35-626: Delta IV 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
70-470: 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
105-671: 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
140-472: 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
175-423: 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
210-518: 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
245-531: 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
280-666: 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 the Space Shuttle main engine (SSME) in the 1970s. The L3 Technologies Redundant Inertial Flight Control Assembly (RIFCA) guidance system originally used on
315-510: 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, a small variant was considered. This would have featured the Delta II second stage, an optional Thiokol Star 48B third stage, and
350-425: 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 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
385-626: 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
SECTION 10
#1732780661121420-633: 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
455-505: 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
490-513: 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
525-717: 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 the United States Air Force's (USAF) Evolved Expendable Launch Vehicle (EELV, now National Security Space Launch (NSSL)) program. While
560-469: 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 the lift capability of the Delta IV Heavy. Lift capacity was increased by developing
595-607: 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 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,
630-414: 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,
665-595: 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:
700-512: 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
735-401: 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
SECTION 20
#1732780661121770-439: 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
805-553: 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,
840-418: 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
875-431: 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
910-422: 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
945-701: 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
980-448: 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
1015-420: 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),
1050-597: The vehicle through umbilical lines. The swing arms retract at T-0 seconds once the vehicle is committed to launch. Expendable launch system Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.226 via cp1108 cp1108, Varnish XID 222312012 Upstream caches: cp1108 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 07:57:41 GMT Eutelsat 33B Too Many Requests If you report this error to
1085-405: 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 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,
Delta IV - Misplaced Pages Continue
1120-406: 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
1155-518: 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
1190-561: 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 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
1225-425: 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
#120879