Bruno said engineers attributed the problem to a manufacturing defect in the solid rocket motor insulator, and telemetry data from all four boosters on the next flight in August showed “accurate” performance. But officials decided to take back the used, disposable engine casings from the Atlantic Ocean for inspection to make sure there were no other surprises or problems.
The hiccup delaying Vulcan's next launches is not related to rocket production. ULA has equipment for several Vulcan rockets stored at the Space Force Station in Cape Canaveral, Florida.
Instead, one of the key reasons for Vulcan's past delays has been the performance of the rocket, especially its solid rocket boosters. It's unclear whether the latest delays are related to the readiness of the Space Force's GSSAP satellites (the next GPS satellite to fly on Vulcan is available for launch in 2022), testing of Vulcan's solid rocket motors, or something else.
Vulcan rocket cores in storage at Cape Canaveral Space Force Station, Florida.
Photo: United Launch Alliance.
A Space Systems Command spokesperson told Ars that “appropriate measures are being taken to ensure the success of the USSF-87 mission…Teams are reviewing all equipment, as well as available data from previous missions, to evaluate the spaceflight suitability of future missions.”
The spokesperson did not give a specific answer to Ars' question about solid-fuel engine inspections on Vulcan's latest flight.
ULA's outfitting of a new rocket assembly hangar and a second mobile launch platform for the Vulcan rocket at Cape Canaveral has also been delayed. With so many launches in its portfolio, ULA needs the capacity to stack and prepare at least two rockets in different buildings at the same time. Ultimately, the company's goal is to release videos on average twice a month.
On Monday, ground crews at Cape Canaveral the second Vulcan launch platform was moved to the company's launch pad for compliance testing and “initial technical testing.” This is a good sign that the company is getting closer to ramping up the pace of its Vulcan launch, but it's now clear that won't happen this year.
Vulcan's slow launch rate since its first flight in January 2024 is not unusual for new rockets. SpaceX's Falcon 9 and ULA's Atlas V took 28 months to complete their fourth flight, while Vulcan will reach that deadline in May 2026.
ULA's Delta IV rocket made its fourth flight 25 months after its debut in 2002. Europe's Ariane 6 rocket has made its fourth flight in 16 months, but it has more in common with its predecessor than the others. SpaceX's Starship also picked up speed, with its fourth test flight taking place less than 14 months after its first.
