Development of composite radio telescope reflectors

One of the keys to the success of the square kilometre array (SKA) radio telescope will be the development of cost effective collecting area. Development of construction techniques for composite reflectors is an active R&D focus at the National Research Council's Dominion Radio Astronomical Observatory (DRAO), near Penticton, Canada. Composite materials offer a range of benefits over traditional metal structures in the construction of large (10 m+ diameter) reflectors. The high specific modulus of composite materials results in the construction of lighter and stiffer reflectors and the low CTE of these materials yields thermally stable structures. New developments in composite manufacturing processes have the potential to make composites a cost effective alternative for reflector antennas. The team at DRAO constructed and tested its first 10 -m diameter prototype reflector, the Mk1, in 2007, a second prototype, Mk2, incorporating improvements in performance and manufacturability was completed in the fall of 2008. This paper presents a review of the Mk1 measurement results and the preliminary measurements of the Mk2.