Space Launch Report:  Delta IV Data Sheet
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Vehicle Configurations

Vehicle Components

Delta 4 Launch Record

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.

Third Delta IV, a Medium VariantThe 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.

3rd Delta IV at SLC 37B (Boeing)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.

d317u.jpg (14869 bytes)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 those seconds. 

d360g.jpg (18254 bytes)Heavy Upgrade Program

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.

d369as.jpg (12077 bytes)Orion EFT-1

Delta 4 Heavy (Delta 369) with EFT-1 Prelaunch

NASA's Orion Exploration Flight Test 1 began with a 12:05 UTC liftoff from Cape Canaveral Air Force Station Space Launch Complex 37B on December 5, 2014.  The eighth Delta 4 Heavy launch vehicle boosted EFT-1, with the first unmanned Orion Command Module, into an initial 186 x 894 km x 28.4 deg orbit after a 17 minute 39 second ascent. Delta 4's twin outer booster cores burned out and jettisonned 3 minutes 58 seconds after liftoff.  The core first stage shut down at the 5 minute 30 second mark.  The Delta Heavy Cryogenic Second Stage then performed an 11 minute 30 second first burn to reach low earth orbit.

Orion remained attached to Delta 4's cryogenic second stage in orbit, awaiting a second burn about 1 hour 55 minutes into the flight at the end of the first orbit.  This second burn was expected to loft EFT-1 to a nearly 6,000 km apogee on a suborbital trajectory, creating high speed reentry conditions of up to 9,000 meters per second to test Orion's Avcoat ablative heat shield.  Orion uses the largest, heaviest ablative heat shield ever flown in space.

d369bs.jpg (19055 bytes)EFT-1 Liftoff

Important separation events were successfully performed during the ascent, including separation of three 450 kg Service Module Fairings at the 6 minute 20 second mark, about 30 seconds into the second stage burn, and of the roughly 7.5 tonne Launch Abort System (LAS) about 5 seconds later.  The LAS had inert Abort and Attitude Control solid motor simulators, but used a live Jettison Motor to pull itself and its large fairing away from Orion.

Delta 4 Heavy weighed 740 tonnes at liftoff, including Orion, its dummy Service Module and Stage Adapter, the mostly-inert Launch Abort System with its fairing, and jettisonable Service Module panels. In orbit, the Orion Command Module and dummy Service Modules together likely weighed roughly 11.5 to 12 tonnes. The CM alone weighed about 9 to 9.5 tonnes in orbit and 8.6 tonnes at splashdown. The LAS likely weighed about 7.7-7.8 tonnes.

eft1diag.jpg (11831 bytes)Diagram Showing EFT-1 LAS and SM Fairing Separation

After coasting in its initial low earth orbit, the second stage restarted its Pratt & Whitney Rocketdyne RL10B-2 engine at the 1 hour 55 minute mark, performing a 4 minute 43 second burn to boost Orion into its final elliptical orbit, which had a -20 km perigee, a 5,809 km apogee, and 28.77 deg inclination.  The second stage was expected to perform a third, de-orbit burn after the CM separated. 

The CM and SM remained attached to the Delta 4 cryogenic second stage until the CM separated for reentry about 3 hours 23 minutes after launch, after the vehicle began falling back to Earth from apogee.  At that point, the CM began using its own reaction control system, consisting of 12 monopropellant thrusters, to control its attitude.  The CM performed a brief "Raise Burn" to test its capabilities about 3 hours 57 minutes after liftoff.

eft1go1.jpg (23315 bytes)d369ds.jpg (6622 bytes)Left:  Orion EFT-1 Launch Abort System Fairing Installation at Kennedy Space Center

Right:  Orion Approaches Splashdown

Orion's entry interface occurred at about the 4 hours 13 minute mark.  The capsule was travelling at a velocity of nearly 9,000 meters per second when it hit the atmosphere.   This represented about 84% of the reentry velocity expected by a CM returning from future planned SLS-launched deep space missions.  During reentry, Orion experienced peak heating of about 4,000 F and maximum g-forces of 8.0 to 8.3. 

The Orion CM reentered and splash down under three main parachutes in the Pacific Ocean about 444 km west of Baja, California about 4.5 hours after liftoff.  Splashdown occurred 4 hours 24 minutes after liftoff.  The A U.S. Navy team, based on the U.S.S. Anchorage (LPD-23, a San Antonio-class amphibious transport dock), recovered the spacecraft.

d369cs.jpg (16964 bytes)Orion Recovery Operations

Lockheed Martin assembled Orion at Kennedy Space Center's Operations & Checkout Building during a two year buildup.  The company bought the Delta 4 Heavy launch from United Launch Alliance in 2010.  NASA's Marshall Space Flight Center built the Stage Adapter.  ATK built the Launch Abort System motors.

It was the first civilian payload carried by Delta 4 Heavy.  After its initial demonstration test flight in 2004, the world's heaviest lifter boosted six Defense Department payloads, including five top secret missions for the National Reconnaisance Office.  EFT-1 may have been the heaviest payload at liftoff of a Delta 4 Heavy, but it was likely not the heaviest payload placed into orbit.  EFT-1 shed nearly half of its mass en route to orbit.

Vehicle Configurations

(metric tons)
407 km x
(1) 51.6 deg
(2) 90 deg
(metric tons)
200 km x
(1) 28.7 deg
(2) 90 deg
1500 m/s
to GEO*
1800 m/s
to GEO
Configuration LIftoff
(metric tons)
No Payload
Delta IV-M 8.80 t (1)
7.75 t (2)
  3.70 t 4.54 t CBC + 4mS2
+ 4mPF
62.5 m 257 t
Delta IV-M (RS-68A) 8.51 t (1) 9.19 t (1)
7.69 t (2)
  4.21 t CBC + 4mS2
+ 4mPF
62.5 m 257 t
Delta IV-M+(4,2) 11.92 t (1)
10.44 t (2)
  5.15 t 6.27 t CBC + 2GEM60
+ 4mS2 + 4mPF
62.5 m 323 t
Delta IV-M+(4,2) (RS-68A) 12.00 t (1) 12.90 t (1)
10.53 t (2)
  6.16 t CBC + 2GEM60
+ 4mS2 + 4mPF
62.5 m 323 t
Delta IV-M+(5,2) 10.58 t (1)
9.09 t (2)
  4.25 t 5.43 t CBC + 2GEM60
+ 5mS2 + 5mPF
66.4 m 332 t
Delta IV-M+(5,2) (RS-68A) 10.22 t (1) 11.06 t (1)
9.61 t (2)
  5.08 t CBC + 2GEM60
+ 5mS2 + 5mPF
66.4 m 332 t
Delta IV-M+(5,4) 13.45 t (1)
11.72 t (2)
  5.85 t 7.43 t CBC + 4GEM60
+ 5mS2 + 5mPF
66.4 m 399 t
Delta IV-M+(5,4) (RS-68A) 12.82 t (1) 13.73 t (1)
11.6 t (2)
  6.89 t CBC + 4GEM60
+ 5mS2 + 5mPF
66.4 m 399 t
Delta IV-H 22.98 t (1)
21.56 t (2)
  11.40 t 13.40 t 3CBC + 5mS2
+ 5mPF
71.65 m 732 t
Delta IV-HU (RS-68A) 25.98 t (1) 28.37 t (1)
23.56 t (2)
  13.80 t 3CBC + 5mS2
+ 5mPF
71.65 m 732 t

* GEO: Geosynchronous Earth Orbit
* Payload masses include Payload Attach Fitting (PAF)
  Original RS-68 Versions (Shaded) Being Phased Out Over Time Beginning 2015.

Vehicle Components

Core (CBC)
First Stage
Core (CBC)
First Stage
Delta IV 4 m
Second Stage
Delta IV 5m
Second Stage
4m PLF 5m PLF
Diameter (m) 1.52 m 5.1 m 5.1 m 4.0 m 5.1 m 4 m 5.1 m
Length (m) 15.2 m 36.6 m 36.6 m 12.2 m 13.7 m 11.75 m 19.72 m
Usable Propellant Mass (tons) 29.70 t ~204 t ~204 t 20.41 t*** 27.20 t***    
Burnout Mass (tons) 3.79 t ~27 t/28 t** ~27 t/28 t** ~2.78 t ~3.35 t    
Total Mass (tons) 33.49 t ~231/232 t** ~231/232 t** ~23.19 t ~30.55 t ~2.8 t ~3.55 t
Engine GEM-60 RS-68 RS-68A RL10B-2
Engine Mfgr Alliant Rocketdyne Rocketdyne Pratt & Whitney Pratt & Whitney    
Fuel HTPB LH2 LH2 LH2 LH2    
Oxidizer   LOX LOX LOX LOX    
(SL tons)
113.38 t (max) 300.41 t 318.43 t        
(Vac tons)
89.60 t (avg) 343 t 361.52 t 11.202 t 11.202 t    
ISP (SL sec) 273.9 s (avg) 357 s ~360 s        
ISP (Vac sec)   407.55 s 414 s 460.4 s 460.4 s    
Burn Time (sec) 90.8 s 242-333 s 242-333 s 840 s 1118 s    
No. Engines 0-4 1 1 1 1    

** 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.

*** Propellant loadings for GTO missions shown. Propellant loadings would be less for LEO missions with heavy payloads.  Stage 2 masses do not include payload attachment fittings, which weigh 0.24 to 0.4 tonnes. 

Delta 4 Launch Record

                         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             ~6000? CC37B 35587x35587x0 ?    GEO?(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
07/28/14 Delta 4M+4,2 D368  2xGSSAP/ANGELS             CC37B                    GEO?
12/05/14 Delta 4H     D369  EFT-1 (Orion)      ~12000  CC37B -20x5809x28.77     EEO (5)
(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. 
(5)First unmanned test of Orion spacecraft CM. Liftoff mass 21 tonnes including 
LAS, SM Fairings, and Stage Adapter.  CM ~9.2 tonnes. DCSS first burn to LEO, second 
burn during 2nd orbit to 5809 km apogee for high speed reentry and splashdown of 
Baja, California.  DCSS performed third, deorbit burn.
*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:


Delta IV Payload Planners Guide, Boeing, October 2000
Delta IV Payload Planners Guide Update, Boeing, April 2002
Delta IV Payload Planners Guide Update, Boeing, November 2002
Delta IV Heavy Demosatration Flight Media Kit, Boeing, June 2005
Delta IV Payload Planners Guide, ULA, September 2007
ATK Space Propulsion Products Catalog, 2008
PWR Press Release, RS-68A Acceptance Testing, March 2011.
PWR Press Release, "Three Pratt & Whitney Rocketdyne RS-68A Engines Power Delta IV Heavy Upgrade Vehicle on Inaugural Flight", June 29, 2012.
Atlas V and Delta IV Technical Summary, ULA, June 2013.

 Last Update:  December 10, 2014