Building and operating scaled spaceplane demonstrators is a key for rapid project progress, technology validation and risk reduction. POLARIS follows this approach with a series of five demonstrators of increasing size, mass and complexity. By the end of 2022, already three out of the five planned demonstrators were successfully flown.
The first demonstrator STELLA was used for initial validation of aerodynamic characteristics and controllability of the spaceplane configuration. The vehicle executed its first flight in 2020 at the airport of Rotenburg/Wümme. STELLA is not in service any more.
ALEDA features approximately twice the wing area of STELLA and executed its first flight in 10/2022. ALEDA is a low-cost risk-reduction platform, mainly used for testing and tuning of automated flight controllers and sensors. By the end of 2022, ALEDA had already executed 19 flights at two airports without any issues.
ATHENA was built under a contract awarded by the German Armed Forces (Bundeswehr) as part of the project “Rapid Deployable Reconnaissance System RDRS”. The vehicle successfully conducted its first flight in 11/2022 at the airport of Peenemünde. ATHENA is much heavier, more powerful and more sophisticated compared to the previous demonstrators. The vehicle features beyond visual line of sight (BVLOS) telemetry and semi-automated flight control systems, and is designed for the later integration of a liquid-fuel rocket engine. Due to its higher mass, performance and BVLOS capability, the vehicle was required to fulfil a comprehensive regulatory framework, including dedicated vehicle operation license, restricted airspace implementation, long-range radio/telemetry licenses, environmental assessment and a special insurance. For emergency cases, ATHENA is also equipped with a redundant flight termination system (FTS).
MIRA is a dedicated validation vehicle for in flight-demonstration and testing of linear aerospike rocket engines. Linear aerospikes form a novel class or rocket engines that offer large performance increases compared to conventional rocket engines. Flight-testing including engine in-flight ignition and operation will be conducted under a Bundeswehr/BAAINBw study contract awarded in April 2023. The first flight is scheduled for late 2023.
NOVA will be the final demonstrator before the spaceplane. The main purpose is the demonstration of safe and repeatable rocket-powered supersonic flight capability at high altitudes, while fulfilling the full regulatory framework required for airport-based operation. The first flight is planned for early 2024.