Structural Characteristics of an Ultra-light Large Antenna Reflector onboard Communication Satellites

摘要

We have proposed an ultra-light reflector antenna whose aperture diameter is larger than 20m and whose weight is less than 80kg. Our target is an areal density of 0.25 kg/m~2 or less. To realize this new reflector antenna, we propose a geodesic cable network system supported by a tendon-reinforced structure. To confirm the feasibility of this concept, we gave the cable structure and the supporting structure detailed analytical assessment. The analytical results showed the reflector structure has sufficient margin (surface accuracy) against in-orbit disturbances. Furthermore, we evaluate the analysis results by testing a scale model of the supporting structure. The scale model, which is around 3 m in diameter, consists of spoke-wise arranged deployable frame structures, tendon wires, and surface cables. Static load responses were measured by using strain gages and load cells. Deformation modes were also measured by a videometory system. We can conclude that the tendon-reinforced deployable frame structure can support four times the tension possible with the bare structure, and that the analytical results show good agreement with the experimental results by considering the initial imperfection of the scale model.