The United States launch alliance will withdraw its rocket family on Thursday with the final flight of a "single stick" configuration of the Delta 4 rocket, a mission set to take off from Cape Canaveral, carrying a new GPS satellite to orbit the US air force.
The 29th and final Delta 4-lane flight is scheduled to take off from launch at Cape Canaveral Complex 37 at 9am. EDT (1300: 30 GMT) on Thursday. The launch window runs until 9:27 pm. EDT.
Already the window to start Thursday has an 80% chance of a favorable time.
ULA cancels Delta 4-Mid as the company faces fierce competition from Space for US military launch contracts. The new Vulcan Centaur rocket, set for inaugural launch in 2021, will be cheaper than the Atlas and Delta rockets it replaces.
The Delta 4-heavy rocket, made by combining three first-phase cores together, will continue to fly until 2023. ULA's Atlas 5 rockets, which cost less than Delta 4, will also remain operational during the early to mid-2020s.
"We made a business decision a few years ago that we would move from Delta 4 and Atlas vehicles to Volcano Centaur, designed to meet the full mission package, so it's time to use Delta 4-. Midway through the moment, "said Gary Wenz, vice president of government and KLA commercial programs, in a press briefing before launch. "We do not see specific loads that require a Delta 4 medium that we cannot fly on the Atlas 5."
The Delta 4 launcher was originally designed and developed by Boeing. Atlas 5 was conceived by Lockheed Martin.
Competing aerospace contractors merged their launch departments in 2006, marking the birth of ULA as a 50-50 joint venture.
The ULA launch team will load super cold liquid hydrogen and liquid oxygen into the two-phase Delta 4 rocket during the countdown on Thursday morning.
Cryogenic fuels will feed the main phase RS-68A engine and the second phase RL10 engine. Both plants are manufactured by Aerojet Rockets.
The Delta 4 launch on Thursday will fly in the 4.2 configuration with a 4-meter 4-meter payload and solid rocket reinforcement diameter, developed by innovative Northrop Grumman systems.
The basic engine RS-68A will start in T-minus for 5 seconds and will be activated for computer health check. Assuming all systems are ready, the side mounted solid fuel boosters will ignite when the clock count reaches zero to push the Delta 4 into the sky.
The main engine and solid rocket amplifiers will generate about 1.2 million pounds of combined progress. The RS-68A motor jet nozzles and double straps will drive the Delta 4 on the northwest trajectory approximately parallel to the US east coast.
The launcher will exceed the speed of sound in less than a minute, and both 53-meter (16-meter) rocket boosters will burn and burn andethisone at T + plus 1 minute, 40 seconds.
The RS-68's core engine will shut off at T + plus for 3 minutes, 55 seconds, followed by a split phase approximately seven seconds later. The Delta upper phase RL10 engine, also built by Aerojet Rockets, will light the first of two fires needed to set the GPS satellite in elliptical transfer orbit.
The Delta 4 cargo configuration will appear in T-shaped wheel shape plus 4 minutes, 26 seconds, after the rocket soars into the upper atmosphere of the upper atmosphere. The roof protects the GPS load during launch preparations and climbs through the lower layers of the atmosphere.
The upstream RL10 engine will shut off at T + plus 13 minutes, 33 seconds to reach preliminary orbit. The RL10 engine restart is planned nearly 67 minutes after the abolition of a three-and-a-half-minute combustion engine for the GPS spacecraft into the egg-shaped transfer orbit, which runs between 745 miles (1,200 km) and 12,542 miles (20,185 km). ) above the Earth, with the orbital plane inclined 55 degrees to the equator.
The GPS satellite built at Lockheed Martin will be separated from the Delta 4 launcher on T + plus 1 hour 55 minutes.
The satellite navigation GPS 3 SV02, nicknamed "Magellan", will use its own engine to orbit its satellite and join the GPS constellation about 12,550 miles above the planet, where ground crews will test the new aircraft and put it in use to replace the aging member of the constellation.
The GPS network provides worldwide positioning and timing services for military and civilian users, illuminating signals relied on by airlines, ATMs, drivers and smart bombs, among many other users.
"We are committed to maintaining GPS as the gold standard for positioning, navigation and timing for all other systems to be measured," said Col. Maggie Sullivan, GPS Air Force Program Manager 3.
Thirty-one satellites currently provide GPS navigation services.
Thursday's satellite launch kit is the second in a new generation of GPS satellites, providing accurate navigation signals and boasting a longer design life. The new GPS 3 satellites provide a new L1C citizen signal that is compatible with the Galileo network in Europe.
Other space-based navigation networks operated by Japan and China also receive similar compatible signals.
"Compared to satellites in today's constellation, this next-generation GPS satellites have three times more accuracy, eight times better anti-jam enhancements, and a new L1C citizen signal compatible with other international satellite navigation systems such as Galileo," said Athonathan Cauldevelt for navigating Lockheed Martin.
"For those users of equipment (suppliers) who choose to embed the L1C citizen signal into their chips, those users will now have access not only to the GPS constellation, but to Galileo and others who choose to continue with the implementation of the L1C citizen signal, Caldwell said. "So for users who are empowered to do so, instead of just inheriting the 31 points in the sky you get from GPS, you will add to it the ever-growing Galileo constellation.
"When it comes to finding out where you are, the more satellites you can see the better your position."
The first 3-series GPS satellite, named GPS 3 SV01, completed its launch after launching on July 12, following the deployment of the SpaceX Falcon 9 rocket target last December, officials said. More testing is planned before the GPS 3 SV01, called Vespucci, is ready to join the active GPS network.
"We are now excited that the vehicle is going through the orbital outcome and is moving to the next phase of operational testing," Caldwell said. "We expect to start later this year and look forward to officially handing the vehicle over to the Air Force."
Like the previous line of satellites embedded with GPS 2F, Boeing, the GPS 3 Series GPS spacecraft will emit a dedicated L5 signal intended to support air navigation. GPS 3 satellites also carry a bundle of encrypted military-grade navigation signal known as M-code.
The M-code signal allows GPS satellites to transmit more power, jam-resistant, signals to certain regions, such as a theater or battlefield. The capability enables the United States and Allied forces to have more reliable navigation services, and can also allow the military to deliberately disrupt or jam civilian GPS signals in a given region, while the M-code signal remains unbroken.
L3Harris Technologies builds navigation loads for GPS 3 satellites.
Thursday's launch is slated to be incorporated into the GPS 3 SV02 spacecraft in Plane D, Slot 3 with the GPS console. That position is currently occupied by GPS satellite, launched in March 2003. Sullivan said the Air Force would make an "operational decision" that an aging GPS satellite, likely on Plane D, would replace the new spacecraft.
GPS satellites are distributed among six orbital planes, each with four basic aircraft, plus spare parts.
According to Sullivan, the GPS 3 SV02 spacecraft cost about $ 500 million. Future GPS 3 satellites will cost less, and officials are aiming for less than $ 200 million per spacecraft as the GPS 3 SV10 is ready to launch.
"The best thing about GPS is the volume of satellites," Caldwell said. "You get huge efficiency when you have a production volume and you get a proportionate reduction in costs."
Lockheed Martin has contracted with the Air Force to build up to 32 satellites, including 10 GPS 3 spacecraft and 22 upgraded GPS 3F satellites.
The next GPS mission, designated GPS 3 SV03 and nicknamed Columbus, is set to launch the SpaceX Falcon 9 rocket in January. The satellite for that mission has already been made available for launch, Air Force officials said.
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