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A loop heat pipe (LHP) is used as the heat transport device to reject heat from the Monitor of All-sky X-ray Image (MAXI). Since this LHP was designed exclusively for the MAXI system, it is different from conventional LHPs in configuration, a double-condenser design. We experimentally investigated the effects of the particular design of this LHP on the heat transfer performance by using the LHP Ground Test Unit (GTU) on the ground. The steady heating experiment was carried out to investigate the effective thermal conductance through the comparison with the prediction. When the two condensers were cooled at different temperatures under a steady heating condition, a quasi-periodic temperature oscillation was observed in the evaporator and accumulator area.

The Centrifuge Rotor (CR) system is a significant new development that will provide artificial gravity for gravitational experiments involving relatively large biological specimens such as small animals and plants. The Engineering Model (EM) test has been performed to evaluate the rotating performance and the vibration suppression system including active balancing system, vibration isolation mechanism, and active damping system. The EM test results show that the CR can create a stable artificial gravity environment. However, some CR technical issues have been clarified through the EM test such as the active balancing control, the active damping control, the vibration isolation mechanism, the structural reliability, and the air drag effect. The solution toward the Flight Model (FM) design will be discussed.

The Two-Phase Fluid Loop (TPFL) System is a heat transport system for future large spacecraft, using latent heat of coolant. TOSHIBA Co. has developed a ground test facility capable of dissipating a 5kw heat load and tested the components of that facility since 1988. As a next phase, static characteristics of the TPFL system are being studied. In this paper, static behaviors under heat load variation are presented as results of the experimental study and the numerical simulation. For the experimental study, the above-mentioned ground test facility was used. In this facility, heat is finally dissipated to the heat exchanger using brine as a heat sink. In order to determine static behaviors for an actual radiator heat rejection system used in orbit, numerical simulation was carried out. To confirm the analytical model used in the numerical simulation, the numerical result and the experimental result were compared.

Toshiba, under contract to NASDA is studying two-phase fluid loops (TPFL) as a thermal management system for future space platforms. For these fluid loops, two types of volumetric pumps, a trochoid gear pump and a scroll pump, are being developed, because volumetric pumps are, among others, less sensitive to cavitation. Recently, we designed and fabricated a scroll pump for our 5kW heat rejection TPFL in order to achieve a continuous and quiet operation of the system, which is required for space use. This scroll pump has four scroll vanes, two fixed and two orbiting ones, to reduce pulsation of flow. This paper reports the performance test results of a bread board model (BBM). The trochoid gear pump completed up to the BBM level, is also designed under the same requirements for comparison. Component tests of the pumps are carried out prior to installation into the TPFL. As expected, the scroll pump showed weaker vibration and lower noise.

The Centrifuge Rotor (CR) system, presented at the last ICES (Ohtomi et al., 1999) and scheduled to be launched in 2004, provides an artificial gravitational environment for biological specimens housed in habitats on the International Space Station (ISS). This paper presents the concept and investigation for realizing the micro-gravity (micro-g) performance, that is, the vibration suppression performance of the CR system which is the artificial gravity generator. The CR is a significant new development that will provide artificial gravity for gravitational experiments involving relatively large biological specimens such as small animals and plants. The CR rotates habitats located radially around the axis and generates centrifugal force, imposing artificial gravity of arbitrary magnitude up to 22.0 m/s2 (about 2.2 g) on the specimens housed in the habitats.