ULA’s Vulcan rocket still doesn’t have the Space Force’s seal of approval

Last October, United Launch Alliance started stacking its third Vulcan rocket on a mobile launch platform in Florida in preparation for a mission for the US Space Force by the end of the year.

That didn't happen, and ULA is still awaiting the Space Force's formal certification of its new rocket, further pushing out delivery schedules for numerous military satellites booked to fly to orbit on the Vulcan launcher.

Now, several months after stacking the next Vulcan rocket, ULA has started taking it apart. First reported by Spaceflight Now, the "de-stacking" will clear ULA's vertical hangar for assembly of an Atlas V rocket—the Vulcan's predecessor—to launch the first batch of operational satellites for Amazon's Kuiper Internet constellation.

This involves removing the rocket's Centaur upper stage, interstage adapter, and booster stage from its launch mount. ULA's facilities at Cape Canaveral Space Force Station, Florida, can only handle stacking one rocket at a time. A second assembly building will double this capacity when it comes online later this year.

ULA hoped to launch as many as 20 missions in 2025, with roughly an even split between its new Vulcan rocket and the Atlas V heading for retirement. That would require around one launch every two and a half weeks. Six weeks into 2025, ULA's first launch of the year is still a month or more away.

More than crossing T’s and dotting I’s

The laborious process of certifying a new rocket or spacecraft involves numerous reviews and metaphorical stacks of paperwork. The Space Force's objective with certifying the Vulcan rocket is ensuring it will provide a reliable ride to orbit for the military's most sensitive and expensive satellites. These include spy satellites, missile warning sentinels, and spacecraft for the Global Positioning System.

In 2020, the Pentagon awarded ULA and SpaceX multibillion-dollar "Phase 2" contracts to share responsibilities for launching dozens of national security space missions. At that time, these launches were projected to fly by the end of 2027, although that's unlikely to happen now.

The Space Force awarded ULA 26 missions worth $4.5 billion under the Phase 2 contract, while 22 missions went to SpaceX's Falcon 9 and Falcon Heavy. SpaceX started delivering on its Phase 2 contract in January 2023. The first of ULA's Phase 2 missions launched last year on an Atlas V rocket, and 25 more are slated to fly on Vulcan.

Pentagon officials haven't been pleased with ULA's progress on the Vulcan rocket. The most evident sign of the discontent came in the form of a letter last year to Boeing and Lockheed Martin, ULA's co-owners.

Frank Calvelli, then the Air Force's assistant secretary for space acquisition and integration, wrote that he was "growing concerned with ULA’s ability to scale manufacturing of its Vulcan rocket and scale its launch cadence to meet our needs."

Development setbacks delayed the first Vulcan launch by about four years before ULA successfully completed the rocket's first demonstration flight in January 2024. At that time, ULA expected to be ready to launch the first military mission on the Vulcan rocket in mid-2024, plus two more by the end of the year. Those missions are still waiting for their ride to space.

"Currently there is military satellite capability sitting on the ground due to Vulcan delays," Calvelli wrote.

A second Vulcan test flight launched on October 4, and while the rocket reached its targeted orbit, it overcame a malfunction in one of the rocket's two solid rocket boosters, which lost its exhaust nozzle moments after liftoff.

The problem prompted an engineering investigation in parallel with the Space Force's certification process, which required two successful flights before clearing Vulcan for operational service. This eliminated any chance of launching the first Vulcan flight for the Space Force by the end of 2024.

Tory Bruno, ULA's CEO, told reporters in December that engineers have a "pretty good idea of what happened" with the Northrop Grumman-built solid rocket booster, and boosters already in ULA's inventory will require "minor modifications" to fix the problem. "There are insulators that failed that are bonded to the inside of the shell that becomes the nozzle, and we recovered parts of those," Bruno said.

The first national security mission on Vulcan, designated USSF-106, is set to deploy an experimental navigation satellite for the Air Force Research Laboratory.