「はやぶさ」は，世界で初めて地球圏の月以外の天体において着陸と離陸および試料採取と回収にいたるシーケンスの実施に成功し，小惑星への往復飛行，着陸，サンプリング，サンプルリターンの一連の技術獲得を果たした．また各種近傍観測データならびに回収サンプルの分析により，小惑星の構造・組成・生成過程等について画期的な知見をもたらした．「はやぶさ」で得られた工学的，理学的知見は，「はやぶさ2」および　現在開発中のDESTINY＋，MMXに発展的に継承され，深宇宙小天体からのサンプルリターン探査技術面で我が国が世界のTOPを走り続けることを可能としている．

抄録全体を表示

The cathode-less electron cyclotron resonance ion engines propelled the Hayabusa asteroid explorer, launched in May 2003, which is focused on demonstrating the technology necessary for a sample return from an asteroid, using electric propulsion, optical navigation, material sampling in a zero gravity field, and direct re-entry from a heliocentric orbit. It rendezvoused with the asteroid Itokawa after a two-year deep space flight using the ion engines in 2005 and accomplished a round trip space mission between Earth and an asteroid in 2010. For the deep space odyssey between Earth and the asteroid, the ion engines served the total accumulated operational time 39637 hour･unit, the powered spaceflight in 25590 hours. Hayabusa and microwave discharge ion engines pioneered the space exploration and will bring us further deep space. This paper also report recent topics in space technology associated with the surface science.

抄録全体を表示

The chemical propulsion system of Hayabusa-2 consists of 12 bipropellant thrusters whose thrust is 20N. The communication with Hayabusa was lost due to the fuel leakage just after touchdown in 2005. Akatsuki failed to enter orbit around Venus in 2010. The chemical propulsion system of Hayabusa-2 took measure to prevent these accidents. It satisfied the requirements of continuous injection for SCI (Small Carry-on Impactor) operation. The short injection impulse was estimated using flight data. It was changed by the thruster temperature and the frequency of use. The approximation of the long injection impulse was improved using TCM (Trajectory Correction Maneuver) data and VIC (Velocity Increment Cut) test data. This paper presents development and outward operation of the chemical propulsion system of Hayabusa-2.

抄録全体を表示

小惑星探査機「はやぶさ」は2010年6月13日にオーストラリアに帰還し,試料カプセルを無事回収することに成功した.これに先立ち2010年4月以降,合計5回の軌道制御により,地球をフライバイする軌道からオーストラリアに帰還する軌道へと精密誘導を実施した.本報告は,誘導計画立案に新たに導入したパラメータを紹介し,このパラメータを用いた計画立案手法について解説する.

抄録全体を表示

This study discusses a pseudo periodic orbit that is a nearly periodic orbit around a small asteroid such as the Martian moon Deimos. By taking differences of orbital elements between the spacecraft and the asteroid as state variables, basic equations of the relative motion are derived based on Gauss' variational equations. From the basic equations, the initial state of the spacecraft to fly on the pseudo periodic orbit and its period are approximately derived. Furthermore, the stability of the pseudo periodic orbit is analytically examined from the state transition matrix of the linearized equation around the nominal orbit. Numerical studies are executed to verify the analytical results of the conditions and stability of the pseudo periodic orbit.

抄録全体を表示

科学衛星「はやぶさ」の成果は、地球帰還後に多くの人々に知られ、社会から賞賛されるようになった。その人気は何なのか、どのような人々が支えているのか、はやぶさ地球帰還1周年記念講演会の参加者から、その動向をさぐることにした。

抄録全体を表示

This paper deals with a free-flying space robot which grapples a target satellite based on a visual feedback control scheme. As the robot body is not fixed in an inertial space, manipulator motion causes changes in the view of the visual sensor. Therefore the closed loop system for the manipulator controller involves the visual data processing which normally takes long calculation time. We construct a control system which is not explicitly affected by the calculation time and analyze stability of the system. Analysis results show that a stable control system can be constructed in spite of the long calculation time, on condition that the manipulator trajectory which is not close to singular points is settled. Moreover we developed a zero gravity motion simulator which combined a computer simulation and servo mechanisms. An experimental space robot system is constructed and experiments to grapple a target are performed on the simulator. It is confirmed through the experiments that the free-flying space robot automatically grapples the target with the visual feedback control scheme proposed.

抄録全体を表示