Toshio Sugimoto

Design Evaluation of a Large Deployable Mesh Reflector

The deployment force over the deployment resistance force must be considered in the deployment force design of deployable mesh ree ectors. Deployment tests are usually conducted on the ground using gravitational force compensation to evaluate the deployment force design. The design evaluations resulting from deployment tests using a test object with a diameter of 7 m are described. Twenty-four magnetically suspended sliders were also used to suspend the test object to reduce the frictional loss of horizontal motion and to compensate for gravitational force. The deployment force is designed as three times the mesh reaction force and is generated by helical coil springs. The complete deployment performance is cone rmed by three deployment tests. An increase in the deployment resistance force is verie ed through asynchronous deployment of the deployable structures and the gravitational force compensation error of the mesh surface. Surface accuracy tests and static load tests under the same cone gurations as the deployment test were conducted to cone rm that a large deployable mesh ree ector with a 1.0-mm-rms error surface and 0.13-Hz structural rigidity can be achieved.

Characteristics of large deployable mesh reflector antennas for future mobile communications satellites

Characteristics of Large Deployable Mesh Reflector Antennas for Future Mobile Communications Satellites Takashi Ebisui, Akio Iso, Temaki Orikasa, Toshio Sugimoto and Shin-ichi Sato* Space Communications Research Corporation SF,Hayakawa Tonakai Bldg.,2-12-5,Iwamoto-cho, Chiyoda-ku,Tokyo 101,Japan A large deployable antenna is essential for effective mobile communication satellites. This paper describes the key technologies needed for such an antenna, our development plan, and characteristics of various scale models. The electrical scale models of the mesh reflector antenna and the mechanical models of the deployable reflector have been constructed to aid in antenna design. Our ultimate goal is a deployable mesh reflector antenna with 30 m diameter. The measured performance of the scale models corresponds closely to the calculated performance. These results will be extremely useful for designing large deployable mesh reflector antennas for mobile communication satellites. characteristics of various scale models. The electrical scale models of the mesh reflector antenna and the mechanical models of the deployable reflector have been constructed to aid in designing the actual antenna. Our ultimate goal is a deployable mesh reflector antenna with 30 m diameter[2]. One of the electrical models is a 1/15 scale model with 2 m diameter and 12 GHz frequency. The other model is a 1/17.5 scale model with 1.7 m diameter and 14 GHz frequency. The partial deployable mechanical model is composed of the Hexa-Link Truss structure. The other mechanical model is the TETRUS (Tetra Trigonal Prism Truss) structure. Both of these partial deployable models have a diameter of 3 m. The experimental measurements and calculations of these electrical and mechanical models are also described.

Deployment Test System Using Magnetically Suspended Sliders for Large Space Structures.

Various test methods have previously been adopted to test large deployable space structures. However, traditional methods are not applicable to a precise evaluation of three-dimensional deployment characteristics with quasistatic deployment motions. This paper describes the design and performance of a deployment test system using magnetically suspended sliders. The sliders support the deployable structure vertically, and each of them moves freely with negligible friction under the horizontal surface of a ceiling plate. All the sliders control the tension of their vertical cables independently using the feedback signals of the tension sensor to compensate for the gravity of the deployable structure. The test system using magnetically suspended sliders enables maximum drag with a horizontal motion of less than 0.25N and tension control precision from a suspension cable of within 0.25N. The adequacy of this test system is confirmed by a deployment test using a 7m test model.

Characteristics of Scale Models of Large Deployable Mesh Reflector Antennas and Study on Space Verification Test Plan.

A large deployable antenna is essential for effective mobile communication satellites. This paper describes the characteristics of various scale models of the large deployable mesh reflector antennas and a study on space verification test plan using the scale models. Our ultimate goal is a deployable mesh reflector antenna with 30m diameter. Two electrical scale models of the mesh reflectors have been constructed to evaluate the electrical performance of a mesh reflector antenna. The mechanical models consist of two partial deployable models that were designed and constructed to help develop the deployable reflector with 30m diameter. One of the models is the Hexa-Link Truss structure, and the other model is the TETRUS structure. Diameter of these models are 3m. The experimental measurements and calculations of these electrical and mechanical models are also described.