German aerospace startup POLARIS Spaceplanes, headquartered in Bremen, has reached a significant milestone with the successful testing of a 3D printed Aerospike rocket engine. This achievement underscores the increasing relevance of 3D printing technologies in the aerospace sector. The prototype known as MIRA II, measuring five meters in length, completed both taxi and flight tests and features an innovative LOX\/Kerosene AS-1 engine created through additive manufacturing. The company anticipates that the prototype will be ready for scheduled flights by 2028.<\/p>\n
The MIRA II prototype was developed following the crash of the original MIRA demonstrator during a test flight in May 2024. Since then, POLARIS has made considerable advancements. The new prototype underwent a three-hour engine test on an airstrip and successfully completed unmanned flight tests above the Baltic Sea. In the latest test, the MIRA II took off from Peenem\u00fcnde airport powered by four turbojets. Upon ignition, the AS-1 engine produced a burn lasting three seconds, generating 900 newtons of thrust and an acceleration rate of 4 m\/s\u00b2.<\/p>\n
The Aerospike engine offers a more efficient alternative compared to conventional rocket engines that utilize bell-shaped nozzles. The MIRA II uses a dart-shaped nozzle which presents several advantages, primarily a reduction in weight due to its compact design. Moreover, the engine’s capability to adapt to varying altitudes and pressures ensures optimal performance and precise thrust adjustments.<\/p>\n
Despite its advantages, Aerospike engines face the challenge of intense heat generation during operation, which necessitates advanced cooling systems. To tackle this, POLARIS is leveraging additive manufacturing technologies from AM Global. The company plans ongoing optimizations for the Aerospike engine as part of a comprehensive flight testing initiative aimed at examining the operational viability of this innovative 3D printed technology.<\/p>\n