Delta IV Heavy
The most powerful American rocket before Falcon Heavy. Delta IV Heavy launched the Parker Solar Probe, the Orion EFT-1 test flight, and numerous classified national security payloads. Its distinctive fireball at ignition, caused by excess hydrogen burning off, made it one of the most visually dramatic rockets ever launched.
History
Delta IV Heavy used three Common Booster Cores, each powered by an Aerojet Rocketdyne RS-68A engine burning liquid hydrogen and liquid oxygen. It was the only American heavy-lift vehicle available for the most critical national security payloads and high-energy interplanetary missions.
The rocket''s signature visual feature was a fireball that engulfed the base of the vehicle at ignition, caused by gaseous hydrogen burning off before the engines reached full thrust. This looked alarming but was a normal part of the launch sequence.
Delta IV Heavy made its final flight on April 9, 2024, closing out the Delta rocket family after six decades. Its retirement transferred heavy-lift responsibilities to SpaceX''s Falcon Heavy and ULA''s Vulcan Centaur.
Timeline
Launch Heritage
- Parker Solar Probe
- Orion EFT-1
- NROL missions
Technical Specifications
Tags
Designed by Boeing / ULA
