著者
片山 雅之 外本 伸治 麻生 茂 平山 寛
出版者
一般社団法人 日本航空宇宙学会
雑誌
航空宇宙技術 (ISSN:18840477)
巻号頁・発行日
vol.19, pp.47-55, 2020 (Released:2020-03-14)
参考文献数
16

The effect of aerodynamic drag on loss of the velocity of a microsatellite on LEO is investigated and compared with the on-orbit data of two microsatellites, Hodoyoshi-1 of the University of Tokyo and QSAT-EOS of Kyushu University, which were launched in 2014. A new model, which includes the influence of the solar activities on atmospheric density, is introduced in this paper. The results obtained from the model suggest that the effect of solar activity on the atmospheric density has to be considered with the deviation of F10.7 parameter due to the number of sunspots. The model is applied to a microsatellite composed of a cubic main body and a deorbit sail to estimate its altitude change due to aerodynamic drag. The rotation of the satellite is taken into consideration.
著者
伊達 直輝 坂東 麻衣 外本 伸治
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.81, no.826, pp.14-00657-14-00657, 2015 (Released:2015-06-25)
参考文献数
16

As low-thrust propulsion technology becomes increasingly popular, orbital estimation for low-thrust spacecraft may become an area of increasing interest. More frequent use of low-thrust propulsion to place satellites in orbit gives more opportunities for collisions and radio frequency interference as these spacecraft travel slowly through altitude ranges. The purpose of this paper is to develop a method for estimation of the osculating orbital elements for low-thrust spacecraft. To overcome the instability of the estimation problem with low-thrust acceleration, we estimate the mean elements instead of osculating elements. By use of the averaging technique, Hudson and Scheeres proposed an analytical model of secular variations of orbital elements under thrust acceleration. The resulting averaged equation has a nice property in which only a finite number of Fourier coefficients of the thrust acceleration appear because of the orthogonality of the trigonometric function. Based on the nonlinear state equation representation for the extended state variables which include not only orbital elements but also unknown Fourier coefficients, mean orbital elements and thrust history are estimated from perturbed observation data of mean orbital elements. Then, the mapping from mean to osculating elements which is derived from the perturbation theory is used to estimate the osculating elements. The proposed method is demonstrated through numerical simulations.
著者
伊達 直輝 坂東 麻衣 外本 伸治
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.81, no.826, pp.14-00487-14-00487, 2015 (Released:2015-06-25)
参考文献数
15
被引用文献数
1 1

Space Situational Awareness (SSA) has been recognized to be important for safe space activities. As low-thrust propulsion technology becomes increasingly popular, SSA for low-thrust spacecraft may become an area of increasing interest. In this paper, we propose an orbital estimation method to predict the long-term evolution of spacecraft trajectory under unknown low-thrust acceleration. In particular, by the use of the perturbation theory and a nonlinear Kalman filter, long-term variations of orbital elements and thrust accelerations can be estimated from observation data of mean orbital elements. Performance of our method are evaluated for both controlled and uncontrolled orbits.