 | |
.jpg) Delta IV Heavy launches from Vandenberg Space Force Base | |
| Function | Orbital heavy-lift launch vehicle |
|---|---|
| Manufacturer | United Launch Alliance |
| Country of origin | United States |
| Cost per launch | US$350 million[1] NRO: US$440 million |
| Size | |
| Height | 70.7 m (232 ft) |
| Diameter | 5.1 m (17 ft) |
| Width | 15.3 m (50 ft) |
| Mass | 733,000 kg (1,616,000 lb) |
| Stages | 2+ |
| Capacity | |
| Payload to LEO | |
| Mass | 28,790 kg (63,470 lb) |
| Payload to GEO | |
| Mass | 6,750 kg (14,880 lb) |
| Associated rockets | |
| Family | Delta |
| Comparable | |
| Launch history | |
| Status | Retired |
| Launch sites | |
| Total launches | 16 |
| Success(es) | 15 |
| Partial failure(s) | 1 |
| First flight | 21 December 2004 (USA-181) |
| Last flight | 9 April 2024 (NROL-70) |
| 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)[2] |
| 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[3] |
| 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) (LH2 tank) 3.2 m (10 ft) (LOX tank)[4] |
| 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 | 465.5 s (4.565 km/s) |
| Burn time | 1125 seconds |
| Propellant | LH2 / LOX |
The Delta IV Heavy (Delta 9250H) was an expendable heavy-lift launch vehicle, the largest type of the Delta IV family. It had the highest capacity of any operational launch vehicle in the world after the retirement of the Space Shuttle in 2011 until the Falcon Heavy debuted in 2018, and it was the world's third highest-capacity launch vehicle in operation at the time of its retirement in 2024.[5][6][7] It was manufactured by United Launch Alliance (ULA) and was first launched in 2004.[8] Delta IV Heavy was the last operating member of the Delta IV family, and its final flight was on 9 April 2024. Future ULA launches will use the Vulcan Centaur rocket.[9][10]
The Delta IV Heavy first stage consisted 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 rocket engines would operate at full thrust, and 44 seconds later the central engine would throttle down to 55% to conserve fuel until the other two engines separate. The latter engines burn out at 242 seconds after launch and are separated as the central engine throttles back up to full thrust. The central engine burns out 86 seconds later, and the second stage completed the ascent to orbit.[3]
The launch vehicle used three RS-68 engines, one in the central core and one in each booster.[11] On the last seconds of countdown, the liquid hydrogen fuel would flow through the engines and upwards along the booster body, and after the ignition that hydrogen inflamed, creating the characteristic fireball and charred look of the booster.[12]
- ^ "ULA CEO Tory Bruno". twitter.com. Retrieved 12 February 2018.
Delta IV Heavy goes for about US$350M. That's current and future, after the retirement of both Delta IV Medium and Delta II.
- ^ "Delta IV Heavy". Spaceflight 101. Retrieved 26 July 2014.
- ^ a b "Delta IV Payload Planner's Guide, June 2013" (PDF). United Launch Alliance. Archived from the original (PDF) on 10 July 2014. Retrieved 26 July 2014.
- ^ "Delta IV Launch Services User's Guide" (PDF). United Launch Alliance. Retrieved 13 April 2024.
- ^ Clark, Stephen. "The Delta IV Heavy, a rocket whose time has come and gone, will fly once more". ars Technica. Retrieved 9 November 2024.
- ^ Chang, Kenneth (6 February 2018). "Falcon Heavy, SpaceX's Big New Rocket, Succeeds in Its First Test Launch". The New York Times. Retrieved 6 February 2018.
The Falcon Heavy is capable of lifting 140,000 pounds to low Earth orbit, more than any other rocket today.
- ^ "Mission Status Center". Spaceflight Now. Retrieved 26 July 2014.
The ULA Delta 4-Heavy is currently the world's largest rocket, providing the nation with reliable, proven, heavy lift capability for our country's national security payloads from both the east and west coasts.
- ^ "Boeing Delta IV Heavy Achieves Major Test Objectives in First Flight" (Press release). Boeing. 21 December 2004. Archived from the original on 19 April 2012. Retrieved 22 March 2012.
- ^ Erwin, Sandra (24 August 2020). "ULA to launch Delta 4 Heavy for its 12th mission, four more to go before rocket is retired". SpaceNews. Retrieved 29 August 2020.
- ^ "Delta IV Heavy - NROL-70". Next Spaceflight. 9 February 2024. Retrieved 10 February 2024.
- ^ "Delta 4-Heavy likely heading for geosynchronous orbit with top secret payload". Spaceflight Now. 26 August 2020. Retrieved 27 August 2020.
- ^ Berger, Eric (21 January 2019). "This massive rocket creates a fireball as it launches, and that's by design". Ars Technica. Retrieved 13 April 2023.