In this report, we describe the characteristic of iso-truss structure, and also describe the application in the space engineering. First, we briefly summarize about iso-truss structure. Next, the finite element method of three-dimensional frame structure is summarized as the method of structural analysis. The iso-truss structure is formurated as frame structure. Deformation of the structure is analyzed by numerical computation. And a result is compared with a shell structure. Finally, we proposes application in the space engineering field of the iso-truss structure.

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A new modeling method is proposed for non-rigid satellites attitude control design. The method is based on a component mode synthesis combined with a simple coordinate transformation and rigid elements. In this modeling, the flexibility of the joint parts and the configuration changes can be managed by the control designers themselves.

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This paper studies the On-Off control for spacecraft by the reaction control system. For such a class of spacecrafts the controller design is not easy since the actuator has nonlinear properties. Viewing this, we propose an optimal design method of the On-Off controller in the sense of H_∞ norm. In the synthesis, the optimal controller is obtained by solving linear matrix inequalities reduced from the bounded real lemma. Then we evaluate its performance by a numerical simulation for a rigid spacecraft model.

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The institute of Space Technology and Aeronautics in JAXA has researched on the development of 50∿100kg-class small satellites as a means of space demonstration technology on newly-developed components and devices for practical satellites. The Micro LabSat satisfies the above needs and demands. The Micro LabSat 1 is a small satellite with the spin stabilized attitude control in normal mode and the three axis stabilized attitude control in experiment mode. It was launched in December in 2002,and all experiments completed successfully. At present, our group has been engaged in a research on the Micro LabSat 2 with the earth-oriented three axis stabilized control. This satellite installs 5 kg-class nano satellites. On the basis of the fruits on these above satellites, so called, space demonstration satellites have been planned as one of our series projects.

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CubeSat project has started primarily for an education purpose to improve student's skill of space engineering and project management. The CubeSat program at University of Tokyo, ISSL (Intelligent Space Systems Laboratory), has been started since 1999 and it's first nano satellite named "CubeSat-XI", developed by students, was successfully launched by a Russian rocket "ROCKOT" on June 30,2003. Since then, the satellite becomes operational and the students have been performing various experiments and demonstrations of its bus technologies and the onboard camera. This paper briefly reviews the systems description, the operation and the results achieved until present moment.

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Tokyo Institute of Technology (Tokyo Tech) group have developed a pico-sized satellite CubeSat of 10 cm cubic and less than 1 kg in weight : Tokyo Tech's "CUTE-I, " and this has been successfully launched on June 30,2003 by a Eurockot's rocket ROCKOT from Plesetsk cosmodrome in Russian Federation. CUTE-I is one of the smallest civilian satellites in the world, and CUTE-I has been designed, constructed, integrated, tested and operated by the University group. Thus, this means that "MY satellite" has been realized. The paper explains CUTE-I system, launch campaign in Russia and some operation results

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It is verified that when a relative velocity distribution to a wing is a negative gradient upwards, lift and drag decrease and become negative at a certain value of the velocity gradient. When a airplane is in tail-wind at landing, a relative velocity to a airplane has a negative gradient, under the influence of boundary layer near the ground. Possibility that this is a cause of overrun is stated.

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Slush hydrogen is a two-phase solid liquid cryogenic fluid consisting of solid hydrogen particles in liquid hydrogen, various applications for which are anticipated, including the fuel for reusable space shuttles, the coolant for cold neutron generation and for superconducting equipments, as well as the transport and storage of hydrogen as a clean energy source. This paper reports on the results of three slush hydrogen production methods obtained from the laboratory scale experiments, which are the spray method, the freeze-thaw method and the auger method. Since the auger method is expected for large quantity slush hydrogen production, which is a matter of significant concern for its utilization in the future, the results of its performance analysis are reported.

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In order to conduct in-orbit servicing using space robots, we propose and develop a function distributed reconfigurable arm system for robot satellites. The arm can make a rearrangement between its upper 3DOF part and lower 2DOF part. This reconfigurability makes it possible to perform various in-orbit services by changing its configuration. Technical issues of reconfiguration are including end-effector mechanism, communications subsystem and power subsystem. For extemal sensors to obtain relative position and attitude information between satellites in order to perform reconfiguration autonomously, we examine CCD camera and PSD. Outline of the arm system and a fundamental reconfiguration experiment are shown in the paper.

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This paper discusses on the control law for space manipulator. Space debris problem is significant for the future space development. It is desired for space manipulator to capture and retrieve large space debris such as disable satellite. Most disable satellites are spinning because controller is malfunction. Before capturing the satellite, the controller of manipulator satisfies that the end-effecter synchronizes the motion of disable satellite. The controller is also required to reduce energy consumption. Optimal periodic controller changes the attitude of manipulator to minimize the energy consumption after repeating the periodic motion. Stability and optimality of the controller is shown analytically.

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