|Space Launch Report: Delta IV Data Sheet|
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Boeing developed Delta IV to compete for U.S. Air Force Evolved Expendable Launch Vehicle (EELV) launch contracts. Although it carries the "Delta" name, the big new rocket has little in common with with long running Douglas/NASA Thor-Delta series.
The United Launch Alliance consortium, a new company spun off by Boeing and Lockheed Martin, took over the Delta IV and Atlas V EELV programs in December 2006.
Several Delta IV models are available to loft 3 to 11 ton payloads into geosynchronous transfer orbit (GTO) or 8.4 to 22.5 ton payloads into low earth orbit (LEO). Planned versions include the Medium, Medium Plus (4,2), Medium Plus (5,2), Medium Plus (5,4), and the Heavy.
Delta IV is built around the 5.1 meter diameter Common Booster Core (CBC) first stage powered by a single 300 metric ton thrust Rocketdyne RS-68. The liquid hydrogen (LH2) and liquid oxygen (LOX) engine is the world's most powerful cryogenic engine and is the first new big liquid propellant rocket engine developed in the U.S. in more than 20 years.
RS-68 was designed to meet cost criteria. It operates at comparatively moderate chamber pressures using a basic gas generator cycle. The gas generator drives a turbopump. Turbine exhaust gases are vectored to provide first stage roll control. Rocketdyne borrowed some technology from the Space Shuttle Main Engine and from the Saturn J-2 engine, but much is new. The engine's part count was reduced through use of an ablative exhaust nozzle, for example. RS-68 engine testing began at Edwards Air Force Base, California in August 1998.
Delta IV is assembled at a purpose-built rocket plant in Decatur, Alabama, several miles west of Huntsville. When finished, the rockets are floated on a special self-propelled shipping vessel down the Tennessee River and Tombigbee Waterway (canal) to the Gulf of Mexico. From there they travel either to Cape Canaveral via the Intercostal Waterway or to Vandenberg Air Force Base via the Panama Canal.
The CBC is composed of four main structural subassemblies. These include the engine section, the aft LH2 tank, the intertank section, and the forward LOX tank, all 5.2 meters in diameter. Five aluminum isogrid skin panels are welded together to make the cylindrical tank sections. Interior stingers are added for reinforcement. An external feed pipe carries LOX around the LH2 tank. An external wiring tunnel runs the length of the booster.
Two Delta IV LOX/LH2 second stages are available. The first is a stretched Delta III second stage with a 4 meter diameter forward LH2 tank. The second has a 5.1 meter diameter LH2 tank. Both use a 3 meter LOX tank suspended beneath the LH2 tank by an intertank truss. Mitsubishi Heavy Industries of Japan builds the LH2 tanks.
Both second stages are powered by a single Pratt and Whitney RL10B-2 engine. The engine has a French-built extendable exit cone, is restartable, and is capable of producing 11.23 tons of thrust. At one point, Mitsubishi and Boeing were jointly developing a new, more powerful engine, based on H-2A technology, that might eventually replace RL10, but this effort was apparently shelved after Boeing sold Rocketdyne to Pratt & Whitney in 2005.
The entire vehicle is controlled by an Allied Signal Redundant Inertial Flight Control Assembly (RIFCA) flight control system that is located on shelf below the second stage LOX tank.
Delta IV M (Medium) uses one CBC, a 4 meter diameter second
stage, a stretched Delta 3 composite payload fairing, and a 5.1 meter to 4 meter tapered
interstage. Two Alliant GEM 60-inch diameter solid rocket motors added to the base of the
CBC turns the rocket into the Delta IV M+(4,2). A 5.1 meter diameter second stage,
interstage, and payload fairing with two or four SRMs makes a Delta IV M+(5,2) and Delta
IV M+(5,4), respectively. Delta IV H (Heavy) uses two CBC strap-on liquid rocket boosters
and a 5 meter upper stage.
Delta IV is integrated horizontally in a Horizontal Integration Facility (HIF) and erected at the launch pad less than two weeks before launch. SRMs, if any, are then added to the vehicle. The encapsulated payload is mated to the vehicle at the pad a few days before launch. At Cape Canaveral, the long-dormant former Saturn 1/1B Pad 37B was rebuilt for Delta IV. The site includes a rail-mobile mobile service tower that is more 100 meters tall. At California's Vandenberg Air Force Base, Delta IV will be launched from Space Launch Complex (SLC) 6, a pad developed but never used for space shuttle launches. SLC 6 facilities include a mobile service tower and a mobile assembly shelter, massive enclosures that enclose the launcher from two directions like a clamshell.
The first Delta IV, an M+(4,2) model, successfully orbited
Eutelsat W5 from SLC 37B on November 20, 2002. It was followed by two successful Delta IV
M EELV flights during 2003. The first Delta IV Heavy lifted off from Cape Canaveral in
2004. The test flight achieved some objectives, but was marred when the first stage shut
down several seconds too soon. The cause of the problem was a faulty first stage LOX
depletion sensor signal that resulted when LOX cavitation occured in the LOX feedline.
The LOX feedline/sensor design was modified and the problem did not recur on
subsequent Delta IV Heavy missions.
The first Vandenberg AFB Delta 4 launch took place on June 28, 2006 when a Delta IVM+(4,2) placed NRO L-22, a National Recconnaisance Office payload, into an elliptical 12 hour Molniya orbit.
A complete list of Delta 4 and Atlas 5 launches is provided on the EELV Launch Log page.
On Delta IV M missions, the CBC burns for more than four minutes, separating when the vehicle is more than 100 kilometers above the earth. On M+ flights, two to four GEM-60 SRMs burn during the first 90.8 seconds of flight.
On Delta IV Heavy flights, all three CBCs ignite on the
pad. The core CBC engine throttles down to 57% about 50 seconds after liftoff. The twin
strap-on booster CBC units burn at full thrust until shortly before they complete their
burns. The strap-on units are jettisonned about 242 seconds after liftoff. The
core flies on for another 90-plus seconds, returning to full-throttle for more than 65 of
Delta 360 Launch
An NRO triggered program to upgrade the RS-68 engine to an "RS-68A" variant, called "Heavy Upgrade Program", or "HUG", resulted in the first hot fire test of a prototype engine at Stennis Space Center in September 2008. Two certification engines completed their testing programs during February and November of 2010, respectively. The first three production engines, Nos. 30003-30005, were delivered from Stennis to Decatur during April 2011 after completing their hot fire acceptance tests.
The three engines performed the first RS-68A launch on June 29, 2012, when Delta 360, a Delta 4-Heavy Upgrade, orbited the NROL-15 payload from Cape Canaveral. The engines produced a combined liftoff thrust of nearly 955.28 tonnes (2.1 million pounds), a roughly 6 percent increase from the previous RS-68 engine thrust. A post-launch press release noted that Pratt & Whitney Rocketdyne (PWR) had developed RS-68A specifically to be able to lift the NROL-15 payload. The new engine produced 318.43 tonnes of liftoff thrust and 361.52 tonnes of thrust in vacuum. RS-68A vacuum specific impulse was targeted for 414 seconds, about 6.5 seconds more than the RS-68 value.
The improved performance was expected to increase Delta 4 Heavy's performance by 8 to 13 percent, depending on orbit. RS-68A will be phased into the entire Delta 4 fleet starting in 2015. The new engine will allow all of the Medium configurations to use a standard Medium+(5,4) core, rather than cores tailor made for each type of strap on solid motor set up. As a result, most the Medium variants would see slight performance losses compared to their original versions, but the move would achieve program cost savings.
Another change will involve the second stage engine.
Excess RL10B-2 Delta 4 engines are being converted to RL10C-1 variants for use on Atlas
5. As part of this effort, some changes will be made to RL10B-2 engines to improve
commonality between Delta 4 and Atlas 5. The resulting RL10C-2 engines for Delta 4
will look much like RL10B-2 but will have have improved ignition systems, an updated
propellant valve design, and other changes.
* GEO: Geosynchronous Earth Orbit
** Dry mass for Delta IV Medium version
believed to include 5-4 meter interstage. Dry mass for Delta IV Medium 5-5 meter version
interstage and for Delta IV Heavy versions with nose cones or 5 meter adapter are believed
to weigh about one metric ton more than Medium CBC.
====================================================================================== as of May 17, 2014 ====================================================================================== Date Vehicle ID Payload Mass Site* Orbit Orbit kg (kmxkmxdeg) Type** ---------------------------------------------------------------------------------------- 11/20/02 Delta 4M+4,2 D293 Eutelsat W5 3170 CC37B 539x35921x13.49 GTO 03/11/03 Delta 4M D296 DSCS-3-A3 2733 CC37B 235x35587x25.5 GTO 08/29/03 Delta 4M D301 DSCS B6 2733 CC37B 235x35551x25,5 GTO 12/21/04 Delta 4H D310 Demosat/2microsats 6000 CC37B 19029x36408x13.48 [EEO](1) 05/24/06 Delta 4M+4,2 D315 GOES-N 3199 CC37B 6656x35173x12.1 GTO+ 06/28/06 Delta 4M+4,2 D317 NROL-22 4000? VA6 1111x37564x62.4 EEO/M 11/04/06 Delta 4M D320 DMSP-17 1225 VA6 846x850x98.77 LEO/S 11/11/07 Delta 4H D329 DSP-23 2386 CC37B 35902x35902x4.0 GEO 01/18/09 Delta 4H D337 NROL-26 6000? CC37B GEO? 06/27/09 Delta 4M+4,2 D342 GOES-O 3211 CC37B 6623x35177x12 GTO+ 12/06/09 Delta 4M+5,4 D346 WGS F3 5987 CC37B 441x66874x24 GTO+ 03/04/10 Delta 4M+4,2 D348 GOES-P 3238 CC37B 6623x35177x12 GTO+ 05/28/10 Delta 4M+4,2 D349 GPS 2F-1 1630 CC37B 20459x20459x55 MEO 11/21/10 Delta 4H D351 NROL-32 CC37B GEO? 01/20/11 Delta 4H D352 NROL-49 VA6 250x1020x97.9 LEO/S 03/11/11 Delta 4M+4,2 D353 NROL-27 CC37B GEO? 07/16/11 Delta 4M+4,2 D355 GPS 2F-2 1630 CC41 20430x20465x55 MEO 01/20/12 Delta 4M+5,4 D358 WGS 4 5988 CC37B 439x66872x24 GTO+ 04/03/12 Delta 4M+5,2 D359 NROL-25 ~6000? VA6 1100x1100x123 LEO/R 06/29/12 Delta 4H D360 NROL-15 CC37B GTO?(3) 10/04/12 Delta 4M+4,2 D361 GPS 2F-3 1630 CC37B 20459x20459x55 MEO(4) 05/25/13 Delta 4M+5,4 D362 WGS 5 5988 CC37B 441x66854x24 GTO+ 08/08/13 Delta 4M+5,4 D363 WGS 6 5987 CC37B 439x66894x24 GTO+ 08/28/13 Delta 4H D364 NROL 65 ~17000 VA6 254x999x97.9 LEO/S 02/21/14 Delta 4M+4,2 D365 GPS 2F-5 1630 CC37B 20459x20459x55 MEO 05/17/14 Delta 4M+4,2 D366 GPS 2F-6 1630 CC37B 20459x20459x55 MEO Delta 4 Launch Forecast (Notice: Subject to Frequent and Substantial Modification) --/--/14 Delta 4M+4,2 AFSPC 4 CC37B ??? --/--/14 Delta 4H Orion EFT-1 CC37B EEO ---------------------------------------------------------------------------------------- (1)Failure during inaugural test flight with dummy 6 metric ton Demosat payload and two LEO microsats. CBC strap-on boosters shut down 8 sec early. The core CBC shut down 9 sec early. Initial second stage burn ran long to compensate, using more propellant than planned to reach LEO. Second burn achieved correct geosynchronous transfer orbit. Third burn ended early due to propellant depletion. Microsats failed to orbit - deployed into suborbital trajectory. Demosat orbit 19,029 x 36,408 km at 13.48 degree inclination versus planned 36,342 km circular at 10 degrees (perigee short by 17,313 km). (3)First use of upgraded RS-68A engines, producing a combined 2.106 million pounds of liftoff thrust. (4)Successful mission/orbit, but RL10B-2 stg 2 engine produced low thrust during its three burns, causing burns to be extended by 30 seconds or more (perhaps 6-8% burn length increase/thrust decrease.) Propellant leak in thrust chamber. *Site Code: CC = Cape Canaveral, FL, USA CC37B = Space Launch Complex 37B: Delta 4 CC41 = Space Launch Complex 41: Atlas 5 VA = Vandenberg AFB, CA, USA VA3E = Space Launch Complex 3E: Atlas 5 VA6 = Space Launch Complex 6: Delta 4 **Orbit Code: References
Delta IV Payload Planners Guide, Boeing, October 2000
Last Update: May 17, 2014