Delta IV Heavy

Delta IV Heavy
Delta IV Heavy launches from Vandenberg Air Force Base
Function Orbital heavy-lift launch vehicle
Manufacturer United Launch Alliance
Country of origin United States
Cost per launch US$350 million
NRO: US$440 million
Size
Height 72 m (236 ft)
Diameter 5 m (16 ft)
Width 15 m (49 ft)
Mass 733,000 kg (1,616,000 lb)
Stages 2+
Capacity
Payload to LEO
Mass 28,790 kg (63,470 lb)
Payload to GTO
Mass 14,220 kg (31,350 lb)
Associated rockets
Family Delta
Comparable
Launch history
Status Production ended
Launch sites
Total launches 15
Success(es) 14
Partial failure(s) 1
First flight 21 December 2004 (USA-181)
Last flight 22 June 2023 (NROL-68)
Type of passengers/cargo
Boosters (CBC)
No. boosters 2
Height 40.8 m (134 ft)
Diameter 5.1 m (17 ft)
Empty mass 26,000 kg (57,000 lb)
Gross mass 226,400 kg (499,100 lb)
Propellant mass 200,400 kg (441,800 lb)
Powered by 1 RS-68A
Maximum thrust 3,140 kN (710,000 lbf)
Total thrust 6,280 kN (1,410,000 lbf)
Specific impulse Sea level: 360 s (3.5 km/s)
Vacuum: 412 s (4.04 km/s)
Burn time 242 seconds
Propellant LH2 / LOX
First stage (CBC)
Height 40.8 m (134 ft)
Diameter 5.1 m (17 ft)
Gross mass 226,400 kg (499,100 lb)
Propellant mass 200,400 kg (441,800 lb)
Powered by 1 RS-68A
Maximum thrust 3,140 kN (710,000 lbf)
Specific impulse Sea level: 360 s (3.5 km/s)
Vacuum: 412 s (4.04 km/s)
Burn time 328 seconds
Propellant LH2 / LOX
Second stage (DCSS)
Height 13.7 m (45 ft)
Diameter 5.1 m (17 ft)
Gross mass 30,700 kg (67,700 lb)
Propellant mass 27,220 kg (60,010 lb)
Powered by 1 RL10-B-2
Maximum thrust 110 kN (25,000 lbf)
Specific impulse 462 s (4.53 km/s)
Burn time 1125 seconds
Propellant LH2 / LOX
[edit on Wikidata]

The Delta IV Heavy (Delta 9250H) is an expendable heavy-lift launch vehicle, the largest type of the Delta IV family. It is the world's third highest-capacity launch vehicle in operation, behind NASA's Space Launch System and SpaceX's Falcon Heavy and closely followed by CASC's Long March 5. It is manufactured by United Launch Alliance (ULA) and was first launched in 2004. ULA will retire the Delta IV Heavy in 2024. As of June 2023, one flight remains.

The Delta IV Heavy consists of a central Common Booster Core (CBC), with two additional CBCs as liquid rocket boosters instead of the GEM-60 solid rocket motors used by the Delta IV Medium+ versions. At lift off, all three cores operate at full thrust, and 44 seconds later the center core throttles down to 55% to conserve fuel until booster separation. The two side boosters burn out at 242 seconds after launch and are separated as the core booster throttles back up to full thrust. The core burns out 86 seconds later, and the second stage completes the ascent to orbit.

The launch vehicle uses three RS-68 engines, one in the central core and one in each booster. On the last seconds of countdown, the hydrogen fuel flows through the engines and upwards along the booster body, and after the ignition that hydrogen inflames, making the characteristic fireball and charred look of the booster.

History

Delta IV Heavy for Exploration Flight Test-1

The Delta IV line of rockets was developed by Boeing. The program was later transferred to United Launch Alliance. The Delta IV Heavy is the most powerful member of the line, which also includes the smaller Delta IV Medium. The Delta IV Heavy can lift 28,370 kg (62,550 lb) to low Earth orbit and 13,810 kg (30,450 lb) to geostationary transfer orbit (GTO). It is an all liquid-fueled launch vehicle, consisting of an upper stage, one main booster and two strap-on boosters.

The first launch of the Delta IV Heavy on 21 December 2004 carried a boilerplate payload and was a partial failure. Cavitation in the liquid-oxygen propellant lines caused shutdown of both boosters eight seconds early, and the core engine nine seconds early; this resulted in a lower staging velocity for which the second stage was unable to compensate. The payload was left in a lower than intended orbit. Its first operational payload was the DSP-23 satellite, successfully launched in 2007; it was then used to launch a further five visual and electronic reconnaissance satellites for the National Reconnaissance Office (NRO) through 2013.

In December 2014, the Delta IV Heavy was used to launch an un-crewed test flight of the Orion spacecraft, designated Exploration Flight Test 1 (EFT-1). After several delays, the mission was successfully launched at 12:05 UTC on 5 December 2014.

On 12 August 2018, the Delta IV Heavy with an additional Star 48BV third stage was used to launch the Parker Solar Probe into an elliptical heliocentric orbit. In May 2023, the final Delta IV Heavy core and boosters finished construction, officially ending Delta IV production and making way for the Vulcan launch vehicle.

Capabilities

Capacity of the Delta IV Heavy:

The Delta IV Heavy's total mass at launch is approximately 733,000 kg (1,616,000 lb) and produce around 952,000 kg (2,099,000 lb) of thrust to power the rocket skyward at liftoff.

Launch history

Flight Date Payload Mass Launch site Outcome
1 21 December 2004 DemoSat, Sparkie / 3CS-1 and Ralphie / 3CS-2 ~13,228 pounds (6000 kilograms) Cape Canaveral, SLC-37B Partial failure
2 11 November 2007 DSP-23 Defense Support Program 11,574 pounds (5,250 kilograms) Cape Canaveral, SLC-37B Success
3 18 January 2009 Orion 6 / Mentor 4 (USA-202 / NROL-26) Classified Cape Canaveral, SLC-37B Success
4 21 November 2010 Orion 7 / Mentor 5 (USA-223 / NROL-32) Classified Cape Canaveral, SLC-37B Success
5 20 January 2011 KH-11 Kennen 15 (USA-224 / NROL-49) <37,479 pounds (17,000 kilograms) Vandenberg, SLC-6 Success
6 29 June 2012 Orion 8 / Mentor 6 (USA-237 / NROL-15) Classified Cape Canaveral, SLC-37B Success
7 26 August 2013 KH-11 Kennen 16 (USA-245 / NROL-65) <37,479 pounds (17,000 kilograms) Vandenberg, SLC-6 Success
8 5 December 2014 Orion Exploration Flight Test-1 (EFT-1) 46,297 pounds (21,000 kilograms) Cape Canaveral, SLC-37B Success
9 11 June 2016 Orion 9 / Mentor 7 (USA-268 / NROL-37) Classified Cape Canaveral, SLC-37B Success
10 12 August 2018 Parker Solar Probe 1,510 pounds (685 kilograms) Cape Canaveral, SLC-37B Success
11 19 January 2019 NROL-71 Classified Vandenberg, SLC-6 Success
12 11 December 2020 Orion 10 / Mentor 8 (USA-268/ NROL-44) Classified Cape Canaveral, SLC-37B Success
13 26 April 2021 KH-11 Kennen 17 (NROL-82) Classified Vandenberg, SLC-6 Success
14 24 September 2022 KH-11 Kennen 18 (NROL-91) Classified Vandenberg, SLC-6 Success
15 22 June 2023 Orion 11 / Mentor 9 (NROL-68) Classified Cape Canaveral, SLC-37B Success

Future launches

Missions thirteen through sixteen were announced by the National Reconnaissance Office. For the final five missions (12-16) including modifications, ULA was awarded US$2.2 billion, or US$440 million per launch. This can be compared with the Falcon Heavy launch price of $90M to $150M. As of June 2023, only one remains before ULA retires the Delta IV Heavy.

Flight Date Launch site Payload Mass Orbit Customer Launch
outcome
16 1 March 2024 CCSFS, SLC-37B NROL-70 Classified GEO US NRO Planned
Reconnaissance satellite, final flight of the Delta rocket family.
  1. CBCs underperformed, lower orbit than planned
  2. The officially reported mass of 21,000 kg includes the Launch Abort System (LAS) which did not reach orbit, but excludes the residual mass of the upper stage, which did reach orbit, likely offsetting the mass of the LAS.
  3. Star 48BV upper stage

Comparable vehicles

Current:

In development:

Retired or cancelled:

See also