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Ariane 6 Upper Stage Testing Completes Successful Series of Tests
The upper stage of the Ariane 6 rocket has successfully completed its final set of tests at the European Space Agency’s (ESA) facilities in the Netherlands, paving the way for its upcoming launch as part of the rocket’s most powerful variant featuring four boosters. This advanced testing phase confirmed the readiness of the upper stage for its intended launch configuration.
Five distinct tests focused on evaluating the upper stage’s performance under varying acoustic levels. These assessments were conducted by the teams from ArianeGroup at the European Space Research and Technology Centre (ESTEC). The hot-fire test model utilized during these evaluations had previously been employed in a comprehensive hot-fire test campaign carried out from 2022 to 2024 at the German aerospace center, DLR, located in Lampoldshausen, Germany.
Rocket launches generate immense noise levels, which can be perceived even several kilometers away from the launch site. The upper stage model of Ariane 6 experienced these intense sound conditions at the Large European Acoustic Facility (LEAF)—the continent’s most potent sound-testing facility. This facility exposed the model to the extreme acoustic environment typical during an actual rocket launch.
Ariane 6’s Versatile Launch Configurations
The Ariane 6 rocket is designed with versatility in mind, allowing launches in multiple configurations that include either two or four boosters. This adaptability enables the rocket to tailor its thrust to suit the mission’s specifications and the weight of the satellites involved. The inaugural flight of Ariane 6, which successfully placed payloads into orbit in July 2024, utilized a two-booster configuration. Future launches employing the four-booster design, starting in 2025, will significantly enhance the thrust at liftoff, resulting in nearly double the initial power. However, this upgrade will also increase the acoustic pressure experienced by the upper stage by 60%.
Details of the Upper Stage Construction
A crucial component of the rocket, the upper stage—officially referred to as the Upper Propulsion Liquid Module (UPLM)—is situated approximately 34 meters above the rocket engines. It has been meticulously engineered to endure the rigorous conditions associated with a four-booster launch, which are expected to far exceed the noise levels observed during its maiden flight with two boosters. Preparatory testing for the UPLM included a week-long regimen that simulated the acoustic vibrations it will confront upon liftoff.
Comprised of over six meters in height, the UPLM represents the most substantial and heaviest element ever examined within the LEAF facility. For testing purposes, the module was held in an upright position, mimicking its orientation during an actual launch. While the propellant tanks that will be filled with liquid hydrogen and oxygen during flight were instead filled with water and glycerine for testing accuracy, 200 sensors monitored the structural responses to the intense acoustic waves.
To create realistic testing conditions, specialized black covers were installed to emulate the intertank structures and the acoustic shield provided by the rocket’s main stage at launch. Post-testing, images of the LEAF illustrate the facility’s robust design, featuring half-a-meter thick walls and doors intended to contain the intense noise generated during these evaluations.
Source
www.esa.int