Next generation space telescopes, which are currently being developed in the US and Europe, require large-scale lightweight
reflectors with high specific strength, high specific stiffness, low CTE, and high thermal conductivity. To meet
budget constraints, they also require materials that produce surfaces suitable for polishing without expensive overcoatings.
HB-Cesic® - a European and Japanese trademark of ECM - is a Hybrid Carbon-Fiber Reinforced SiC composite
developed jointly by ECM and MELCO to meet these challenges. The material's mechanical performance, such as
stiffness, bending strength, and fracture toughness are significantly improved compared to the classic ECM Cesic®
material (type MF). Thermal expansion and thermal conductivity of HB-Cesic® at cryogenic temperatures are now
partly established; and excellent performance for large future space mirrors and structures are expected.
This paper will present the whole manufacturing process of such a space mirror starting from the raw material
preparation until the polishing of the optic including cryo testing .
The letters "HB" in HB-Cesic® stand for "hybrid" to indicate that the C/C raw material is composed of a mixture of
different types of chopped, short carbon-fibers.