Browsing by Author "Matsumoto, Kan"

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Development of an Engineering Model of the Re-Deployable Radiator for Deep Space Explorer
(51st International Conference on Environmental Systems, 2022-07-10) Sawada, Kenichiro; Akizuki, Yuki; Kinjo, Tomihiro; Ogawa, Hiroyuki; Miyabara, Takeshi; Okahashi, Takakazu; Toyota, Hiroyuki; Nishiyama, Kazutaka; Imamura, Hiroshi; Takashima, Takeshi; Miyamoto, Keiji; Matsumoto, Kan; Watanabe, Kazuki; Nagano, Hosei; Okudaira, Toshiaki
Future deep space explorers need a technology that can drastically reduce the power consumption of heaters to enter the outer planets with small spacecraft. We are developing the re-deployable radiator named a Reversible Thermal Panel (RTP), which is a device that autonomously deploys and stows the radiator in response to changes in the temperature of the heat source, stowing the radiator at low temperatures to achieve an insulated state, and deploying the radiator at high temperatures to maximize the amount of heat dissipation. In order to achieve this autonomous thermal control, shape memory alloys are used as actuators, and also use highly thermally conductive graphite sheets as fins to improve heat dissipation efficiency. Japan is developing a deep space demonstrator called DESTINY+ to demonstrate future exploration technologies. For the on-orbit demonstration using DESTINY+, we have been developing an RTP Engineering Model (EM) with a mass of about 1.2 kg and a heat dissipation capability of more than 100 W. In this presentation, we report on the design, fabrication, and testing of an RTP-EM.
On-orbit demonstration of Advanced Thermal Control Devices using JAXA Rapid Innovative payload demonstration SatellitE-2 (RAISE-2)
(50th International Conference on Environmental Systems, 2021-07-12) Nagai, Hiroki; Tanaka, Hiroto; Kajiyama, Satoshi; Mizutani, Takuji; Nagano, Hosei; Sawada, Kenichiro; Matsumoto, Kan
In recent years, advances in thermal control technology have become essential for deep space exploration to achieve exploration goals. For missions that explore an outer planet, the limited power resources available from solar panels must be used to maintain the temperature of the spacecraft. Therefore, there is an urgent need to develop lightweight thermal control technology that does not use power resources. ?We have conducted research and development of original thermal control devices such as flexible deployable radiators, thermal straps, self-excited oscillating heat pipes, and heat storage devices, and their effectiveness has been confirmed in ground tests, but there has been no opportunity for on-orbit technical demonstrations, and there has been no path to practical application. However, we were selected in 2018 to participate in the Innovative Satellite Technology Demonstration Program proposed by JAXA, and we have the opportunity to conduct on-orbit experiments with the RApid Innovative payload demonstration SatellitE-2 (RAISE-2) in 2021. However, we were selected in 2018 to participate in the Innovative Satellite Technology Demonstration Program proposed by JAXA, and we have the opportunity to conduct on-orbit experiments with the Innovative Satellite Technology Demonstration Satellite 2 in 2021. This program provides opportunities for private companies and universities to acquire and accumulate new knowledge using nano-satellites, to create future mission projects, and to conduct on-orbit demonstrations of key components and new element technologies for space systems.
Thermal Vacuum Testing of Advanced Thermal Control Devices for Flight Demonstration
(51st International Conference on Environmental Systems, 2022-07-10) Kajiyama, Satoshi; Mizutani, Takuji; Ishizaki, Takuya; Tomioka, Kota; Tanaka, Hiroto; Nagai, Hiroki; Matsumoto, Kan; Sawada, Kenichiro; Machida, Yoshihiro; Matsumoto, Kazuaki; Nagano, Hosei
In Japan, several unique thermal control technologies have been developed. However, there are no opportunity to demonstrate in orbit. Therefore, we have proposed to apply our thermal control devices named advanced thermal control devices (ATCD) to the Innovative Satellite Technology Demonstration Program conducted by JAXA, and accepted to apply to the Rapid Innovative payload demonstration SatellitE-2. In this paper, the test results of the thermal vacuum testing of ATCD are presented. ATCD consists of two types of flexible thermal straps: one is made of high-thermal-conductive material, and the other is made of a fluid-loop, and a re-deployable radiator. The conductive-type thermal-strap (CTS) is made of high-thermal-conductive graphite-sheets and aluminum blocks. The fluid-type thermal-strap (FTS) is made of a ultrathin loop-heat-pipe. The re-deployable radiator named reversible-thermal-panel (RTP) is made of high-thermal-conductive graphite-sheets as a flexible fin, and a shape-memory-alloy as a passive re-deployable actuator. As a result, it was confirmed that the thermal conductance between the two ends of CTS was 0.50-0.55 W/K. As for FTS, it was confirmed that it could operate even after recovering from the freezing condition of the working fluid, and that there was no leakage of the working fluid and no performance degradation under vacuum environment. As the heat load increased, the thermal conductance between the evaporator and condenser increased, and finally a thermal conductance value of 4.1 W/K (at 5 W heat load) was confirmed. For RTP, it was confirmed that the radiator fins were fully expanded to 130 when the SMA actuator reached 30 ? during heating. On the other hand, during cooling, the temperature of the SMA actuator dropped only to -15?, and the fins retracted only to 40 . Furthermore, the temperature hysteresis of the SMA actuator was estimated to be about 40? based on the experimental results.