ULA’s Vulcan Gears Up for First Flight with Centaur Integration

United Launch Alliance recently announced that the Centaur V upper stage has been integrated into the first Vulcan rocket. This marks a major milestone towards the inaugural flight of the launch vehicle, currently scheduled for December 24, 2023.

Preparing for flight

The stage arrived at Cape Canaveral from ULA’s factory in Decatur, Alabama, aboard the company’s R/S Rocketship. The vessel transports all of their rockets to the respective launch sites. The Centaur V was then brought to the Vertical Integration Facility at Space Launch Complex 41 and hoisted on top of the booster stage.

*Centaur V being placed on top of the Vulcan booster inside the Vertical Integration Facility. Credits: ULA*

The upper stage thus joined the booster stage and the two GEM 63XL Solid Rocket Motors. These were stacked in late October and early November, respectively. Over the next few weeks, the stack will undergo testing of sub-systems and components. Then rollout to the pad will take place and a Wet Dress Rehearsal test will be conducted.

The mission, dubbed Cert-1, has the goal of launching Astrobotic’s Peregrine lunar lander to its lunar transfer orbit. The mission will allow the testing of the Vulcan rocket, and it will include three firings of the Centaur V upper stage. The spacecraft is part of the Commercial Lunar Payload Services program, under which NASA contracts private companies to perform lunar science and technology demonstration missions.

Vulcan development

Vulcan is ULA’s replacement for the Delta IV and Atlas V families of rockets. It sports a brand-new first stage, powered by Blue Origin’s methalox BE-4 engines. The GEM 63XL SRMs are an evolution of the boosters used on Atlas V, just like the Centaur V is an evolution of the stage that has flown on many rockets.

*Centaur V is unloaded from R/S Rocketship at Port Canaveral, having just arrived from Decatur, Alabama. Credits: ULA*

The development of the rocket has mostly gone smoothly, with the BE-4 engines by Blue Origin taking longer than expected. Nonetheless, they performed well during a static fire that took place in June. The Centaur V stage however caused trouble in March 2023, when a test article of the hydrolox-fuelled, pressure-stabilized stage suffered a hydrogen leak.

This ended up causing a launch delay. Following the conclusion of the investigation, the Centaur V was removed from the stack that had just completed static firing. The forward dome has since been reinforced to prevent a repeat of the anomaly.

*Astrobotic’s Peregrine lander that will launch on the first Vulcan flight. The spacecraft will study the local lunar environment. Credits: Astrobotics*

If all goes well, the launch should occur on December 24, 2023, at 06:49 UTC. Backup opportunities exist on December 25 and 26, or in January 2024. The orbital mechanics of the lunar flight dictate very strict launch windows. If all goes well, the second Vulcan flight should be Cert-2. It will carry the first Dream Chaser spaceplane, which was recently completed, into space. A success on both launches would qualify the rocket to fly for the US Space Force. Today’s milestone makes everything look much closer.