The improved replication technique to fabricate ultra-light CFRP mirrors for space telescopes

The technology to manufacture main reflectors of satellite-mounted telescopes using CFRP (Carbon Fiber Reinforced Plastics) was studied. CFRP has high specific rigidity and zero thermal expansion which are required for space telescopes. However, the difficulty of high precision machining of CFRP and the fiber print-through appeared on the surface have prevented CFRP from achieving high accuracy and surface smoothness required for the mirrors. We studied the replica technology and process conditions in detail. The replica technology was improved not only to eliminate the fiber print-through on the CFRP surface, but also to achieve high shape accuracy of the mirrors. At the moment, shape accuracy of 0.6 mu m and surface roughness of 3 nm were obtained. The area density of the CFRP mirrors was lighter than one-fifth of the conventional mirrors made of zero expansion glass which are machined for mass reduction. The lightweight and thermally stable CFRP mirrors are expected for reflectors of large aperture, and will improve the resolution of space telescopes.

Automated summary

This study investigated the technology to manufacture main reflectors of satellite-mounted telescopes using Carbon Fiber Reinforced Plastics (CFRP). By improving the replica technology and process conditions, the fiber print-through issue on the CFRP surface was eliminated and high shape accuracy of the mirrors was achieved. The lightweight and thermally stable CFRP mirrors are expected to enhance the resolution of space telescopes.