Delta IV Heavy

History

The Delta IV program was initiated by Boeing under the U.S. Air Force's Evolved Expendable Launch Vehicle program and was transferred to ULA in 2006. The Delta IV Heavy was developed as the most powerful configuration of the family, complementing the smaller Delta IV Medium.

Its maiden flight on December 21, 2004 carried a boilerplate payload and ended in partial failure when cavitation in liquid-oxygen lines caused premature shutdown of the engines, leaving the test article in a lower-than-intended orbit. The rocket achieved its first fully successful operational flight in 2007 with the launch of the DSP-23 satellite, and subsequently deployed several reconnaissance satellites for the National Reconnaissance Office (NRO).

The rocket was also used for two notable missions for NASA, Exploration Flight Test-1, the first uncrewed test of the Orion spacecraft in 2014, and the Parker Solar Probe launch in 2018, which required an additional Star 48BV third stage to achieve its elliptical heliocentric orbit.

Production of Delta IV Heavy hardware ended in May 2023, with its last mission flying for the NRO on April 9, 2024.

Capabilities

At liftoff, the rocket had a mass of approximately 733000 kg and generated about 9420 kN of thrust.

The Delta IV Heavy had the following payload capacities:

;Notes

A 67.2 ft carbon composite bisector payload faring was standard. The Delta IV with the extended fairing was over 62 m tall.

An aluminum isogrid trisector fairing, derived from a Titan IV fairing, was also available as an option. The trisector fairing was first used on the DSP-23 flight.

Launch history

Comparable vehicles

Current:

• Long March 5 (geostationary transfer orbit)
• Long March 5B (low Earth orbit)
• Long March 7A (geostationary transfer orbit)
• Falcon Heavy
• Proton-M
• Vulcan Centaur
• Angara A5
• Ariane 6
• New Glenn

Retired or cancelled:

• Ariane 5 (retired)
• Atlas V Heavy (proposed, never developed)
• Saturn IB (retired)
• Titan III (retired)
• Titan IV (retired)

References

References

1. "ULA CEO Tory Bruno".
2. "Delta IV Heavy".
3. (March 27, 2024). "The Delta IV Heavy, a rocket whose time has come and gone, will fly once more".
4. (February 6, 2018). "Falcon Heavy, SpaceX's Big New Rocket, Succeeds in Its First Test Launch". The New York Times.
5. "Mission Status Center". Spaceflight Now.
6. (August 24, 2020). "ULA to launch Delta 4 Heavy for its 12th mission, four more to go before rocket is retired". SpaceNews.
7. (February 9, 2024). "Delta IV Heavy - NROL-70". Next Spaceflight.
8. "Delta IV Payload Planner's Guide, June 2013". United Launch Alliance.
9. (August 26, 2020). "Delta 4-Heavy likely heading for geosynchronous orbit with top secret payload". Spaceflight Now.
10. Berger. (January 21, 2019). "This massive rocket creates a fireball as it launches, and that's by design".
11. Howell, Elizabeth. (April 20, 2018). "Delta IV Heavy: Powerful Launch Vehicle". Space.com.
12. (March 16, 2005). "Delta 4-Heavy investigation identifies rocket's problem". Spaceflight Now.
13. (December 5, 2014). "Second Stage Ignites as First Stage Falls Away".
14. "Delta IV Parker Solar Probe".
15. "ULA's Delta rocket assembly line falls silent".
16. (April 9, 2024). "'Heavy' history: ULA launches final Delta rocket after 64 years (video, photos)".
17. (August 29, 2020). "Live coverage: Launch of Delta 4-Heavy rocket set for early Saturday". Spaceflight Now.
18. "Vulcan Centaur Cutaway Poster". ULA.
19. (December 7, 2004). "The Heavy: Triple-sized Delta 4 rocket to debut". Spaceflight Now.
20. (September 2007). "Delta IV Payload Planners Guide". United Launch Alliance.
21. link. (April 27, 2014)