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52-689: The GEM 63 was developed by Orbital ATK as a low-cost drop-in replacement for the Aerojet Rocketdyne AJ-60A solid rocket booster used on the Atlas V. Its overall dimensions are very similar to that of the motor it replaces. The Atlas V first flew with the GEM 63 in 2020 on the NROL-101 launch. The booster offers higher performance at about half the cost of the AJ-60A boosters formerly used on

104-471: A Delta Cryogenic Second Stage (DCSS)) and a 4-meter payload fairing. The Delta IV Medium was capable of launching 4,200 kg to geostationary transfer orbit (GTO). From Cape Canaveral, GTO is 1804 m/s away from GEO. The mass of fairing and payload attach fittings have been subtracted from the gross performance. The Delta IV Medium+ (4,2) (Delta 9240) had the same CBC and DCSS as the Medium, but with

156-672: A 4 m (13 ft) diameter DCSS that was retired with the Delta IV Medium and a 5 m (16 ft) diameter DCSS that remains in service with the Delta IV Heavy. The 4 m diameter version lengthened both Delta III propellant tanks, while the 5-meter version has an extended diameter liquid hydrogen tank and a further lengthened liquid oxygen tank. Regardless of the diameter, each DCSS is powered by one RL10B-2 engine, with an extendable carbon-carbon nozzle to improve specific impulse. Two different interstages are used to mate

208-529: A Delta II (Delta 241) exploded due to a catastrophic failure in a GEM 40. The failure triggered the launch vehicle's self-destruct function 13 seconds after ignition. An Air Force investigation determined that the motor's casing had been damaged prior to launch, causing the case to split open soon after ignition. The GEM 46 was a 45.1-inch-diameter (1,150 mm) solid rocket motor originally developed for Delta III by Alliant Techsystems . This solid motor variant included thrust vector control (TVC) to help steer

260-472: A LEO payload of 14,800 kg (32,600 lb), and could have been available within 36 months of the first order. It was also considered to add extra GEM 60s to the M+ (5,4), which would have required adding extra attachment points, structural changes to cope with the different flight loads, and launch pad and infrastructure changes. The Medium+ (5,6) and (5,8) would have flown with six and eight SRBs respectively, for

312-481: A Payload Attach Fitting (240 kg to 1,221 kg depending on payload). Possible future upgrades for the Delta IV included adding extra strap-on solid motors, higher-thrust main engines, lighter materials, higher-thrust second stages, more (up to eight) strap-on CBCs, and a cryogenic propellant cross feed from strap on boosters to the common core. At one point, NASA planned to use Delta IV or Atlas V to launch

364-570: A division until January 1, 2020 when a reorganization merged the operations into the company's other divisions. A merger of Orbital Sciences Corporation and the defense and aerospace divisions of Alliant Techsystems (ATK) was announced on April 29, 2014. The two companies had collaborated on several previous projects, including the use of 400 ATK rocket motors in Orbital's launch vehicles. The deal officially closed on February 9, 2015. ATK's sporting-goods division spun off to form Vista Outdoor on

416-417: A higher degree of reliability. Boeing initially intended to market Delta IV commercial launch services. However, the Delta IV entered the space launch market when global capacity was already much higher than demand. Furthermore, as an unproven design it had difficulty finding a market in commercial launches, and Delta IV launch costs are higher than comparable vehicles of the same era. In 2003, Boeing pulled

468-522: A maximum of up to 9,200 kg (20,300 lb) to GTO with the M+ (5,8). The Medium+ (5,6) and (5,8) could have been available within 48 months of the first order. The Vulcan Centaur is planned to replace the Atlas V and Delta IV rockets. Vulcan Centaur had been projected to enter service by 2023, using the BE-4 methane -fueled rocket engine, but the first Vulcan launched on 8 January 2024. The Atlas V

520-635: A small variant was considered. This would have featured the Delta II second stage, an optional Thiokol Star 48B third stage, and the Delta II payload fairing, all atop a single Common Booster Core (CBC). The Small variant was dropped by 1999. In 2002, the Delta IV was first launched, with the RS-68 becoming the first large liquid-propellant rocket engine designed in the United States since

572-498: Is currently used on Vulcan Centaur rocket. A variant equipped with a thrust-vectoring nozzle, the GEM 63XLT, was under development for the cancelled OmegA launch vehicle. On 4 October 2024, a GEM 63XL experienced a partial failure 35 seconds after liftoff during the Vulcan Centaur Cert-2 mission. A change in the motor's plume as well as debris was observed falling from the motor after the anomaly. Observations of

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624-535: Is expected to stay in service for a few years after Vulcan's inaugural launch, and the Delta IV Heavy was discontinued in April 2024. The Delta IV Medium (also referred to as 'single stick' ) was available in four configurations: Medium, Medium+ (4,2), Medium+ (5,2), and Medium+ (5,4). The Delta IV Medium (Delta 9040) was the most basic Delta IV. It featured a single CBC and a modified Delta III second stage, with 4-meter liquid hydrogen and liquid oxygen tanks (called

676-772: Is used to air launch Pegasus rockets carrying payloads into space. The Stargazer aircraft is also used for testing under specific programs. The Flight Systems Group became part of Northrop Grumman Space Systems on January 1, 2020. The Defense Systems Group, based in the Baltimore, Maryland area, produces tactical missiles, defense electronics, and medium- and large-caliber ammunition. The division also produces fuzing and warheads for both tactical missiles and munitions; precision metal and composite structures for medium and large-caliber ammunition, military aircraft, ground vehicles, and missile systems; load, assembly, and pack (LAP) of medium caliber munitions; and propellants and powders for

728-499: The Ground-based Midcourse Defence anti-ballistic missile program, but GMD later switched to Orion-50 -based missile. On 5 August 1995, an air-lit GEM 40 failed to separate from a Delta II 7925 carrying Koreasat 1 . The excess mass of the booster resulted in the satellite reaching a lower orbit than intended. The satellite was able to correct for the error using on-board propellant. On 17 January 1997,

780-467: The Space Shuttle main engine (SSME) in the 1970s. The L3 Technologies Redundant Inertial Flight Control Assembly (RIFCA) guidance system originally used on the Delta IV was common to that carried on the Delta II , although the software was different because of the differences between the Delta II and Delta IV. The RIFCA featured six ring laser gyroscopes and accelerometers each, to provide

832-504: The 7000-series Delta II launch vehicle beginning in 1987 by Hercules . Its first flight took place in 1990 on the USA-66 mission, when 9 boosters were used on a Delta II 7925 launcher. The use of composite materials allowed for casings lighter than the steel casings of the Castor 4 SRMs they replaced. The reduction in weight was used to extend the GEM 40 by 5.9 feet (1.8 m) compared to

884-486: The Atlas V. The GEM 63XL, developed by Northrop Grumman, is an extended version of the GEM 63, about 73 inches (190 cm) longer than its predecessor. The weight is approximately 117,000 pounds (53 metric tons) each. First fired in 2020, it is used on the Vulcan launch vehicle beginning with the first launch on January 8, 2024. Up to 6 of the boosters will be mounted on a single Vulcan core, depending on customer needs. It

936-461: The Castor 4 used on 6000-series Delta II. Delta II vehicles could be configured with three, four, or nine GEM 40 boosters. When using three or four boosters, all GEM 40s were ignited on the ground. On nine-booster Delta II, six were ignited on the ground; the remaining three were ignited in flight after burnout of the first six. A variant with a thrust-vectoring nozzle, the GEM 40VN, was developed for

988-629: The Delta IV Medium by 2018. With the exception of the first launch, which carried the Eutelsat W5 commercial communications satellite, all Delta IV launches have been paid for by the US government. In 2015, ULA stated that a Delta IV Heavy is sold for nearly US$ 400 million. The possibility of a higher performance Delta IV was first proposed in a 2006 RAND Corporation study of national security launch requirements out to 2020. A single National Reconnaissance Office (NRO) payload required an increase in

1040-526: The Delta IV Medium+ to accommodate a larger second stage. The motor was retired in 2019 after the final Delta IV Medium launch. Throughout its lifetime, 64 GEM 60 boosters were flown; there were no failures. Data from Northrop Grumman catalog Orbital ATK Orbital ATK Inc. was an American aerospace manufacturer and defense industry company. It was formed in February 9, 2015 from

1092-563: The Delta IV from the commercial market, citing low demand and high costs. In 2005, Boeing stated that it sought to return the Delta IV to commercial service. As of 2009, the USAF funded Delta IV EELV engineering, integration, and infrastructure work through contracts with Boeing Launch Services (BLS). On 8 August 2008, the USAF Space and Missile Systems Center increased the "cost plus award fee" contract with BLS for US$ 1.656 billion to extend

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1144-627: The East coast of the United States used Space Launch Complex 37 (SLC-37) at the Cape Canaveral Air Force Station . On the West coast, polar-orbit and high-inclination launches used Vandenberg Space Force Base 's Space Launch Complex 6 (SLC-6). Launch facilities at both sites are similar. A Horizontal Integration Facility (HIF) is situated some distance from the pad. Delta IV CBCs and second stages to be mated and tested in

1196-506: The Galaxy 10 satellite, depleted their hydraulic fluid used to control the thrust-vectoring nozzle. This was due to guidance issues with the rest of the rocket, which forced the solid rocket motors to make rapid adjustments to compensate, using up the supply of hydraulic fluid before burnout. The nozzles were then stuck in a position that turned the rocket over, triggering the vehicle's self-destruct function 70 seconds after ignition. The GEM 60

1248-635: The HIF before they are moved to the pad. The partial horizontal rocket assembly of the Delta IV is somewhat similar to the Soyuz launch vehicle , which is completely assembled horizontally. The Space Shuttles , the past Saturn launch vehicles , and the Space Launch System are assembled and rolled out to the launch pad entirely vertically. Movement of the Delta IVs among the various facilities at

1300-506: The Heavy, the main CBC's engine throttles down to 58% rated thrust around 50 seconds after liftoff, while the strap-on CBCs remain at 102%. This conserves propellant and allows the main CBC to burn after booster separation. After the strap-on CBCs separate, the main CBC's engine again throttles up to 102% before throttling back down to 58% prior to main engine cutoff. The RS-68 engine is mounted to

1352-515: The Medium+ (5,2) could launch 5,072 kg to GTO. The Delta IV Medium+ (5,4) (Delta 9450) was similar to the Medium+ (5,2), but used four GEM 60s instead of two, enabling it to lift 6,882 kg to GTO. To encapsulate the satellite payload, a variety of different payload fairings were available. A stretched Delta III 4-meter diameter composite payload fairing was used on 4-meter Medium versions, while an enlarged, 5-meter diameter composite fairing

1404-553: The ULA facility in Decatur, Alabama . Final assembly was completed at the launch site by ULA: at the horizontal integration facility for launches from SLC-37B pad at Cape Canaveral and in a similar facility for launches from SLC-6 pad at Vandenberg Space Force Base . The latest evolutionary development of the Delta rocket family , Delta IV was introduced to meet the requirements of

1456-537: The United States Air Force's (USAF) Evolved Expendable Launch Vehicle (EELV, now National Security Space Launch (NSSL)) program. While the Delta IV retains the name of the Delta family of rockets, major changes were incorporated. Perhaps the most significant change was the switch from kerosene to liquid hydrogen fuel, with new tankage and a new engine required. During the Delta IV's development,

1508-415: The addition of two Orbital ATK -built 1.5-m (60-in) diameter solid rocket booster Graphite-Epoxy Motors (GEM 60s) strap-on boosters to increase payload capacity to 6,150 kg to GTO. The Delta IV Medium+ (5,2) (Delta 9250) was similar to the Medium+ (4,2), but had a 5-m–diameter DCSS and payload fairing for larger payloads. Because of the extra weight of the larger payload fairing and second stage,

1560-454: The anomaly suggest the GEM 63XL's engine nozzle was either damaged or suffered a structural failure 35 seconds after ignition. Vulcan Centaur Cert-2 continued into orbit successfully after burnout and separation of its two GEM 63XL boosters at approximately 2 minutes 10 seconds into flight. As of 4 October 2024, ULA is still investigating the cause of the anomaly. The GEM 40 was a 40.4-inch-diameter (1,030 mm) solid rocket motor developed for

1612-596: The back of the CBC is a cable tunnel to hold electrical and signal lines, and a feedline to carry the liquid oxygen to the RS-68 from the tank. The CBC is of a constant, 5 m (16 ft) diameter. The upper stage of the Delta IV was the Delta Cryogenic Second Stage (DCSS). The DCSS was based on the Delta III upper stage but has increased propellant capacity. Two versions have been produced:

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1664-654: The canister and commercial markets. The Defense Systems Group became part of Northrop Grumman Defense Systems on January 1, 2020. Orbital ATK's Space Systems Group provides satellites for commercial , scientific, and security purposes. This group also produces the Cygnus spacecraft, which delivers cargo to the International Space Station . The group was based at the company's headquarters on Warp Drive in Dulles, Virginia . Delta IV Delta IV

1716-463: The case of Delta IV, the vehicle was completed on the launch pad inside a building. This Mobile Service Tower (MST) provides service access to the rocket and protection from the weather and is rolled away from the rocket on launch day. A crane at the top of the MST lifts the encapsulated payload to the vehicle and also attached the GEM 60 solid motors for Delta IV Medium launches. The MST is rolled away from

1768-402: The conclusion of the Delta rocket family. Each Delta IV consists of at least one Common Booster Core (CBC). Each CBC is powered by one Aerojet Rocketdyne RS-68 engine, which burns liquid hydrogen and liquid oxygen . On flights of the Medium, the RS-68 ran at 102% rated thrust for the first few minutes of flight, and then throttled down to 58% rated thrust before main engine cutoff. On

1820-441: The first stage and DCSS. A tapering interstage that narrowed down from 5 m to 4 m diameter was used to mate the 4 m DCSS to the CBC, while a cylindrical interstage is used to mate the 5 m DCSS. Both interstages were built from composites and enclosed the liquid oxygen tank, with the larger liquid hydrogen tank making up part of the vehicle's outer mold line. Delta IV launched from either of two rocket launch complexes . Launches on

1872-642: The lift capability of the Delta IV Heavy. Lift capacity was increased by developing the higher-performance RS-68A engine, which first flew on 29 June 2012. ULA phased out the baseline RS-68 engine with the launch of Delta flight 371 on 25 March 2015. All following launches used the RS-68A, and the engine's higher thrust allowed the use of a single standardized CBC design for all Delta IV Medium and M+ versions. This upgrade reduced cost and increased flexibility, since any standardized CBC could be configured for zero, two, or four solid-propellant rocket boosters. However,

1924-418: The lower thrust structure of the CBC by a four-legged ( quadrapod ) thrust frame and enclosed in a protective composite conical thermal shield. Above the thrust structure is an aluminum isogrid (a grid pattern machined out of the inside of the tank to reduce weight) liquid hydrogen tank, followed by a composite cylinder called the centerbody, an aluminum isogrid liquid oxygen tank, and a forward skirt. Along

1976-500: The merger of Orbital Sciences Corporation and parts of Alliant Techsystems (ATK). Orbital ATK designed, built, and delivered rocket engines , military vehicles , firearms , autocannons , missiles , ammunition , precision-guided munitions , satellites , missile approach warning systems , launch vehicles and spacecraft . The company was acquired by Northrop Grumman on June 6, 2018. The former Orbital ATK operations were renamed Northrop Grumman Innovation Systems and operated as

2028-433: The new CBC led to a slight performance loss for most medium configurations. The Delta IV Heavy required non-standard CBCs for the core and boosters. Payload capacities after RS-68A upgrade 407 km x 51.6° 1800 m/s residual Payload capacities with original RS-68 Version Fairing CBCs SRBs Payload to LEO 407 km x 51.6° Payload to GTO 1800 m/s residual Launches *Masses include

2080-423: The pad was facilitated by rubber-tired Elevating Platform Transporters (EPTs) and various transport jigs. Diesel engine EPTs are used for moving the vehicles from the HIF to the pad, while electric EPTs are used in the HIF, where precision of movement is important. The basic launchpad structure includes a flame trench to direct the engine plume away from the rocket, lightning protection, and propellant storage. In

2132-538: The period of performance through the 30 September 2008 ( FY09 ). In addition, a US$ 557.1 million option was added to cover FY10. In February 2010, naturalized citizen Dongfan Chung, an engineer working with Boeing, was the first person convicted under the Economic Espionage Act of 1996 . Chung passed on classified information on designs including the Delta IV rocket to China and was sentenced to 15 years. In March 2015, ULA announced plans to phase out

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2184-702: The proposed Orbital Space Plane , which eventually became the Crew Exploration Vehicle and then the Orion . Orion was intended to fly on the Ares I launch vehicle, then the Space Launch System after Ares I was cancelled. In 2009, The Aerospace Corporation reported on NASA results of a study to determine the feasibility of modifying Delta IV to be crew-rated for use in NASA human spaceflight missions. According to Aviation Week & Space Technology

2236-449: The rocket several hours before launch. At Vandenberg, the launch pad also has a Mobile Assembly Shelter (MAS), which completely encloses the vehicle; at CCAFS, the vehicle is partly exposed near its bottom. Beside the vehicle is a Fixed Umbilical Tower (FUT), which has two (VSFB) or three (CCAFS) swing arms. These arms carry telemetry signals, electrical power, hydraulic fluid, environmental control air flow, and other support functions to

2288-537: The same day. On September 18, 2017, Northrop Grumman announced plans to purchase Orbital ATK for US$ 7.8 billion in cash plus assumption of US$ 1.4 billion in debt. Orbital ATK shareholders approved the buyout on November 29, 2017. The Federal Trade Commission (FTC) approved the acquisition with conditions on June 5, 2018, and on June 6, 2018, Orbital ATK was renamed Northrop Grumman Innovation Systems. With Northrop Grumman's reorganization of its divisions effective January 1, 2020, Northrop Grumman Innovation Systems

2340-421: The study, "found that a Delta IV heavy [...] could meet NASA's requirements for getting humans to low Earth orbit". A proposed upgrade to the Delta IV family was the addition of extra solid motors. The Medium+ (4,4) would have used existing mount points to pair the four GEM 60s of the M+ (5,4) with the upper stage and fairing of the (4,2). An M+ (4,4) would have had a GTO payload of 7,500 kg (16,500 lb),

2392-538: The vehicle. After the discontinuation of the Delta III, GEM 46 motors (without TVC) were used on the Delta II to create the Delta II Heavy, which could only be launched from a modified pad at Cape Canaveral Air Force Station , SLC-17B . Both Delta III and Delta II Heavy used nine GEM 46s, with six ignited on the ground and three air-lit. On 27 August 1998, the GEM 46 boosters on the first Delta III, carrying

2444-510: Was a 60-inch-diameter (1,500 mm) solid motor used on the Delta IV family of launch vehicles, used with and without thrust vector control. Developed for the EELV program, its first flight was on 20 November 2002, boosting the first launch of the Delta IV. Delta IV Medium+ launchers were built with either two or four GEM 60. The added performance from the solid rocket motors allowed variants of

2496-509: Was a group of five expendable launch systems in the Delta rocket family . It flew 45 missions from 2002 to 2024. Originally designed by Boeing 's Defense, Space and Security division for the Evolved Expendable Launch Vehicle (EELV) program, the Delta IV became a United Launch Alliance (ULA) product in 2006. The Delta IV was primarily a launch vehicle for United States Air Force (USAF) military payloads, but

2548-406: Was also used to launch a number of United States government non-military payloads and a single commercial satellite. The Delta IV had two main versions which allowed the family to cover a range of payload sizes and masses: the Medium (which had four configurations) and Heavy . The final flight of Medium occurred in 2019. The final flight of Heavy was in April 2024. Delta IV vehicles were built in

2600-583: Was split, with most of the sector merging with other Northrop Grumman businesses into a new Space Systems sector. Based in Chandler, Arizona , the Flight Systems Group includes the Pegasus , Minotaur , and Antares launch vehicles as well as solid-propulsion and aerostructures programs. The company also operates a Lockheed L-1011 TriStar wide body jetliner, which is named Stargazer and

2652-521: Was standard on the Delta IV Heavy, with an aluminum isogrid fairing also available. The aluminum trisector (three-part) fairing was built by Boeing and derived from a Titan IV fairing. The trisector fairing was first used on the DSP-23 flight. The Delta IV with the extended fairing is over 62 m (203 ft) tall. The last launch took place on 9 April 2024, carrying the NROL-70 satellite, marking

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2704-428: Was used on 5-meter Medium versions. The Medium (4,2) version last flew on 22 August 2019, marking the retirement of the Delta IV Medium variants. The Delta IV Heavy (Delta 9250H) combines a 5 m (16 ft) diameter DCSS and payload fairing with two additional CBCs. These are strap-on boosters which are separated earlier in the flight than the center CBC. As of 2007, a longer 5 meter diameter composite fairing

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