1994 年 60 巻 580 号 p. 4023-4031
The GEOTAIL spacecraft, designed and developed by the Institute of Space and Astronautical Science (ISAS) of Japan, was successfully launched by NASA's DELTA II rocket on July 24, 1992. The dual spinning satellite, equipped with two different kinds of deployable wire antenna systems, each having a pair of 50m wire antennas, will contribute to better appreciation of fundamental magnetosheric mechanisms. Due to a distinct trend towards larger space systems, deployment structures of many kinds, such as space stations, tether experiment modules, and deployment antenna configurations as well as extensible wire antennas, are supposed to play a key role in the future space infrastructure. Even at the recent stage of space activities, however, deployment of structures in space is still among the most difficult projects, showing several examples of failure and incompleteness due to technical and mechanical problems in past years. An emergency operation was in fact executed for the wire deployment of the GEOTAIL to finally obtain complete configurations. The problem is further accentuated by the fact that the dimensions of the wire antennas may lead to undesirable wire vibrations as well as satellite attitude perturbations through in-orbit events scheduled, such as antenna and mast deployment, spin-up and -down operations, and attitude and orbit maneuvers, resulting in distortion of the attitude control accuracy and the scientific observation environment. In the study, in-orbit operations exciting the wire vibrations are reviewed and some of the typical flight data of practical importance are analyzed to reveal effects of such operations on the system response.