United Launch Alliance has started assembling its next Vulcan rocket—the first destined to launch a US military payload—as the Space Force prepares to certify it to loft the Pentagon’s most precious national security satellites.
Space Force officials expect to approve ULA’s Vulcan rocket for military missions without requiring another test flight, despite an unusual problem on the rocket’s second demonstration flight earlier this month.
ULA has launched two Vulcan test flights. Military officials watched closely, gathering data to formally certify the rocket is reliable enough to launch national security missions. The first test flight in January, designated Cert-1, was nearly flawless. The Cert-2 launch October 4 overcame an anomaly on one of Vulcan’s strap-on solid rocket boosters, which lost its exhaust nozzle but kept firing with degraded thrust.
The rocket’s twin BE-4 main engines, made by Blue Origin, corrected for the asymmetric thrust from the two strap-on boosters. Vulcan’s Centaur V upper stage also fired its engines longer than planned to make up for the shortfall in performance from the damaged strap-on solid motor. Ultimately, the rocket reached its planned trajectory and delivered a dummy payload into interplanetary space.
A successful launch
Col. James Horne, who oversees launch execution for Space Systems Command, called the test flight a “successful launch” in an interview with Ars. The nozzle failure caused a “significant loss of thrust” from the damaged booster, he said.
The Vulcan rocket’s ability to overcome the dramatic nozzle failure, which was easily visible in video of the launch, “really demonstrated the robustness of the total Vulcan system,” Horne said.
“They nailed the orbit, probably one of the most accurate orbital insertions that I’ve seen them fly yet,” he said. “And at the end of the mission, they did some extended duration testing … which was not part of the orbital insertion. And even after that extended mission, they still had substantial performance reserve left over.”