An Ultra-lightweight Large-scale Antenna Reflector Supported By Tendon Reinforced Structure.
- Paper number
IAC-07-C2.2.04
- Author
Mr. Satoshi Harada, NTT Access Network Service System Laboratories, Japan
- Coauthor
Mr. Kiyoshi Kobayashi, NTT Network Innovation Laboratories, Japan
- Coauthor
Mr. Kohei Ohata, Japan
- Coauthor
Mr. Hiroyuki Ohmine, Mitsubishi Electric Corporation, Japan
- Year
2007
- Abstract
Nippon Telegraph and Telephone Corporation (NTT) has been investigating mesh deployable antennas for S-band mobile communication satellites. To extend satellite communication markets, we must dramatically increase the performance of the communication satellites with suppressing costs. Our success scenario for the construction of an economical system is to implement 100 beams-class multi-beam satellite communication equipments with 20m scale large reflector on one or one-half ton class satellite bus system. This paper dealt with a lightweight and large-scale reflector for future mobile communication satellite systems. To achieve the cost effective system, it is important that an ultra light-weight large antenna reflector, whose aperture diameter is larger than 20m and whose areal density is less than 0.25 kg/m2. Target total mass is 130 kg including the boom structure and holding structure. To realize this new reflector antenna, we proposed a tendon reinforced structure, which had slender rib structures and tendons (cables) to reinforce the structure. In this design, tendon placements were arranged to suppress the lower mode deformation by compression buckling. In addition, the geodesic cable network system, which defines the reflector surface shape, is designed to reduce the shape distortion by taking account of the deformation of the support structure. From our previous research conducted, it was clarified that the tendon reinforced structure has higher stiffness and strength than the structure without tendons. This effect and the low sensitive cable network system allow using more slender members for the deployable reflector structure. This configuration leads to reduce the reflector weight effectively. Then, we prospects that the reflector weight become around half of conventional design. For more advanced precise investigation, a 5m scale-model is fabricated. This model is composed of a tendon reinforced support structure and a complicated cable network system. The cable network system, which defines the reflector shape, has the number of cables that correspond to the number of the larger reflector for S-band. Experiments are carried out to clarify the shape accuracy and characteristics of the proposed reflector configuration. From these result, we confirmed that large deployable mesh antenna reflectors, whose aperture is 20m and whose weight is around 130 kg, appear feasible.
- Abstract document