Delta IV Heavy


The Delta IV Heavy is an expendable heavy-lift launch vehicle, the largest type of the Delta IV family and the world's second highest-capacity rocket in operation, behind SpaceX's Falcon Heavy rocket. It is manufactured by United Launch Alliance and was first launched in 2004.
The Delta IV Heavy consists of a central Common Booster Core, 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 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 rocket uses 3 RS-68 engines, one in the central core and one in each booster.

History

The Delta IV line of rockets was developed by McDonnell Douglas, later 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 to low Earth orbit and 13,810 kg to geostationary transfer orbit. It is an all liquid-fueled rocket, consisting of an upper stage, one main booster and two strap-on boosters.
The first launch of the Delta IV Heavy in 2004 carried a boilerplate payload and failed to reach intended orbit. 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 through 2013.
In December 2014, the Delta IV Heavy was used to launch an uncrewed test flight of the Orion spacecraft, designated EFT-1. After several delays on December 4, the mission was successfully launched at 12:05 UTC on December 5.

Capability

Capacity of the Delta IV Heavy:
The Delta IV Heavy's total mass at launch is approximately.

Launch history

Flight No.DatePayloadMassLaunch siteOutcome
1December 21, 2004DemoSat, Sparkie / 3CS-1 and Ralphie / 3CS-2~6000 kgCape Canaveral
2November 11, 2007DSP-23 Defense Support Program5,250 kgCape Canaveral
3January 18, 2009Orion 6 / Mentor 4 Cape Canaveral
4November 21, 2010Orion 7 / Mentor 5 Cape Canaveral
5January 20, 2011KH-11 Kennen 15 <17,000 kgVandenberg
6June 29, 2012Orion 8 / Mentor 6 Cape Canaveral
7August 28, 2013KH-11 Kennen 16 <17,000 kgVandenberg
8December 05, 2014Orion capsule Exploration Flight Test 1 Cape Canaveral
9June 11, 2016Orion 9 / Mentor 7 Cape Canaveral
10August 12, 2018Parker Solar Probe685 kgCape Canaveral
11January 19, 2019NROL-71Vandenberg

Upcoming launches

The following missions have been announced by the National Reconnaissance Office. As of May 2020, these are the final five missions.
For these missions including modifications, ULA has been awarded $2.2 billion, or $440 million per launch.
Date PayloadClientLaunch site
26 August 2020NROL-44NROCape Canaveral, SLC-37B
October 2020NROL-82NROVandenberg, SLC-6
H2 2022NROL-91NROVandenberg, SLC-6
H2 2022NROL-70NROCape Canaveral, SLC-37B
H2 2023NROL-68NROCape Canaveral, SLC-37B

Comparable vehicles

Current:
Development:
Retired or cancelled: