An analytical study of the dynamics of manned rotating space stations under various steady-state and transient excitation, such as docking impacts, attitude system torques, and crew motions, has been conducted. The basic equations of motion for the spinning station are developed and expressions simulating the applied disturbances are introduced. Two stability systems, a gyroscopic wobble damper and a proportional jet damper are represented mathematically, and the motion of the station under the external disturbances has been determined with and without the effects of these stability systems. Computer results for a toroidal example station are presented, and the effects of a variation in the moment of inertia distribution are discussed. A description of an experimental facility capable of simulating the excitation considered in the theoretical analysis and of determining and recording the resultant station lotion is also included. / M.S.

The present work addresses the development of a method for the calculation of Convective heat-transfer and surface temperatures on heat-shields of Aeroassisted Orbital Transfer Vehicles (AOTVs) in hypersonic flow regimes. Inviscid flowfield solutions are obtained about the aerobraking shield on the AOTVs using axisymmetric Euler's equations. The flowfield solutions are coupled with laminar and turbulent boundary-layer equations and the heat-shield material properties to obtain convective heating rates and heat-shield wall temperatures. A method for obtaining non-dimensionalized solution of convective heat-transfer rates is obtained. This non-dimensionalized solution can be used for calculating convective heat-transfer rates and wall temperatures for various freestream conditions encountered during the aerobraking maneuvers. Calculations are carried out for perfect gas and equilibrium air cases, and the effect of wall catalysis on convective heat-transfer is also incorporated. The results are in good agreement with available experimental and numerical results for AOTVs. / Master of Science

A battery charger design for the NASA Earth Observing System (EOS) Space Platform has been developed and tested. This thesis discusses the design of the battery charger power stage and its current and voltage control loops. The charger was designed to minimize the mass and to maximize the efficiency. In addition to restoring energy to the batteries, this charger regulates the spacecraft bus voltage during the transition between eclipse and sunlight. The battery charger design and analysis was facilitated by use of the model for the pulse-width-modulated (PWM) switch and the new continuous-time model for current-mode control. Analyses of the battery charger small-signal behavior are compared to hardware measurements to verify modeling accuracy. / Master of Science

The design of a new computer language, called the User Interface Language (UIL), is analyzed and evaluated by coding a representative procedure. UIL will provide the man-machine interface for command procedures on the Space Station FREEDOM. The UIL procedure written is modeled after an operational procedure used in the Space Shuttle program. This work provides a concrete test case to verify that UIL can be used to implement procedures for the Space Station. The object oriented approach taken with UIL is based on the successful application of these concepts for a variety of other software tools in operation today. Three major enhancements are proposed in this thesis: event handlers, data structures, and class/object creation capabilities. The addition of these capabilities changes the character of UIL from an object manipulation language to an object based language. The new capabilities, if adopted, will profoundly change the future of UIL.

空間站探索是世界熱點研究問題，空間站巨大因此往往在外太空在軌建造和組裝，因此需要由宇航員和機器人開展大量的艙外工作（ Extra-Vehicular Activities，EVAs）。目前，宇航員的艙外工作存在以下三個方面的問題：（1）宇航員在移動攀爬和任務操作相互衝突的問題， 宇航員在艙外工作時不能一邊沿著扶手攀爬，一邊搬運載荷；（2）當前的空間機器人工作空間有限，在空間站表面有許多地方無法達到開展艙體檢查等在軌服務；（3）當前的空間機器人在狹窄空間裡操作效率不高，不能很好地避開障礙物和做精細化靈巧操作。 / 本論文針對以上問題提出了2 個機器人系統，四腿行走機器人（ Four-legged Robot Walker, FLRW ） 和圓弧軌道機器人（Circular Rail Robot System , CRRS）。四腿行走機器人擅長多退的扶手攀爬和操作，攀爬和操作可同時開展。四腿行走機器人還有一個可旋轉頭部（可旋轉的視覺系統）來增強攀爬過程中的視覺範圍。圓弧軌道機器人通過移動機器人在圓弧軌道的運動能完全覆蓋空間站的所有工作空間，該系統是在太空應用的第一個弧形軌道系統，同時也有最小的轉彎半徑。 / 本論文對提出的2 個機器人系統的移動性進行了深入的研究，四腿機器人側重在雙臂攀爬的策略、攀爬步態，並開展了全艙攀爬的在軌任務模擬驗證。圓弧軌道機器人開展了艙體軌道系統、多艙體軌道切換器、移動基座平臺、移動平臺驅動和轉彎半徑的深入設計與分析，並且完成了移動軌道平臺的原型樣機試製驗證。 / 本論文對提出的2 個機器人系統的操作臂開展了非球形腕部掛接、冗餘操作臂奇異點辨識研究，提出了一種雅克比初等變換（MJET）演算法進行操作臂奇異分析，該演算法可以將冗餘機械臂的6x7 奇異矩陣轉化到3x4 的子矩陣，大大提高了運算效率。論文還開展了在多移動物體環境下的避障研究，提出了一種即時的多移動物體障礙回避（MMOA）演算法，該演算法採用超曲面函數描述障礙物的包絡，採用偽距離即時計算與移動障礙物距離，取得了控制精度和即時性的平衡。 / 本論文對提出的2 個機器人系統的操作臂開展了動力學建模和在軌裝配研究，採用拉格朗日建模方法對操作臂建模，並與商務軟體ADAMS 對比驗證建模準確度。同時，並運用阻抗控制演算法針對ORU 的在軌抓取、安裝和轉移等在軌任務的實現驗證。 / 最後論文進行了總結和後續工作展望。 / Space station exploration is a global hot research topic. The space stations are usually large in scale so that they have to be fabricated and assembled in space, which involves a large number of Extra-Vehicular Activities (EVAs) by astronauts and robots. There are three main problems of EVA mission. (1) Astronauts experience a conflict between climbing and manipulation during EVA missions, as they cannot carry payloads while handrail climbing. (2) Current space robots have workspace limitations and cannot reach the whole exterior of a space station, making it challenging to carry out inspection and servicing. (3) It is also difficult for robots to avoid obstacles and perform fine manipulation tasks in a compact workspace. / Two robotics systems, the Four-Legged Robot Walker (FLRW) and the Circular-Rail Robot System (CRRS), are proposed to address the above problems. The FLRW is good at handrail climbing as it has multiple, identical legs. It also has a rotatable vision system to enhance its field of view during climbing. The CRRS provides full coverage of the space station workspace, as it is a mobile robot that drives on a circular rail system around the space station. This system is the first design of robotic system with circular-rail in space and also has the smallest turning radius. / The mobility of both robots is addressed. The FLRW analysis focuses on the climbing strategy and climbing gait analysis. The circular rail system, rail switch, mobile platform, driving force and turning radius of CRRS are carefully designed and analyzed. A prototype of the CRRS mobile platform is implemented for verification. / The proposed manipulator is designed with redundant joint and non-spherical-wrists. A Modified Jacobian Elementary Transformation (MJET) approach is proposed to determine all of the singularity conditions. This approach has a singularity isolation feature to reduce the computational workload. A Multiple Moving Obstacle Avoidance (MMOA) approach is proposed for manipulator path planning in a compact workspace. A super-quadric surface function is used to describe the shape of an obstacle, and the pseudo-distance from the manipulator to the obstacle is measured and controlled in real time. This approach achieves a good balance between computational complexity and accuracy. / The proposed manipulator is modeled using the Lagrangian dynamics formulation and the dynamics of the proposed manipulator is verified with the commercial software ADAMS (Automatic Dynamic Analysis of Mechanical Systems). The mathematics model has similar output in ADAMS under a constant torque input and a sine torque input. The Orbital Replacement Unit (ORU) assembly task is implemented using impedance control. Both simulation and hardware tests are completed for verification, and the experimental results show that the controller is good for on-orbit servicing tasks. / The contributions of the thesis are summarized and future work is proposed. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Yongquan. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 131-148). / Abstracts also in Chinese.

The ever-increasing convergence of U.S. military and commercial space activities poses new challenges to the viability of the legal concepts that have traditionally governed the use of outer space, and particularly the military use of space, from the beginning of the space age. This paper will look at two examples of where the melding of U.S. military and commercial space activities necessitates a reexamination of the applicable legal theories. Part I will examine the concept of self-defense in outer space, by considering the legality of the use of conventional military force to defend against "cyber-attack" on its commercial space assets. Part II will examine the concept of the use of outer space for "peaceful purposes" under international law, by focusing on the permissibility of military use of the International Space Station. As private commercial entities increasingly take their place aside State actors in outer space, understanding the impact of space commercialization on the law governing military-related activities in outer space becomes more-and-more important to policymakers, military planners, legal scholars and space law practitioners alike.

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This research paper discusses the design evaluation and selection of a transmission system to be used in checking out the Spacelab high rate data system. The transmission systems evaluated are discussed, as well as the criteria utilized in selecting the final system. The installation of a fiber optics cable and the testing of this cable are discussed. The determination of the optimum location of the high rate data bit synchronizer and Viterbi decoder is presented. Utilization of this data to justify the installation of a shorter fiber optics system inside the O&C Building is presented.

A contract was awarded to the Virginia Power Electronics Center to compare two battery discharger topologies for use on the Earth Observing System. The following report is the result of the optimal design, build and test of Voltage-Fed, Push-Pull Autotransformer battery discharger topology. The main thrust of this document is to achieve an optimal efficiency. The list of available parts is restricted to only those that are approved. Derating guidelines restrict the choice of power stage semiconductors in a manner that degrades efficiency so efficiency gains are sought by optimization of the power stage magnetics. A second goal of the design is to achieve optimal small and large signal performance. / Master of Science

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