ESA has established an Independent Enquiry Commission to investigate the failure of the Avio-led Vega C Zefiro 40 (Z40) static fire test.
“An Independent Enquiry Commission has been established by ESA Director General Josef Aschbacher to investigate the recent results of the static firing test of the Vega-C Zefiro 40 motor, which took place on 28 June 2023,” an ESA spokesperson told European Spaceflight. “The commission is chaired by ESA Inspector General Giovanni Colangelo.”
According to an Avio, the Z40 motor failed 40 seconds into the test with the team observing a “reduction in overall pressure performance of the motor.” The Independent Enquiry Commission that investigated the failure of the Vega C V22 flight in December 2022 found that there had been a progressive decrease in the chamber pressure aboard the Z40 motor observed 151 seconds after lift-off, which would have been around 30 seconds into the ignition of the second stage. The commission found that the over-erosion of the motor’s throat insert had been the cause of the loss of pressure. Despite the similarities between the two failures, Avio has stated that the new throat insert, which is now supplied by ArianeGroup, “showed a nominal performance.”
Progress on returning Vega C to flight will be halted until the Independent Enquiry Commission has concluded its investigation. This will likely push its return back to Q1 2024 at the earliest. The best-case scenario is that the commission finds that the test conditions were overly extreme and were not a reflection of flight conditions. Additionally, as the test was primarily focused on verifying that the throat insert was fit for flight (which it appears it way), there may be a path through this that does not include redesigning or retesting the stage. Even if this is the case, customer confidence in the vehicle will undoubtedly have taken a knock.
