This paper deals with a fundamental approach for a two-phase fluid loop system, with emphasis specifically on the discussion of its most important section, i. e. the evaporator or cold plate. As a basis of the study, a mathematical model was introduced which represents a simplified thermal configuration of the cold plate section. And numerical investigation was conducted to examine its heat rejection capability with respect to several parameters which will affect to the thermo-fluid characters of this section, such as fluid mass flow rate, quality, temperature difference, tube dimensions of the cold plate, and others. Some qualitative features have been obtained, although mathematical formulations employed in the model are derived from those developed for terrestrial use with neglecting the gravity effect in the equations. One major finding in this study is that there exist critical limits of working condition of the cold plate, indicating the practical restrictions between the parameters outside of which no stable heat rejecting performance will be realized.
A generalized master slave manipulator system which was assumed to operate near and/or around the space station was developed. A standardized serial communication line was used between the master and the slave manipulator. The master manipulator was designed to be well self-balance for getting as same feelings as if it was operated under the zero-gravity condition. A force/torque reflecting bilateral control using the force-torque sensor settled at the wrist of the slave manipulator was adopted. A experiment under which the slave manipulator was in a vacuum chamber was performed and it could be operated within a restricted sight of cameras set up in the chamber with changing the coordinates according to camera views. The problems which would result from adopting a generalized master slave manipulator system were almost solved except the delay caused by the calculation time.
In prospect of its wide technological applications, shape memory material has been investigated from the mechanical and the metallurgical aspects. Actuators and manipulators of the material can be drastically scaled down and will be durable under severe circumstances such as in vacuum. The material will become one of the candidates for a solid shock absorber in the space structures due to its perfect thermal recovery. It is now relevant to know the dynamic response of the material as well as the static one. Dynamic compression test was carried out by using the split Hopkinson pressure bar method in the wide temperature range from 201K to 366K. The temperature and the strain rate effects on the stress-strain relations were clarified in connection with phase transformation. At high strain rates, endo- and extho-thermic process involved in phase transformation inevitably plays a predominant role during deformation, and characteristics of mechanical behaviors are well understood from this point of view.