ULA To Attempt Delta IV Heavy Launch After Infrastructure Repairs

Charles Boyer

2 years ago

United Launch Alliance is planning to launch the final launch of Delta IV Heavy on Tuesday from SLC-37 at Cape Canaveral Space Force Station. The launch window extends from 12:53 PM – 6:51 PM EDT. Delta IV was scrubbed at T-min 3:58 by a faulty gaseous nitrogen pump on its first attempt March 28, and since that time, NASA, the supplier of the material and ULA have worked to effect repairs and test the results to ensure another scrun doesn’t happen for that reason.

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.

A United Launch Alliance (ULA) Delta IV Heavy rocket is raised vertically at the Space Launch Complex-37 pad in preparation to launch the NROL-70 mission for the National Reconnaissance Office. Photo credit: United Launch Alliance

Weather

The 45th Weather Squadron rates today’s launch weather as very good, with only a 10% probability of a weather violation at launch time — meaning there is a 90% chance of acceptable weather.

Mission

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.”

United Launch Alliance has provided an excellent preview video for this launch:

Rocket

Delta IV Heavy is s the world’s third highest-capacity launch vehicle in operation, behind NASA’s SLS and SpaceX’s Falcon Heavy. Like SLS, Delta IV Heavy is fully expended during each mission, meaning no booster returns and landings.

United Launch Alliance graphic of Delta IV Heavy:
Credit: ULA

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.

Online Viewing

SpaceCoastLaunchCalendar.com will have a livestream of the launch if you’re not able to watch the launch in person: Livestream

Launch Viewing: In Person

The launch is from SLC-37 at Cape Canaveral, which means that the best direct views of liftoff are: Banana River Bridge on FL-528 W near Port Canaveral, or the southern parks on US-1 / S. Washington Avenue in Titusville. Kennedy Point Park and, Rotary Riverview Park (among others) are your best bets.

Cocoa Beach, Cocoa Beach Pier, Jetty Park Pier will have indirect views, meaning that liftoff will not be visible, but after the rocket clears the pad and any ground obstructions, you will be able to see Falcon 9 ascending clearly assuming there are no clouds between you and the rocket.