ULA Examines Fragments from Vulcan Rocket’s Impaired Booster Nozzle

ULA Examines Fragments from Vulcan Rocket's Impaired Booster Nozzle

ULA Examines Fragments from Vulcan Rocket’s Impaired Booster Nozzle


### Vulcan Rocket’s Booster Anomaly: A Setback, Yet Not a Roadblock

On October 4, 2024, United Launch Alliance’s (ULA) second Vulcan rocket successfully launched from Cape Canaveral Space Force Station in Florida, representing another advancement in the development of this next-generation launch system. However, shortly following its ascent, the mission faced an unforeseen issue: the nozzle of one of the two solid rocket boosters (SRBs) malfunctioned, resulting in debris being scattered along the Florida coast. Regardless of this anomaly, the Vulcan rocket maintained its ascent and achieved its targeted trajectory, showcasing the vehicle’s resilience and the strength of its design.

### The Incident: An In-Depth Examination

The failure took place about 37 seconds after liftoff when the nozzle of one of the Vulcan’s strap-on boosters, a Graphite Epoxy Motor (GEM) 63XL, separated from the rocket. This resulted in a conspicuous display of sparks and debris, as recorded by tracking cameras. The nozzle, a vital part that directs exhaust gases and generates thrust, is secured to the bottom of the booster casing. Its failure led to a notable decrease in thrust from that specific booster.

In spite of the malfunction, the Vulcan rocket’s core stage engines, powered by two BE-4 engines from Blue Origin, compensated for the lost thrust. The rocket momentarily tilted due to uneven thrust but quickly regained its correct trajectory, continuing its voyage into space. ULA verified that the rocket ultimately attained its intended path, albeit with a slightly extended burn time from its core stage and Centaur upper stage engines.

### Investigating the Root Cause

United Launch Alliance, alongside Northrop Grumman, the producer of the GEM 63XL solid rocket boosters, has launched an investigation into the circumstances surrounding the nozzle failure. ULA spokesperson Julie Arnold confirmed that the company has retrieved some smaller fragments of the booster nozzle from the launch pad area. These fragments are currently under analysis as part of the ongoing inquiry.

The GEM 63XL booster represents an enhanced version of the solid rocket motors previously used on ULA’s Atlas V rocket, which Vulcan is intended to replace. Northrop Grumman’s GEM series motors have a long track record of dependability, with the last notable failure taking place in 1997 when a GEM 40 motor broke apart during a Delta II rocket launch.

### The Significance of Vulcan’s Test Flights

The launch on October 4 marked the second test flight of the Vulcan rocket, following a nearly flawless inaugural flight in January 2024. This test flight was executed without a payload, as Sierra Space’s Dream Chaser spaceplane, initially planned for this mission, was unprepared for launch. Consequently, ULA decided to carry a dummy payload to facilitate the test flight, which is vital for the rocket’s certification by the U.S. Space Force.

The Space Force mandates two successful test flights prior to certifying Vulcan for operational duties, especially for deploying military satellites. Notwithstanding the booster anomaly, ULA CEO Tory Bruno expressed assurance in the rocket’s performance, indicating that the BE-4 engines compensated for the thrust reduction from the faulty booster. Bruno stressed that while the rocket experienced a temporary deviation from its intended path, it promptly rectified itself and accomplished the mission successfully.

### A Resilient Rocket

The Vulcan rocket’s capability to recover from the booster malfunction and still attain its intended trajectory is a strong indicator of its robust design. Bruno referred to the Vulcan as “a beast,” underlining the vehicle’s ability to manage unexpected obstacles. The core stage and upper stage engines operated for an additional 20 seconds to offset the thrust deficiency, guaranteeing the success of the mission.

However, questions linger regarding whether the rocket would have achieved the same outcome if it were carrying a heavier operational payload, such as a military satellite. The dummy payload utilized in the test flight was considerably lighter than the payloads Vulcan will ultimately transport on operational missions.

### Looking Forward: Upcoming Vulcan Missions

In spite of the setback, ULA remains positive about Vulcan’s future. The company has 35 GEM 63XL boosters prepared for future missions, and each Vulcan flight has the capacity for up to six strap-on boosters, in accordance with mission needs. Bruno conveyed confidence that the investigation into the booster anomaly will be concluded swiftly, permitting ULA to proceed with its scheduled launches.

The forthcoming major milestones for Vulcan include two operational flights for the U.S. Space Force. The first mission, known as USSF-106, is set to launch an experimental navigation satellite into orbit for the Air Force Research Laboratory. The second mission, USSF-87, will deploy two Space Force satellites intended for monitoring other spacecraft in geosynchronous orbit.

### Conclusion: A Minor Hiccup, But Not a Detour

While the nozzle failure during the Vulcan rocket’s second test flight was an unexpected challenge,