ULA to Launch Vulcan Cert-2 Flight with no Payload

I have to admit I was a bit surprised to read that United Launch Alliance (ULA) is going to launch the second flight of their Vulcan launch vehicle without a payload in an attempt to complete their certification mission requirements for the US Space Force. 

The second flight of Vulcan, the Cert-2 mission, had been reserved for Sierra Space's Dream Chaser spacecraft for the last five years, and in light of what appeared to be Dream Chaser's successful test campaign this winter and spring at NASA's Neil Armstrong Test Facility in Sandusky, Ohio, I had been expecting Dream Chaser to be ready for an early fall launch. 

There's still a lot of work for Sierra Space to do to prepare the Dream Chaser spaceplane for launch. Sierra Space's chief executive, Tom Vice, recently told ULA that the Dream Chaser spaceplane will not be ready to fly by September, when ULA will have the next Vulcan rocket ready to go.

Tory Bruno, ULA's CEO, announced the change in flight plan for the second Vulcan rocket in a conference call with reporters.

“Timing is everything," Bruno said. "We waited as long as possible on Dream Chaser because we really, really wanted to fly them. It’s a very exciting mission.”

Instead, this is going to be a “Certification at our own expense” for ULA. Since no other payloads farther down the schedule are ready, the mission will carry a "dummy satellite" more commonly called dead weight. Ironically, that load was originally developed for the Cert-1 mission out of concern that its main payload, Astrobotic's Peregrine lunar lander, wouldn't be ready; the same situation going on here.

For the Cert-2 flight, Vulcan will fly in the same configuration as the successful Cert-1 mission, with two strap-on solid rocket boosters alongside Vulcan's two BE-4 engines from Blue Origin. Vulcan's upper stage, the Centaur V will then carry the load the rest of the way to Low Earth Orbit. 

"We'll do some maneuvers with the upper stage just to fully characterize the limits of what Centaur V can do," Bruno said. Future Vulcan missions will require the Centaur V upper stage to fly in space for six or more hours to place national security payloads directly into geosynchronous orbit more than 22,000 miles (nearly 36,000 kilometers) over the equator.

The Centaur V is based on the Centaur upper stage that flies on ULA's soon-to-be-retired Atlas V rocket, but it has larger propellant tanks and a second engine. ULA engineers will use the Centaur V demonstrations on the Cert-2 mission to measure how much super-cold liquid hydrogen and liquid oxygen propellants boil off in space. Ultimately, this data will help ULA determine Centaur V's endurance in orbit.

In essence, this is a learning exercise for ULA at their expense instead of one paid for by the customer's payload. From their standpoint, Space Force simply needs to see that ULA can repeat the success of the first Vulcan launch. Once Certification is granted, they could conceivably put a military payload on the third Vulcan flight before the end of the year. 

The Space Force is eager for Vulcan to become available for a backlog of 25 military launches it awarded to ULA beginning in 2020, when the first Vulcan flight was scheduled to happen in 2021. Instead, Vulcan didn't fly until this year, and there is urgency for ULA to complete the second Vulcan certification flight, known as Cert-2, as soon as possible.

Vulcan Centaur's Cert-1 flight lifts off on January 8, 2024 from SLC-40 at Cape Canaveral Space Force Station. Image credit: United Launch Alliance. 

At the end of the conference, Bruno gave a small update on their plans to reuse the BE-4 engines from each Vulcan flight. 

ULA is taking a dual-pronged approach with the engine reuse program. One line of work involves designing the detachable aft end of the Vulcan booster, which will separate from the rest of the rocket, reenter the atmosphere, and deploy a parachute for capture in mid-air. Bruno said the architecture for the separating engine pod recently passed a preliminary design review, a relatively early stage of development. For context, ULA completed the preliminary design review for the basic version of the Vulcan rocket in 2016, nearly eight years before it finally launched.
...
The other effort related to engine reuse is the development of an inflatable heat shield, with the help of NASA, to protect the Vulcan booster engines during reentry back into the atmosphere. ULA and NASA tested a half-scale model of the inflatable heat shield on a reentry in 2022 and are now working on a larger version.

Bruno added, "I know it’s not quite as photogenic as a propulsive first stage that flies back and lands," as SpaceX does and Blue Origin still plans to do with New Glenn.