School of Science, University of Tokyo
School of Science, University of Tokyo
Institute of Space and Astronautical Science (ISAS)
Communications Research Laboratory
Institute of Space and Astronautical Science (ISAS)
Institute of Space and Astronautical Science (ISAS)
Institute of Space and Astronautical Science (ISAS)
Institute of Space and Astronautical Science (ISAS)
Institute of Space and Astronautical Science (ISAS)
The dynamics of neutral atmosphere is closely coupled with the behavior of ionized gas and chemical process in the lower thermosphere-mesosphere region. The measurement of the neutral wind at the height region is important to study those processes. So far the neutral wind has been independently measured by a radar-tracking of foil chaffs: a micro rocket is needed for the wind measurement in addition to a main, big rocket which carries other scientific instruments. In order to conduct simultaneous wind and other measurements onboard a single rocket, we have developed two types of foil chaff ejection systems to be installed in a sounding rocket. We have tested two foil chaff ejection systems: 1) foil chaffs are accommodated in an airtight cylinder case whose sealing cap is removed with one atmospheric pressure, 2) foil chaffs are accommodated in the splitted cylinder, which is ejected by a spring. These two ejection systems were loaded on a sounding rocket S-310-29, which was launched on the 10th, January, 2000. About 20,000 pieces of foil chaff in total were successfully ejected during the downleg of the rocket, around the height of 100km, 341sec after the launch. The foil chaff were tracked in the height range of 95.0-88.5km by the primary radar and the velocity and direction of the neutral wind were obtained.