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This paper presents thermal-vacuum test data obtained for the JEM MAXI loop heat pipe (LHP) with two separate radiators operating under transient regimes representative of those to be encountered during the flight. The Monitor of All-sky X-ray Image (MAXI) in the Japanese Experiment Module (JEM), on the International Space Station (ISS), is an X-ray camera with wide fields of view to monitor the universe. The LHP collects about 32 Watts of heat dissipated by the detector and thermoelectrics and transports it to two separate radiators, with orthogonal views to space. Propylene is used as a working fluid due to a wide useful operating temperature range from -60°C to +60°C needed for this program. The LHP utilizes two fluid flow regulators to control fluid flow in the two parallel condensers and is equipped with two startup heaters, and three shutdown heaters controlled by six thermostats.

The Advanced Land Observing Satellite “DAICHI” (ALOS) is the latest Japanese 4-ton class earth observing platform launched on January 24, 2006. The primary mission of DAICHI is obtaining enormous amount of data for global topographic maps and emergency disaster observation. It is equipped with three remote sensing instruments; the stereo mapping panchromatic imager, the multi-spectral radiometer and the L-band synthetic aperture radar. The thermal control of the DAICHI employed new technologies enabling highly accurate earth observation and gigabit per second mission data handling. A combination of passive and active control techniques stabilizes orbital temperature variation of the truss structure and a large optical bench for observing instruments within less than a couple of degree C. The bus structure is entirely made of low CTE and high thermal conductive pitch-based CFRP instead of conventional aluminum alloy.

Japanese X-ray astronomy satellite ASTRO-E2 named “SUZAKU“ was successfully launched on July 10, 2005. SUZAKU is the fifth Japanese X-ray astronomy satellite to observe X-ray coming from hot and active regions in the universe in collaboration with NASA GSFC, MIT and University of Wisconsin. “SUZAKU” has achieved the high sensitivity wide energy band X-ray spectroscopy than ever before. It is equipped with X -ray telescopes (XRT) and three kinds of focal plane instruments, X-Ray Imaging Spectrometer (XIS), X-Ray Spectrometer (XRS) and Hard X-Ray Detector (HXD). A radiation-cooling system, connected to XIS and HXD with heat pipes, is provided to cool them below −30 C and −20 C respectively. Furthermore, a side panel has a large cut out to expose XRS cryogenic Dewar for direct cooling. Flight temperatures indicate that the three sensors are kept below their cooling-requirement temperature.

Coating has been recently considered as having good potential for use in preventing in-cloud icing on the leading edge of the lifting surfaces of an aircraft in cold climates. In terms of wettability, a coat may exhibit hydrophobicity or hydrophilicity depending on its specific properties. The same applies to the ice adhesion strength, which may be either high or low. It is thus necessary to determine which type of anti-icing or de-icing coat would be appropriate for a particular application in order to fully utilize its specific properties. Notwithstanding, a coat is incapable of preventing ice accretion by itself, and a perfect icephobic coat is yet to be developed. Coating is also sometimes applied to the surfaces of electrical heaters and load-applying machines to enable them to function more effectively and use less energy. The coating used for an electric heater, for instance, should be hydrophobic because of the need for rapid removal of molten water from the surface.

Japanese Experiment Module (JEM) called KIBO is the first manned space structure in Japan. Among several high technologies of JEM development, achievement of the air ventilation (AV) under the micro gravity was challenging because the requirements were very difficult to meet. The verification test in the module level under the operation of the flight hardware had a serious problem by the natural convection owing to the heat generation by the flight hardware. The analysis had problems how to verify its own validity because the turbulent flow around diffuser exits in addition to the laminar flowfield where the velocity is extremely small. This paper describes the solution of these problems in the analytical and testing verification points of view. As a result, we found our analysis applied to the AV performance could provide the complicated flowfield in low velocity with the effects of turbulent flow as well as natural convection.

An icing process of a single supercooled-water droplet is focused in the present study. A stationary icing as well as an icing of a moving droplet gives us great insights into the development of an ice-prevention system for engineering purpose. For academic purpose, it gives experimental findings in a two-phase flow. To understand the icing process, we applied a luminescent imaging technique. It uses a temperature-sensitive luminophore and a temperature-insensitive luminophore to create the luminescent water. The luminescent outputs from these luminophores are simultaneously captured by a high-speed color camera. By simply taking a ratio, the temperature distribution can be extracted. In this paper, this imaging system is shown with its temperature characterization. An icing process of a stationary droplet is shown in this paper. Also, a current status of an icing process of a moving droplet is shown.

This paper experimentally and analytically evaluates the heat rejection/retention performance of a reversible thermal panel (RTP) which can autonomously change thermal performance depending on its own thermal conditions. The RTP is considered as a candidate methodology for thermal control of Venus mission, PLANET-C, in order to save survival heater power. An RTP prototype was tested and evaluated. An analytical thermal model of the RTP was also developed, and basic performances of the RTP were evaluated. Thermal performance of the RTP when applied to the longwave camera (LIR) of the PLANET-C was evaluated with an analytical thermal model as functions of fin deployment directions and rear surface properties of the RTP's fin. The analytical results showed that the RTP can save heater power in comparison to a conventional radiator.

A Reservoir Embedded Loop Heat Pipe (RELHP) has a liquid reservoir, located in the evaporator, to ease start-up of the LHP. The RELHP is used for heat transfer from the experimental heat load to a deployable radiator (DPR) on the Engineering Test Satellite-VIII (Kiku-8). This DPR is one of the experimental apparatus on the Kiku-8. The RELHP in the DPR has an evaporator, a condenser, transport lines to circulate a fluid and it utilizes the evaporation and condensation of the working fluid to transfer heat. The DPR on the Engineering Test Satellite-VIII (Kiku-8) was launched into a geo stationary orbit by a H-IIA rocket on Dec. 18, 2006. The DPR radiator was deployed successfully and the first start-up of the RELHP in an orbital environment was conducted smoothly. This paper describes the characteristics of the DPR and the RELHP on Kiku-8 in an orbital environment in the first year.