ULA stacks first Vulcan in new facility as SRB test clears grounding hurdle

On May 14, ULA hoisted the first Vulcan booster into its newly completed Vertical Integration Facility–Amazon at Cape Canaveral Space Force Station. The moment was routine-sounding until you remember that ULA has not launched Vulcan since February 12, when one of Northrop Grumman's GEM 63XL solid rocket boosters suffered a nozzle burn-through 30 seconds into the USSF-87 mission. The booster's asymmetric thrust was real enough that the main BE-4 engines had to gimbal hard to arrest roll, but the payload still made orbit. Still, the space force grounded the vehicle. Three months later, with over 80 missions waiting to launch, ULA just stacked the first piece of hardware in a new physical lane. This is the first affirmative signal that the grounding is no longer a stall.

The SRB test itself passed. Gary Wentz, ULA's VP of Government and Commercial Programs, confirmed the ground test validated the motor's behavior under load without revealing specifics of what the test examined or what, exactly, had caused the nozzle breach. The bare fact, test passed, matters because it means ULA and Northrop Grumman have a hypothesis they can actually validate. The VIF-A facility matters because it is not a workaround; it is permanent infrastructure. ULA now operates two stacking lanes at the Cape: VIF-G for Atlas V or Vulcan, and VIF-A for Vulcan alone. Parallel stacking cuts integration time per booster and lets the company catch up on the manifest backlog once flights resume.

But the grounding itself remains unfinished. ULA's next step is a wet dress rehearsal, a full countdown without ignition, before return-to-flight. The company has not named a date. In the interim, the Space Force found a pressure release: Lt. Gen. Philip Garrant told reporters that certain missions do not require Vulcan's solid rocket boosters at all. A Space Development Agency mission, for example, has enough performance margin on the BE-4s alone to reach orbit. Those payloads can launch while the full SRB investigation continues. Amazon's Leo constellation missions are not among them, Leo needs the solid motors for the deltaV required. Amazon's next launch is scheduled for May 22 on an Atlas V, keeping that customer's schedule intact while Vulcan remains on hold.

The real constraint now is not engineering but credibility. ULA was contracted to launch 16 to 18 Vulcan missions in 2026. That target is already unachievable. The February grounding, the three-month stand-down, and the fact that return-to-flight remains conditional on a test campaign with no public deadline means customers are watching the calendar. For Amazon, which has Leo sats already stacked and waiting, the Atlas V buy at least moves payloads downrange. For the Space Force, the SDA workaround buys time without embarrassment. But the core problem persists: one booster manufacturer's nozzle failure has silenced the vehicle that was supposed to anchor U.S. heavy-lift capacity for the next decade. ULA's job now is to prove the grounding was the anomaly, not the beginning of a pattern.

Watch for three dates. First: when ULA announces the wet dress rehearsal window, that signals engineering confidence has moved from forensics to operational readiness. Second: the first return-to-flight mission name and date, which will tell you whether ULA expects to fly once before mid-year or is now targeting 2027. Third: whether Space Force launches any of those SDA missions without SRBs before Vulcan fully clears. If those light payloads actually fly, the grounding stops being a complete halt and becomes a managed rollback. That is not recovery. But it is not collapse either.