In March, 2023, the last ever Ariane 5 EAP (Etage d'Acceleration à Poudre, or Solid Rocket Booster in English) was completed at the solid propellant production plant (UPG) facility in French Guiana, marking the end of an era for the European space industry. The Ariane 5 EAP has been an integral component of the Ariane 5 launch vehicle, providing crucial additional thrust during the first few minutes of a launch. The booster will fly on the final flight of Ariane 5, designated VA261.

The EAP has been used on Ariane 5 for more than two decades, and its retirement is part of a broader plan to modernize the Ariane launch vehicle family. The new Ariane 6 launcher, developed to replace both Ariane 5 and Soyuz ST launchers, features a new solid rocket motor called P120C. The P120C is a smaller and less powerful motor than the Ariane 5 EAP, and it will be used on Ariane 6, Vega-C and Vega-E rockets once Ariane 5 retires.

About the EAP

The EAP was developed by the French aerospace company, Snecma (now known as Safran), and the Italian aerospace company, Avio. It is a large solid rocket motor, consisting of a steel casing, a nozzle, and a solid fuel made of ammonium perchlorate composite. The motor provides an additional 7,500 kilonewtons of thrust during the first two minutes of an Ariane 5 launch, which is roughly 92% of the total thrust at liftoff.

The Ariane 5 EAP has been used on every single Ariane 5 launch, including some of the most significant missions in the history of the European space program. These missions include the launch of the Rosetta spacecraft, which studied a comet and its environment, and the deployment of the Herschel and Planck observatories, which studied the early universe and the cosmic microwave background radiation. The James Webb Space Telescope (JWST) was launched on Ariane 5 too.

A bittersweet end

The manufacturing of the last Ariane 5 EAP marks the end of an era, but it also signifies the beginning of a new one. The development of the P120C solid rocket motor represents a significant investment in the future of the European space industry and the Ariane family of rockets. The new booster will provide increased performance, reliability, and flexibility, which will be used on a wider range of launchers than the EAP ever was.

ArianeGroup, which is responsible for the development and production of Ariane launchers, has already begun the production of the P120C motor at its facility in French Guiana. The first Ariane 6 launch is scheduled for late 2023 and it will mark the beginning of a new chapter in the history of the European space industry.

In conclusion, the manufacturing of the last ever Ariane 5 EAP is a bittersweet moment for the European space industry and its followers. While it marks the end of a successful era, it also signifies the beginning of a new one.