Vulcan Centaur Completes Second Flight Despite Anomaly

On October 4th at 7:25 AM Eastern Time, United Launch Alliance’s Vulcan-Centaur rocket leaped off the pad for the second time, beginning a critical flight test ahead of a backlog of national security flights. According to ULA the mission’s various goals were completed, but not without incident.

Originally meant to carry the first of Sierra Space’s Dream Chaser spacecraft to the International Space Station, delays to the spacecraft’s ongoing integration and testing process ultimately resulted in a removal of the payload from this flight. The Cert-2 mission is a critical milestone for the Vulcan-Centaur rocket, and delays to the mission would bottleneck the vehicle’s future commitments. ULA and its parent companies have already received significant pressure to minimise schedule delays to the Vulcan-Centaur rocket’s operational timeline, including “postponement fees” sent by the Air Force over the summer. In place of Dream Chaser, the rocket carried various experiments and demonstrations paving the way for future upgrades to Centaur V upper stage – which ULA describes as “the world’s highest performing upper stage.”

The issue which presented itself in the first minute of Vulcan-Centaur’s Friday launch will likely be the system’s next challenge on the path to operational missions. Within seconds of lift off, one of Vulcan’s GEM-63XL boosters appeared to have a burn-through near the throat of its nozzle. The puncture continued until a progression of the issue seemingly liberated a large section of the nozzle or removed the nozzle entirely. ULA President and CEO Tory Bruno later claimed in a post on X, formally twitter, that regardless of the dramatic appearance no “No energetic,” (meaning explosive), “events occurred.” Despite the irregularity, Vulcan carried onwards, noticeably canted, but kept on track thanks to the gimbal of the core stage’s twin BE-4 engines.

Vulcan-Centaur continued through a successful SRB separation at two minutes and ten seconds into flight, with the damaged SRB losing thrust slightly ahead of its undamaged counterpart. Vulcan-Centaur had a nominal separation, with the Centaur V upper stage separating just past five minutes into flight. Centaur V completed two burns during Cert-2, the first placed it into orbit, and the second accelerated it to Earth escape velocity. Ejecting into heliocentric orbit (orbit of the Sun) is considered a valid method of disposal for a used stage under both NASA and Space Force sustainability and domain awareness guidelines. Remaining propellant was vented to pacify the stage fully, marking the end of the Cert-2 mission.

In a statement given to the press following the mission, ULA declared the mission successful and included statements from ULA President and CEO Tory Bruno indicating the Vulcan-Centaur system completed a “bullseye insertion” despite the anomaly. Bruno’s statement also acknowledged the apparent fault stating, “We had an observation on one of our solid rocket boosters that we are reviewing but we are overall pleased with the rocket’s performance.” In another statement released shortly after flight, Brig. Gen. Kristen Leigh Panzenhagen the Executive Officer of Assured Access to Space and Commander of Space Launch Delta 45 said “(The Space Force) is already starting to review the performance data from this launch, and we look forward to Vulcan meeting the certification requirements for a range of National Security Space missions.”

It is currently unclear how the incident which occurred during Vulcan-Centaur’s flight will affect the otherwise nominal execution of the Cert-2 mission, though it could potentially result in a delay to future flights. While writing this article a statement from the FAA was released in response to inquiries sent by NASASpaceflight indicating the agency is aware of the occurrence (described as “an anomaly”) and was still in the process of assessing the need for regulatory action. “The FAA is assessing the operation and will issue an updated statement if the agency determines an investigation is warranted.” Such an investigation would bar ULA from a speedy execution of its remaining Vulcan manifest for 2024, regardless of certification or the results of their own post-flight review. The results of all of these factors, of course, remains to be seen, and many questions remain unanswered as ULA looks forward to Vulcan’s third flight and cadence ramp up for 2025.

Cert-2 was certainly a more dramatic flight than had been anticipated, and in many ways encapsulates the highs and lows of space flight’s current epoch. New systems are approaching and entering the launch ecosystem, domestic and abroad, and even experienced parties are not above incidents. However, considering ULA’s long held commitment to a measured, safe approach to space flight, it is unlikely these events place Vulcan-Centaur’s future in jeopardy, even if it results in a change of plans.

Edited by Nik Alexander