Delta 4-Medium + 4, 2 with GPS 3 SV02 payload
    • Starting date: July 25, 2019
    • Launch site: SLC-37B, Cape Canaveral Air Force Station, Florida
  • Delta 4-Heavy with NROL-44 payload
    • Starting date: 2020
    • Starting site: SLC-37B, Cape Canaveral Air Force Station, Florida
  • Delta 4-Heavy with NROL-82 payload
    • Starting date: 2020
    • Starting site: SLC-6, Vandenberg Air Force Base, California
  • Delta 4-Heavy with NROL-91 payload
    • Starting date: Financial year 2022
    • Starting place: SLC-6, Vandenberg's Air Force Base, California
  • Delta 4-Heavy with NROL-68 payload
    • Starting date: Fiscal year 2023
    • Starting site: SLC-37B, Cape Canaveral Air Force Station, Florida
  • Delta 4-Heavy with NROL-70 payload
    • Starting date: Fiscal year 2024
    • Starting website: SLC-37B, Cape Canaveral Air Force Station, Florida

13,200-pound (6 000 kilos) WGS 10 communications satellite launched Friday night connects nine broadband satellites that have been implemented since 2007 to form a worldwide network relay video, data and other information between the battlefield to decision makers.

The WGS fleet transfers classified and unclassified signals, which support US and Allied forces around the world. With a digital channel, the approximately $ 400 million WGS satellite will relay high-data communications in X-band and Ka-band frequencies during a mission expected to be at least 14 years.

One of the WGS 10 satellite Ka band reflectors during an expansion test inside the Boeing factory in El Segundo, California. Credit: Boeing

"WGS has the unique ability to cross-link between military Ka and X bands, giving our war fighters a great flexibility to maximize communication capability," says Tom Becht, director of the military satellite communications directorate at Air Force Space and Missile. Systems Center in Los Angeles.

The nine former WGS satellites were launched on ULA rockets – the first two at Atlas 5s 2007 and 2009 and the following seven at Delta 4s. Wideband Global SATCOM fleet is the United States Defense Department's highest satellite communications network capability.

Two of the 10 WGS satellites launched so far were funded by international governments. WGS 6 was funded by Australia and a consortium including Canada, Denmark, Luxembourg, the Netherlands and New Zealand paid for the WGS 9 satellite launched in March 2017. Unlike their contributions, the national military gets access to the WGS network.

WGS 10 is the fourth and last "Block II Follow-On" WGS satellite, and it is the third with the digital channel, which handles communication signals more effectively, almost doubling the bandwidth of previous spacecraft in the series. [19659003] Based on the Boeing 702 satellite platform, WGS 10 will use a liquid-based boost engine and plasma screws to circulate its path more than 22,000 miles across the equator. The maneuvers will take about four months, officials said before WGS 10 reaches geostationary orbit, where its speed will match the degree of Earth's rotation.

After a two-month test of geostationary orbit over the United States, military leaders will decide where to install WGS 10.

Army Col. Enrique Costas, Defense Communications and Army Transmission Project Manager, said the WGS network is widely used in the military because of its reliability and high bandwidth capabilities, allowing live video broadcasts from drones around the world back to operators hundreds or thousands of miles away.

"If I were to target a particular terrorist in the Middle East, and I have an Intelligence, Surveillance and Reconnaissance ISR looking at that terrorist, I must be able to make a decision on whether to burn or send one

High definition video streaming from a flying drone requires a lot of bandwidth, he said.

"I have to be able to send that signal from the collection point all the way back to the center where the decision is to be made about not to pull the trigger or distribute a team to act on a particular mission, says Costas to journalists in a conference call before the launch. "WGS is one of the leading ISR operators for operating theaters in some theaters."

The White House and the State Department are also dependent on WGS satellites and the network broadcasts television signals to troops stationed around the world.

"If … I have a teleconfiguration between it (the combatant commander) and the US president, I want to make sure that the signal does not go down at any time during that conversation to make critical decisions," continued Costas. is part of that transportation to make sure we have reliable and secure communications, no matter where we are on the planet. "

The Air Force is close to awarding a new contract to Boeing for at least one additional WGS satellite. [19659003] Congress added 600 million dollars to the fiscal year 2018 defense budget for two new WGS satellites that rolled over the military's plans to start sourcing more communication capacity from commercial satellites, but the finance line did not include money to launch the satellites, each costing between 300 million and 400 million

The Air Force has kicked off another round of WGS procurement using unexpected money, and Boeing left one t proposal in January Military officials have not decided to order one or two WGS satellites, according to Becht. He said that a final decision and contract signature is expected later this year.

Becht said the Air Force could follow a purchasing model often used by commercial satellite operators, where Boeing would be responsible for building the new WGS spacecraft with more cost effective, efficient methods. Boeing can also choose a launch supplier for the new WGS spacecraft, which connects the entire mission with a fully turnkey contract, with final delivery of the satellite to the Air Force after it is in circulation.

"The WGS system's capabilities support our allies around the world in common missions and help our military become more efficient," said Rico Attanasio, Boeing's tactical communications director. "Moving forward, as the need for resilience in SATCOM grows, I am convinced that WGS continues to be an important element to meet the needs of secure protected communications. "

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Follow Stephen Clark on Twitter: @ StephenClark1 .


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