Yukihito Kitazawa

Effective Search Strategy Applicable for Breakup Fragments in the Geostationary Region

This paper proposes to apply the space debris modeling techniques to devise an effective search strategy applicable for breakup fragments in the geostationary region. The space debris modeling techniques describe debris generation and orbit propagation to effectively conduct predictive analyses of space objects that include characterizing, tracking, and predicting the behavior of individual and groups of space objects. Therefore, the techniques can predict population of debris from a specific breakup event. The population prediction specifies effectively when, where, and how optical measurements using ground-based telescopes should be conducted. The space debris modeling techniques can also predict motion of debris in successive images taken with ground-based telescopes. The motion prediction specifies effectively and precisely how successive images of objects in the geostationary region should be processed. This paper also validates the proposed search strategy through actual observations, targeting the ...

Use of elemental materials for the creation of an in-situ space dust impacts detector

This research focuses on space dust ranging from 100?m to 1mm. Space dust is mainly due to secondary space debris, which is called ejecta. The objective was to create an inexpensive space dust impacts detector using elemental materials. The detector is a glass/epoxy laminate printed circuit board with an area of 81cm2 for a weight of 30g. The detector can estimate the number of impacts and can give an approximation of the space dust size. The detector will be mounted on Horyu II that will operate in polar orbit for one year. In this article the authors report: a) the production of ejecta, b) the ejecta experiments on solar array coupon, aluminium honeycomb and CFRP/aluminium honeycomb, c) the detectors working principle and d) the estimations of the minimum detectable size of debris and collision probability. The ejecta experiments demonstrated that the ejectas mass is 7 to 46 times higher than the projectiles mass. For space dust in the range 100?m ? 600?m in diameter, the collision probability was calculated to be 16.5 percent. The detectors capabilities to detect broken lines and to transmit the data to the on-board computer were also demonstrated. This in-situ space dust impacts detector is thus a very promising research area for its lightness, low cost and its ability to provide immediate data on space dust population.