Aluminium optics are critical for advancing space applications, particularly in athermal telescope architectures that integrate such optics with aluminium structures. These architectures provide superior thermal management and improved optical performance in orbit. However, existing solutions, like nickel phosphorus (NiP)-coated aluminium mirrors, face challenges from thermal mismatch and bimetallic effects. Recent innovations brought by hypereutectic aluminum-silicon alloys, such as the AlSi40, with coefficient of thermal expansion that matches that of NiP, address some issues. However, these alloys introduce vulnerabilities related to the poor toughness of high-silicon alloys.

A key breakthrough could be driven by the development of polishing processes for aspheric and freeform optics on bare aluminium substrates. Direct polishing of aluminum alloys would allow producing optics without the need of a NiP coating, fully leveraging aluminum’s potential in athermal telescopes. This advancement, however, faces obstacles induced by second phases and high ductility of aluminum, raising the risk of optical imperfections.

A consortium comprising Media Lario, Leonardo, and Politecnico di Milano has been formed to address these challenges within the framework of an ESA funded project named "Direct Aluminium Freeform Polishing". Media Lario leads the consortium as the prime contractor, contributing expertise in mechanical design, advanced polishing technology, and optical metrology, backed by its heritage in aluminium polishing for the several ESA missions. Leonardo complements the team with its broad experience in optical system design, manufacturing, and specifications, primarily focusing on the design of the freeform breadboard. Finally, our department with Prof. Casati, Prof. Patriarca, and co-workers will bring recognized expertise in aluminium alloys, encompassing additive manufacturing, microstructure characterization, heat-treatment optimization, and structural integrity.