@techreport{oai:jaxa.repo.nii.ac.jp:00039707,
 author = {歌島, 昌由 and Utashima, Masayoshi},
 month = {Mar},
 note = {本誌は、軌道半径が1.5-3AUで半径が100km以下の小惑星を高精度に全球観測することを目的した小惑星周囲軌道の第1次の研究をまとめたものである。まず、小惑星周回軌道に輻射圧のみが摂動源として作用する場合に特徴的な凍結軌道の適用範囲を調査し、2種類の凍結軌道の内、公転面内軌道は20-50km程度の小惑星に対して適用可能であり、solar plane-of-sky軌道は2,3km以下の半径の小惑星に対して適用可能で有ることを示した。また、小惑星の偏平による軌道の変化を燃料を用いて修正するためには、一年当たり約100m/sの増速を要することを示した。次に全地球観測に有望な、偏平の影響を受けない極軌道の検討を行ない、極軌道の保持の為には一年間当たりの増速量が100m/s以下で良く、観測の面、燃料の面、保持運用の面で有利であることを示した。さらに、輻射圧と偏平による極軌道の平均要素の変化率を積分し、極軌道の保持を検討し次の結論を得た。(1)半径2-3km以下の小惑星ではsolar plane-of-sky凍結軌道を採用する。イメージャーの分解能はcm-10cmのオーダーとなる。(2)それ以上の半径の小惑星では極軌道を採用する。イメージャーの分解能は10cm-1mのオーダーとなる。, The first step results of the study on the orbits of 1.5-3 AU orbit radii around asteroids with maximum radii below 100 km performed aiming at the global observation of the asteroids are reviewed in this issue. Firstly, the frozen orbit, which can be realized in case that the solar radiation pressure alone is the perturbation, was studied and found that, among the two kinds of the frozen orbits, the orbit in the orbital plane of the asteroid is feasible for the asteroid with a radius between 20-50 km and the solar-plane-sky orbit is feasible for the asteroid with a radius below 2-3 km. It was also found that the increase in the velocity of about 100 m/s during one year is necessary to maintain the orbit by canceling the orbital change due to the oblateness by maneuvers. Secondly, the polar orbit which is adequate for the global observation of asteroids and it is not affected by the oblateness was studied and found that the increase in the velocity needed during one year is less than 1 m/s and the polar orbit is advantageous observation, fuel cost and operation. Taking into account of the result of study on the polar orbit maintenance by the numerical integration of the variation rate of the averaged orbital element, it was concluded as follows: (1) for asteroids whose radii are less than 2 or 3 km, the solar plane-of-sky frozen orbit is the first candidate. The expected resolution is in the order of cm-10 cm; and (2) for asteroids whose radii are larger than 2 or 3 km, the polar orbit is the first candidate. The expected resolution is in the order of 10 cm-1 m., 資料番号: AA0000269000, レポート番号: NASDA-TMR-960002},
 title = {小惑星周回軌道の研究},
 year = {1996}
}