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現在、宇宙航空研究開発機構/宇宙科学研究本部では新しい無重力実験装置BOV(Ba11oon-based Operation Vehicle)の開発を行っている。BOVは無重力実験部として球体状のカプセルを持ち、カプセルが空力外乱の影響を受けないように2重構造の機体となっている。この機体は30秒(可能であれば60秒)の無重力実験時間を実現するために高高度気球を用いて上空40kmまで上げられる。このような実験システムを実現することで、長時間の無重力実験がより良い無重力実験環境で実現される。BOVのシステムにおいて最も注目するべき特徴はその2重構造である。外部シェルとなる機体は無重力実験カプセルとの相対距離を計測し、カプセルと衝突しないようにガスジェットスラスタによって制御される。これにより、実験カプセルは理想的な自由落下が可能になる。この新しい無重力実験装置の開発は2004年から始まり、2006年においては1号機の飛翔実験が行われた。この実験においては高高度気球、通信・情報処理システム、制御システムまたその他のセンサや全体の実験システムの確認が行われ、無事に実験システムが動作することが確認された。そして、2007年の春には2度目の飛翔実験が行われ、本実験システムの目的である長時間の無重力実験の実現が検証された。本稿ではこの無重力実験装置の開発と2号機実験の報告を行う。, A new micro gravity experimental system called BOV (Balloon-based Operation Vehicle) is developed in ISAS/JAXA. BOV uses a free-fall capsule with double-shell structure to prevent influence of aerodynamic disturbance. Additionally, BOV is raised to 40 km by a high altitude balloon to extend micro gravity duration to 30 (or possibly 60) seconds. Thus we realize a medium duration micro gravity system with good micro gravity environment. In this system, the most characteristic point is double-shell structure. The inner shell can fall freely since the outer shell measures the relative position with laser displacement sensors and is controlled by gas-jet thrusters not to collide the inner shell. The BOV's project has run since 2004. The first flight to check the whole system was accomplished in 2006. The aim of the first flight was test of a high altitude balloon, communication and data handling system, control system, onboard electronics and operation. The second flight was also accomplished in spring 2007. The aim of the second flight is to verify the effectiveness of the proposed method and demonstrate the long duration micro gravity. This paper presents the development of BOV's system and reports the result of the second flight for the new micro gravity experimental system., 資料番号: AA0063718054

現在ISAS/JAXAでは気球を用いた微小重力実験装置の開発を進めている。この実験は、(1)高高度気球で高度40kmまで上昇させる、(2)実験機体を切り離す、(3)30-40秒間の自由落下を実現するものである。この実験において、落下機体は30秒程度落下したとき超音速になる。したがって、この実験機体は微小重力実験の他に簡易な超音速飛行試験を提供できると考えられる。実際に、空気吸い込み式エンジンを搭載しての実験も予定されている。この将来の実験において、エンジンの性能を測るために、十分な超音速飛行時間が必要です。そのため、高度40kmからの単純な落下では不十分であり、落下中機体を引き起こす必要がある。今回は、現行の機体で超音速飛行が実現できるかと、引き起こしによって超音速飛行時間を向上できるかを評価した幾つかのシミュレーション結果を示す。, The microgravity experimental system that uses the high altitude balloon is now developed in ISAS/JAXA. This experimental method is, (1) the high altitude balloon is raised to 40 km altitude, (2) the experimental system is separated, (3) a free fall for 30-40 seconds is achieved. In the experiment, the fall body enters a supersonic state when the free fall time exceeds about 30 seconds. Therefore, it can be expected that this fall body will offer a simple supersonic flight experiment besides the microgravity experiment. Actually, it is scheduled to equip the air inhalation type engine developing in the future. In this future experiment, an enough supersonic flight time is necessary to evaluate the performance of the engine. So it is thought that the nose of the body have to be put up since a simple fall from the altitude 40 km is insufficient. This paper evaluates whether a supersonic flight can be achieved in the present experimental system, and whether a supersonic time can be extended by putting the nose up. Some simulation results in several conditions are shown to verify the effectiveness of the putting the nose up of the experimental body., 資料番号: AA0063718055

ドラッグフリー技術に基づいた新しい自由落下カプセルを、2006年5月に高高度気球B200を用いて高度40kmから投下し、微小重力実験が行われた。今回の最初の試験飛行により、3陸大気球観測所の制御室とカプセルとの間での無線通信、ドラッグフリー制御、そして飛行シーケンスを分析するための基本的データを得ることに成功した。, The first microgravity experiment using a new free-fall capsule released from 40 km altitude was performed on May, 2006 based on a drag-free technique. The fundamental data for analyzing the drag-free control, the flight sequence, and the wireless communication between the capsule and a control room were successfully obtained in the first test flight., 資料番号: AA0063732002, レポート番号: JAXA-RR-07-009

現在、JAXAの提供するS-520型ロケットを使用した観測ロケットプロジェクトに、テープテザーを使用する実験を提案中である。提案している実験は、1つの工学的実験と2つの理学的実験である。工学的実験は、幅30[mm]のテープテザーを1[km]展開するというものである。高速でテープテザーを展開するため、これまでのテザーの展開方法とは異なる、折りたたみ展開方式という新しい方法でテープテザーの展開を検討している。本研究では、プロジェクトをモデル化した数値シミュレーションと、折りたたみ展開方式での各実験について説明する。実験は、主に繰り出し抵抗測定実験と高速展開実験の2つである。また、現在取り組んでいるシステム全体の設計についても述べる。, A sounding rocket project is proposed to exploit the utility of bare electro-dynamic tape tether in space. The project consists of one technological experiment and two scientific experiments. The technological experiment is the swift deployment of tape tether of 1,000 [m] in length, 30 [mm] in width and 0.05 [mm] in thickness. We have devised the foldaway deployment method in order to deploy tape tether at high speed with sufficient reliability. The characteristics of the foldaway deployment method and each experiment to confirm the performance of the deployment method is described. Experiments include mainly two procedures which are the experiment on measurement of deployment drag employed with the Tower Type Deployment Simulator and the High Speed Deployment Experiment employed with Water Rocket Model. The time history of the deployment velocity at the actual payload separation is designed with using the numerical simulation. The whole system in the project is also under synthesized and some experimental verification is addressed including the ejection system and braking scheme for the tape tether deployment., 資料番号: AA0063481050

飛行方向を制御可能なパラフォイルの横風に対する応答性および自然風下での操舵性能の定量的把握を目的として、スパン3mのパラフォイルを用いてスレッド試験・建物屋上からの投下実験を継続的に実施し、データの蓄積を図っている。飛行環境をより実際に近づけるには、より高い高度からの飛行が必須であり、繰り返し実験が可能なゴム気球を利用した実験方法を今回確立した。高度70mから切離し、地上からの手動誘導飛行を3回行い、最後の試験では、予め決定した目標点から3.2mの地点に着地した。, For the purpose of accumulating flight data with emphasis on the lateral-directional stability of a parafoil, the free-flight experiments of the parafoil with 3 m span were conducted from a small balloon filled with helium gas. The parafoil was released from the balloon at the height of 70 m, and it was guided towards the pre-determined target by the manual commands from the ground. In the last experiment, it was landed at the point where the distance from the target was 3.2 m., 資料番号: AA0063480053

資料番号: AA0049122181

For promoting the wide use of inexpensive zero-g facilities, a new device is developed based on the yoyo principle. The yoyo motion of a capsule enables to produce its successive rise and drop motion that create the reduced g environment inside the capsule. For the first step of its development, an indoor sized model was manufactured for the educational purposes. Its reduced g ranges the lunar and planetary surface g levels, worthy of its name Ez-Space. Further improvements are promising on its operational characteristics, such as the larger in its physical size of experiment volume and the higher g quality approaching to zero-g., 資料番号: AA0048095001

スパンが3mの小型パラフォイルを用い、着地直前にフレア操作を遠隔操作により施すことで着地衝撃がどのように変化するかを実験的に調査するため、高さ20mからの投下実験を行った。具体的には、ペイロード内に加速度計を搭載し、両方のコントロールラインを引く際の時間をパラメータとして、測定された加速度との関係を調べた。, In order to investigate the effect of a flare on the landing shock, a series of flight experiments were carried out using a small parafoil with a span of 3 m from a height of 20 m. In the tests, a flare was applied right before the touchdown by a wireless command. The decelerations at the impact were measured by the 3-axis accelerometers which were installed inside of the payload. The relationship between the timing of the flare and the measured decelerations was discussed herein., 資料番号: AA0047897026

本稿では、非ホロノミックな姿勢変更として知られている猫宙返り運動について考察を行った。はじめに、ひねり運動についてまとめ、猫宙返り(猫ひねり)運動は中立軸に垂直な2つの軸まわりのトルク入力による2入力3軸制御の運動とした。ここでは角運動量保存が非ホロノミック拘束となっている。次に、猫を2つの剛体円柱と柔軟な関節からなるモデルとし、回転運動中のコーニング効果の寄与を調べるための数値解析を行った。, In this paper, nonholonomic posture change is dealt with. In particular, the twist motion of a free-falling cat is analyzed. The twist motion is well known as 'Falling cat phenomenon', then it was researched by many researches. There are nonholonomic constraints in the 'Falling cat phenomenon' the same as free flying space robot systems. At first, classified was twist motion, and then the twist motion of a free falling cat is defined as nonholonomic posture change. Secondly, by modeling a cat to two rigid cylinders with flexible joint, contribution of the coning effect to the twist motion was calculated. As a result of this calculation, it is concluded that initial attitude differs contribution of the coning effect to the twist motion of a free-falling cat. In order to change internal attitude of a cat, internal torque is generated between upper body and lower body. And then the internal torque works in transverse plane. Because internal torque is orthogonal to twist axis of a cat, the cat turns around the twist axis. This way to input the orthogonal torque to twist axis is applied to 2-wheel satellite, spacecraft with flexible joint, or maybe gymnastics., 資料番号: AA0046652026

Gas bubble removal is one of the most difficult problems in space materials processing. In this study, the difference in surface tension of two immiscible liquids is utilized to remove gas bubbles from one phase to the other, where the total interfacial energy of the system spontaneously decreases, which change plays a role as a driving force for the reaction. Experimental results using Plateau tank and the free fall facility are introduced, which confirm the spontaneous migration of the gas bubbles., 資料番号: AA0045438054

The effects of short-term microgravity on the swimming behavior of Paramecium have been studied using a drop tower, which provides a transitional phase of low gravity before starting the free fall. The basic mechanism of the tower is what is known as Atwood's apparatus. In the tower, the initial fall of a drop capsule is decelerated by a counterweight connected with a steel wire to the holder of the capsule over a pair of pulleys. After this transitional phase of low gravity, the capsule was released by a mechanical trigger system to start a free fall as reported previously. The changes of the g-value during the fall were recorded using two sensors of different sensitivities (Crossbow, CXL25M1Z, 25 g full scale and CXL02F1Z, 2 g) and a PC card recorder (Teac, DR-C2). The swimming movements of paramecia were observed by a video camera and the video images were transmitted by wireless to a remote videocassette recorder. An experimental chamber containing approximately 200 Paramecium cells was turned from horizontal to upright immediately before the start of the fall. Considerable oscillations in g were observed especially just after the onset of the transient low gravity, which may be caused by vibration of the counterweight and the steel wire connected to the capsule holder. Some changes in parameters of the helical tracks, such as an increase in wavelength of some tracks, were observed after the start of the low gravity phase. Further investigation is necessary to identify the effects of low gravity at various levels. Many paramecia showed ciliary-reversal responses during the fall, some of which might have been induced by the vibration of the capsule. Reducing the mechanical oscillation of the system and using mutants of Paramecium lacking ciliary reversal responses may offer some advantages in further analyses., 資料番号: AA0045438010

Supervisor:宮田一乘, 知識科学研究科, 修士

資料番号: AA0063732000, レポート番号: JAXA-RR-07-009

The giant magnetostrictive materials (GMM) such as TbFe2, SmFe2 and Terfenol-D have been widely studied because of high magnetostrictions at room temperature. An improvement of the magnetostrictive properties may induce wider application fields of electric-mechanical energy conversion. In this study, magnetic properties of TbFe2 alloys solidified under microgravity (micro G) conditions obtained by drop tube systems were investigated. The magnetic characteristics of TbFe2 giant magnetostrictive alloy were found to be influenced by the solidification rate., 資料番号: AA0046917078

第二部デカルトの自然学と古典力学 : §I.デカルト自然学の形成 : 第一部で我々は中世科学からガリレオの「位置運動論」の形成に至る過程を検討し, 同時にガリレオにおける自然哲学の体系としての一貫性の欠如を確認した。……