NROL-70: Final Delta IV Heavy prepared for launch

March 12, 2024


The dependable Delta — one of the pillars in American rocketry for more than 60 years — is preparing for its final mission that will carry a national security payload into space to serve and protect the U.S. and our allies.

United Launch Alliance (ULA) will use a Delta IV Heavy rocket to launch the NROL-70 mission in service to the National Reconnaissance Office (NRO) and support for the U.S. Space Force's Space Systems Command (SSC).

Liftoff is planned for Thursday, March 28 from Space Launch Complex (SLC)-37 at Cape Canaveral Space Force Station, Florida.

This will be the 16th flight of the Delta IV Heavy launch vehicle and 389th and final flight of the Delta program.

Delta IV Heavy is readied for NROL-70. Photo by United Launch AllianceNROL-70 extends a partnership between the NRO and ULA that began with our very first launch in 2006 and now totals 34 consecutive successes. This will be ULA's 35th NRO launch.

The triple-core Delta IV Heavy is the only operational rocket in the world today that possesses all necessary attributes to meet the stringent requirements to perform the NROL-70 mission. It will be the NRO's 12th launch aboard ULA's heavy-performance rocket, which is recognized for delivering high-priority missions for national security and NASA. The rocket first flew in December 2004.

The payload aboard NROL-70 is designed, built and operated by the NRO in support of the agency's national security mission to provide intelligence data to U.S. senior policy makers, the Intelligence Community and Department of Defense.

When the U.S. needs eyes and ears in critical places where no human can reach – be it over the most rugged terrain or through the most hostile territory – it turns to the NRO. The NRO is the U.S. government agency tasked with designing, building, launching and maintaining America’s intelligence satellites. Whether creating the latest innovations in satellite technology, contracting with the most cost-efficient industrial suppliers, conducting rigorous launch schedules, or providing the highest-quality products to our customers, the NRO never loses focus on who they are working to protect: our nation and its citizens.

Beginning in 1961 to declassification to the public in 1992, the NRO continues to work tirelessly to provide the best reconnaissance support possible to the Intelligence Community and Department of Defense.

The Delta IV Heavy emerges from RocketShip at Port Canaveral. Photo by United Launch Alliance

Preparations for the NROL-70 launch began with the May 2023 delivery of the rocket from the ULA factory in Decatur, Alabama, to Cape Canaveral via the R/S RocketShip, our ocean-going cargo vessel that transports rocket elements to the launch sites.

The final Delta arrived exactly 22 years after the first Delta IV, called the static fire test unit, arrived at the Cape for early pathfinder activities.

Delta IV Heavy consists of a half-million pounds (227,000 kg) of hardware in the form of three common booster cores (CBCs) fitted with RS-68A main engines, a Delta Cryogenic Second Stage (DCSS) with an RL10C-2-1 engine and a metallic trisector payload fairing (PLF) that is 16.7 feet (5.1 meters) in diameter and 65 feet (19.8 meters) in length.

The rocket uses liquid hydrogen and liquid oxygen in all stages, with each RS-68A main engine generating 702,000 pounds (312.3 kiloNewtons) of thrust and generating a combined 2.1 million pounds (9.4 mega-Newtons) of liftoff thrust, and the RL10C-2-1 upper stage engine producing 24,750 pounds (106.7 Newtons) of thrust.

Testing and connection of the stages took place within the Horizontal Integration Facility (HIF) adjacent from the launch pad. The port and starboard boosters were attached to the center core, then the DCSS was joined to the interstage on the forward end of the center booster.

Also completed in the HIF, the Launch Mate Unit (LMU) was fastened to the three CBCs to serve as the structural base of the rocket when it stands atop on the pad's launch table. The LMU contains the 12 holddown bolts that fire to release the fully fueled, 1.6-million-pound (725,700-kg) rocket at liftoff.

The Delta IV Heavy rolls out for NROL-70. Photo by United Launch Alliance

The 170-foot-long (51.8-meter) rocket then emerged from the HIF on Dec. 19, 2023, riding horizontally aboard a 36-wheel, diesel-powered transporter down the roadway to the launch pad.

The Fixed Pad Erector raised the vehicle upright at the pad on Dec. 20, 2023 to complete the Launch Vehicle on Stand (LVOS) milestone in preparation for Delta IV Heavy to launch NROL-70.

Integrated operations began Feb. 26 as encapsulated NROL-70 payload was delivered to the pad and hoisted atop the rocket, finishing assembly of the 235-foot-tall (71.6-meter) Delta IV Heavy and kicking off the final phase of the launch campaign.

The encapsulated payload is hoisted into the tower for attachment to Delta IV Heavy. Photo by United Launch Alliance
NROL-70 will be the 389th Delta launch since 1960, the 45th Delta IV and 16th in the Heavy configuration. It also marks the 294th launch of a Delta rocket from Cape Canaveral and the 35th for the Delta IV.

This is the final Delta IV Heavy as ULA transitions its future missions from the East and West Coasts to the new Vulcan rocket. A single-core Vulcan is our next generation launch solution that offers accessibility and even higher performance to launch heavy-class missions for the nation.

Learn more about the Delta IV Heavy/NROL-70 launch

See our NROL-70 photo album