Independent Enquiry Commission Conclusions On Loss Of Vega-C Flight VV22

On Tuesday 20 December 2022, Arianespace announced the loss of the Vega-C VV22 mission after its launch at 22h47 local time in French Guiana (2h47 CET/1h47 GMT on 21 December 2022). The mission was carrying two payloads, Pléiades Neo 5 and 6 Earth observation satellites for Airbus Defence and Space.

Arianespace (the launch service provider) and the European Space Agency (ESA – the launch system development authority) immediately set up an Independent Enquiry Commission, which concluded that after the nominal functioning of the Vega-C first stage P120C and nominal ignition of the second stage (Zefiro 40), a progressive decrease in the chamber pressure was observed 151 seconds after lift-off, leading to the loss of the mission.

Initial investigations, conducted right after the launch with the available flight data, confirmed that the launcher’s sub-systems reacted to the events as designed, and that the cause of the failure was a gradual deterioration of the Zefiro 40’s nozzle. More precisely, the Commission confirmed that the cause was an unexpected thermo-mechanical over-erosion of the carbon-carbon (C-C) throat insert of the nozzle, procured by Avio in Ukraine. Additional investigations led to the conclusion that this was likely due to a flaw in the homogeneity of the material.

The anomaly also revealed that the criteria used to accept the C-C throat insert were not sufficient to demonstrate its flightworthiness. The Commission has therefore concluded that this specific C-C material can no longer be used for flight. No weakness in the design of Zefiro 40 has been revealed. Avio is implementing an immediate alternative solution for the Zefiro 40’s nozzle with another C-C material, manufactured by ArianeGroup, already in use for Vega’s Zefiro 23 and Zefiro 9 nozzles.

Considering the nature of the VV22 anomaly, the Commission emphasizes that its conclusions on Zefiro 40 do not affect the Vega launcher which is relying on the Zefiro 23 and Zefiro 9 motors. In this context, Arianespace decided to adapt its launch schedule to reassign a mission to one of its two remaining Vega launchers with a targeted launch date before the end of summer 2023.

The Independent Enquiry Commission has formulated a series of recommendations aiming at restoring confidence in the Vega and Vega-C launcher systems through the establishment of robust recovery plans to ensure a reliable return to flight and robust commercial exploitation.

The main strands of work based on the recommendations are:

• To complement the findings of the Commission with additional testing and analysis in order to ensure the robustness of the qualification of the alternative C-C material selected for Zefiro 40;
• To implement an additional qualification phase of the Zefiro 40 engine with the alternative C-C material;
• To implement a set of actions, aiming at guaranteeing a long-term reliable and sustainable launcher production.

A task force steered by ESA and Arianespace has started implementing the roadmap proposed by the Commission and will thoroughly follow the implementation of the actions by Vega’s prime contractor Avio, in order to ensure a reliable and robust return to flight of Vega-C. The targeted launch date is end of 2023.

ESA, as launch system qualification authority, Arianespace, as launch service provider and Avio, as design authority and prime contractor of the Vega launcher, will join their efforts to achieve the common objective of a robust exploitation of the Vega launch system, for the benefit of their institutional and commercial customers.

Josef Aschbacher, ESA Director General, said: “The Independent Enquiry Commission stands for ESA’s commitment to the highest safety standards. It has drawn a set of recommendations that once implemented should ensure a robust, reliable return to flight of the Vega-C launcher.

ESA will fully engage its engineering and project management expertise to support Avio in the implementation of actions required to regain confidence in the launcher system. Restoring Europe’s independent access to space is ESA’s priority, and I am therefore glad that we can proceed with Vega launch campaigns while preparing Vega-C to safely return to flight.”

“Thanks to their hard work, the members of the Commission have identified the immediate cause of the loss of the mission VV22 and of its lessons learnt, and proposed the relevant corrective actions,” said Stéphane Israël, CEO of Arianespace. “Their recommendations already are under implementation by Avio, under the supervision of Arianespace and ESA, in order to allow a successful return to flight of Vega-C and to guarantee its continuous reliability.”

About the European Space Agency

The European Space Agency (ESA) provides Europe’s gateway to space.

ESA is an intergovernmental organisation, created in 1975, with the mission to shape the development of Europe’s space capability and ensure that investment in space delivers benefits to the citizens of Europe and the world

ESA has 22 Member States: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland and the United Kingdom. Latvia, Lithuania, Slovakia and Slovenia are Associate Members.

ESA has established formal cooperation with four Member States of the EU. Canada takes part in some ESA programmes under a Cooperation Agreement.

By coordinating the financial and intellectual resources of its members, ESA can undertake programmes and activities far beyond the scope of any single European country. It is working in particular with the EU on implementing the Galileo and Copernicus programmes as well as with Eumetsat for the development of meteorological missions.

Learn more about ESA at www.esa.int

About Arianespace

Arianespace uses Space to make life better on Earth by providing launch services for all types of satellites into all orbits. It has orbited over 1,100 satellites since 1980. Arianespace is responsible for operating the new-generation Ariane 6 and Vega C launchers, developed by ESA, with respectively ArianeGroup and Avio as industrial primes. Arianespace is headquartered in Evry, near Paris, and has a technical facility at the Guiana Space Center in French Guiana, plus local offices in Washington, D.C., Tokyo and Singapore. Arianespace is a subsidiary of ArianeGroup, which holds 74% of its share capital, with the balance held by 15 other shareholders from the Ariane and Vega European launcher industry, and ESA and CNES as censors.

www.arianespace.com

For further information – ESA

Newsroom and Media Relations Office – Adelina Campos de Carvalho
Email: media@esa.int

For further information – Arianespace

Gregory Gavroy
E-mail: g.gavroy@arianespace.com

Cyrielle Bouju
E-mail: c.bouju@arianespace.com