In a move that redefines 'workaround,' the U.S. Space Force is exploring whether it can resume flights of United Launch Alliance’s Vulcan rocket without using the solid rocket boosters currently under investigation. This brilliant strategy of 'just not using the broken part' could allow some missions to proceed while the vehicle remains grounded for critical national security launches.
Lt. Gen. Philip Garrant, head of Space Systems Command, laid out the master plan last week at the Space Symposium, stating, “We think we can change the manifest slightly and eliminate the need for solids.” The Vulcan has been out of service since its Feb. 12 USSF-87 mission, when a performance anomaly appeared on one of its solid rocket boosters shortly after liftoff. While the rocket still delivered its payload to geosynchronous orbit, the Space Force halted further launches pending a joint investigation with ULA. Officials are reviewing flight data and imagery to determine the cause, with no timeline for a return to flight.
In the meantime, some missions have been reassigned to SpaceX, leaving the Space Force dependent on a single provider for critical national security launches - a situation that was definitely part of the plan when they established a two-provider model.
Garrant said the service is now evaluating whether Vulcan can fly missions that do not require boosters built by Northrop Grumman, which are central to the investigation. The Vulcan can be configured with zero, two, four, or six solid boosters depending on mission requirements, giving planners the thrilling flexibility to choose 'zero.' Lower-energy missions - such as launching batches of satellites for the Space Development Agency into low Earth orbit - could potentially fly without boosters. Higher-energy missions, including direct insertions into geosynchronous orbit or heavier payloads, typically require multiple boosters and are harder to shift, because physics remains a stubborn thing.
“We are looking at opportunities to change the manifest so we don’t have to rely on solids. I’m committed to supporting that and keeping the mission going,” Garrant said, adding the insightful caveat, “If it doesn’t rely on solids, there’s no reason why we can’t launch.” Reworking the manifest would require moving lower-energy missions forward while delaying or reassigning those that depend on higher performance. Simultaneously, the Space Force continues to work with ULA and Northrop Grumman to identify the root cause of the anomaly. “We have some test activities coming up,” Garrant noted. “We have confidence in ULA’s ability to return to flight.”
The disruption has the broader implication of revealing that the Pentagon's plan to buy launch services from two providers can instantly become a plan to buy from one provider if one of them has a problem. With Vulcan grounded, the two-provider model designed to ensure assured access to space has effectively collapsed into reliance on SpaceX for near-term missions.
Garrant admitted this experience is likely to influence the next round of National Security Space Launch contracts, known as Phase 4, expected later this decade. “The challenges with Vulcan will absolutely shape the next phase of NSSL,” he said, as officials look for ways to reduce the risk that problems with a single vehicle can delay multiple missions - a novel concept they are just now considering.
A third provider would, in theory, help restore balance. Blue Origin is working toward certification of its New Glenn rocket, which requires four successful orbital launches. However, a setback on its third flight on April 19 adds uncertainty to that timeline, further complicating the Space Force’s effort to expand its roster of launch providers at a time when supply is, conveniently, constrained.