Note: I could not attend this launch, as I was traveling to Texas for the solar eclipse. I was accredited press, however, and was able to photograph the rocket on a few occasions prior to its launch on April 9, 2004. Words and photos were originally published by me at Talk of Titusville and are reprinted here by permission.

United Launch Alliance is planning to launch the final launch of Delta IV Heavy on Thursday from SLC-37 at Cape Canaveral Space Force Station. The launch window extends from 1:40 PM – 6:51 PM EDT. NROL-70 is a mission is set to carry a classified payload for the National Reconnaissance Office, an agency of the United States Department of Defense.

This will be the 16th Delta IV Heavy launch, the 39th orbital launch attempt from SLC-37 and the 941st from Cape Canaveral.

After this launch, SLC-37 will no longer have a rocket assigned to it, meaning that the pad can be reconfigured for other missions. In February, the Department of the Air Force announced an Environmental Impact Study for potentially using the launch complex for SpaceX Starship operations. SLC-37 is one of three choices – the other two being building a new SLC-50 and also not using CCSFS for Starship operations. In their EIS materials, the DAF say they will make a final decision in 2025 in the matter.

Payload

Not much is known about the specific payload, which is no surprise given that is classified. In other words, the general public does not meet the criteria for need-to-know and therefore only the most basic descriptions are available.

According to ULA, “The NROL-70 mission will strengthen the NRO’s ability to provide a wide-range of timely intelligence information to national decision makers, warfighters, and intelligence analysts to protect the nation’s vital interests and support humanitarian efforts worldwide.”

It consists of three core rockets, all liquid-fueled, and with one Hydrogen-Oxygen powered Aerojet Rocketdyne RS-68A engine on each core. According to AR, the RS-68A “”Produces more than 17 million horsepower” and it is the “World’s largest and highest thrust hydrogen-fueled engine.”

At ignition, Delta IV Heavy has a unique appearance because of hydrogen flow to the engines, which then escapes outward and upward the booster body, where it ignites and gives Delta IV Heavy its unique “setting itself on fire” and charred look.

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 at liftoff, making it a powerful machine indeed.

The lift capacity of Delta IV Heavy is

• Low Earth orbit (LEO): 28,790 kg (63,470 lb)
• Geosynchronous transfer orbit (GTO): 14,220 kg (31,350
• Geosynchronous orbit (GEO): 6,750 kg (14,880 lb)
• Lunar transfer orbit (LTO): 10,000 kg (22,000 lb)
• Mars transfer orbit: 8,000 kg (18,000 lb)

It costs approximately $350 Million per mission, making it one of the most expensive rockets in current operation.