Browsing by Author "Matsumoto, Satoshi"

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Bubble Effects on Electrolysis for Water Purification in Microgravity
(51st International Conference on Environmental Systems, 7/10/2022) Matsumoto, Satoshi; Yoshioka, Nasa; Saruwatari, Hideki; Matsumoto, Yukitaka; Ishiwata, Kazuya
The electrolysis under high pressure and high temperature is one of promising water purification processes of urine for future human space exploration missions. Fine gas bubbles are generated around the electrodes by electrolysis. It is considered that the buoyancy acting on the bubbles promotes departure from the electrode and transportation in electrolyte solution. In microgravity where buoyancy disappears, the bubble motion might be different from nominal gravity conditions and affect efficiency of oxidization of organic carbon including urine. In this paper, the behavior of gas bubble is modeled and the effect of gravity on electrolysis process for water purification of urine is estimated. The electrolysis voltage and current experimentally processed in microgravity are compared with the experiment on the terrestrial conditions and the stability and efficiency of electrolysis are discussed.
Development of Portable Gas Chromatograph Using Ball Surface Acoustic Wave Sensor for Measurement of Crewed Space Environment
(51st International Conference on Environmental Systems, 7/10/2022) Iwaya, Takamitsu; Akao, Shingo; Yamanaka, Kazushi; Okano, Tatsuhiro; Takeda, Nobuo; Tsukahara, Yusuke; Oizumi, Toru; Fukushi, Hideyuki; Sugawara, Maki; Tsuji, Toshihiro; Tanaka, Tomoki; Takeda, Akinobu; Shima, Asuka; Matsumoto, Satoshi; Sugahara, Haruna; Hoshino, Takeshi; Sakashita, Tetsuya
A gas chromatograph (GC) is effective as one of the methods for monitoring the atmosphere in a crewed space environment. However, the GC is generally large and difficult to carry. We have developed portable GC systems with a ball surface acoustic wave (SAW) sensor; ball SAW GC. The key features of the ball SAW GC are multiple roundtrips of SAW on a spherical element and a metal micro-electro-mechanical-systems (MEMS) column formed by etching and diffusion bonding of stainless-steel plates. In addition, using the feature of ball SAW sensor that can detect gases non-destructively, we have developed a forward flush method realizing fast analysis of multiple gases by combining two columns and two sensors. In this study, we developed a prototype ball SAW GC applied the forward flush method with the volume of 1 L and which has the same functions as a desktop GC such as a sampler, a preconcentrator, and a column heater. Using this GC, we succeeded in analyzing multiple hazardous gases assumed in the crewed space environment.
Development status in 2021 of JAXA CO2 removal system for closed ECLSS
(50th International Conference on Environmental Systems, 7/12/2021) Sakai, Yoko; Oka, Toshiharu; Matsumoto, Satoshi; Nakanoya, Sogo
The Japan Aerospace Exploration Agency (JAXA) has been developing a CO2 removal system for acquiring core life support technologies for future manned space missions. JAXA has also been engaged in development activities for a system (including adsorbent) capable of removing cabin ppCO2 under 2 mmHg from four crew members on missions to Mars. JAXA has already verified that CO2 from four persons can be removed using an adsorbent developed from a bread board model (BBM). This paper reports the development status of the CO2 removal system as of 2021.
Development Status of Oxygen Generation System and Sabatier System for future exploration missions
(50th International Conference on Environmental Systems, 7/12/2021) Yamazaki, Chiaki; Futamura, Shotaro; Toshiharu, Oka; Matsumoto, Satoshi; Shima, Asuka; Sakurai, Masato; Nakanoya, Sogo
JAXA has been working on the conceptual study of an Oxygen Generation System and Sabatier System for future space missions. The Oxygen Generation System employs a cathode- feed system that utilizes a special JAXA-developed membrane. The study confirmed that the system could provide a stable source of oxygen for two to six crew members. The Sabatier System has a CO2 conversion efficiency of 95.2% at a flow rate of 6.32 NL/min of H2 and 1.58 NL/min of CO2; the system uses a nickel-zirconia catalyst. This paper also reports the reaction efficiencies under different gas flow rates and mixing ratios of CO2 and H2, as well as the improvement of the Sabatier reactor.
FY2024 Development Status of DRCS: ISS Demonstration of JAXA’s CO2 Removal System
(2024 International Conference on Environmnetal Systems, 2024-07-21) Yamazaki, Chiaki; Hirai, Kentaro; Futamura, Shotaro; Shido, Yohei; Matsumoto, Satoshi; Otsuka, Koji; Saruwatari, Hideki; Nakagami, Hidetoshi; Nagase, Mutsumu; Kinoshita, Tomohiro; Yoshino, Naomi; Yogo, Katsunori
The Japan Aerospace Exploration Agency (JAXA) is developing a CO2 removal system to strengthen core life-support technologies for future crewed space missions. The ISS demonstrator of the CO2 removal system (DRCS) is being developed as one of the activities demonstrating Gateway's CO2 removal system (CDRS) and is scheduled to be launched in FY2024. This paper describes the features of the DRCS, the results of the performance tests of the DRCS Proto Flight Model, and the progress of the validation tests.
Investigation of Dissolved Air Effects on Subcooled Flow Boiling Heat Transfer for Boiling Two-Phase Flow Experiment onboard the ISS
(44th International Conference on Environmental Systems, 2014-07-13) Sawada, Kenichiro; Kurimoto, Takashi; Okamoto, Atsushi; Matsumoto, Satoshi; Asano, Hitoshi; Kawanami, Osamu; Suzuki, Koichi; Ohta, Haruhiko
Boiling is a very efficient mode of heat transfer due to phase change, whereas the gravity effects on the two-phase flow phenomena have not been clarified in detail. To clarify these effects, boiling two-phase flow experiments onboard the Japanese Experiment Module “KIBO” are proposed as an official JAXA project and this project concerns the effects of dissolved air on flow boiling heat transfer, which remain to be clarified when using an inner diameter 4mm tube. This research involved conducting subcooled flow boiling experiments using various different dissolved air concentrations in the Perfluorohexane (PFH) in order to clarify its effects on flow boiling heat transfer through a tube with an inner diameter of 4mm, the following parameters were calculated and discussed: excess temperature, boiling curve and condensing heat transfer. Consequently, the dissolved air was shown to affect boiling characteristics. In particular, dissolved air significantly affected the boiling curve in the low heat flux region, and the boiling curve was continuously decreased with increasing the effective heat flux for both G=100 and G=300 kg/m2s respectively. Also, dissolved air significantly affect the onset of boiling. These effects include decreasing the cluster radius required to form a nucleus. Furthermore, despite the different dissolved air concentrations, none of the difference among the boiling curves in the high heat flux region due to fully developed flow regime, where a boiling curve was calculated by the S.G. Kandlikar proposed correlation effectively matched the experimental results in the fluid-surface parameter Ffl=1.7 usage case.
JAXA CO2 removal system ISS demonstration (DRCS) development status
(51st International Conference on Environmental Systems, 7/10/2022) Hirai, Kentaro; Sakai, Yoko; Yamazaki, Chiaki; Futamura, Shotaro; Yada, Hironori; Matsumoto, Satoshi; Saruwatari, Hideki
The Japan Aerospace Exploration Agency (JAXA) has been developing a highly reliable air revitalization system with less resupply for future manned space missions. This paper describes current and planned development status focusing on CO2 removal system for ISS demonstration. JAXA considers to have ISS demonstration of CO2 removal system for 1-crew scale. Ground tests and evaluation of new CO2 adsorbent canister, the lifetime and off-gas characteristics of the developed amine-based adsorbents, design overview of flight model are reported.
Preliminary Study of Moisture Absorption and Desorption in CO2 Removal System
(2023 International Conference on Environmental Systems, 2023-07-16) Sakurai, Masato; Shima, Asuka; Hirai, Kentaro; Yamazaki, Chiaki; Futamura, Shotaro; Matsumoto, Satoshi; Saruwatari, Hideki
Removing CO₂ and conserving water efficiently in a spacecraft are crucial. Dehumidifying methods are necessary. This study examined the effects of heating temperature, air flow rate, humidity, and desorption time on absorption time. The ability of Zeolite and CSX-250 to absorb and desorb moisture was clarified by experiment. The experiments showed the potential of CSX-250 to maintain the dew point temperature needed for effective CO2 removal.
Recent development status of Oxygen Generation System for future exploration missions
(51st International Conference on Environmental Systems, 7/10/2022) Futamura, Shotaro; Yamazaki, Chiaki; Matsumoto, Satoshi; Shima, Asuka; Sakurai, Masato; Saruwatari, Hideki
Japan Aerospace Exploration Agency (JAXA) has been developing a highly reliable air revitalization system with a smaller supply for future manned space missions. In this paper, we report the results of long-term continuous operation of the Oxygen Generation System using a sub-scale water electrolysis cell with Nafion membranes or membranes being developed by JAXA. In this study, continuous operation up to 2000 hours was achieved and the characteristics of the two types of membranes were determined. In addition, data contributing to the lifetime of the water electrolysis cell, ion exchange resin, gas-liquid separator, and the hydrogen sensors in the oxygen line were obtained. This paper also presents the lessons learned for the entire system through long-term operation.
Technology Demonstration of New Water Recovery System onboard ISS
(2024 International Conference on Environmnetal Systems, 2024-07-21) Matsumoto, Satoshi; Akashi, Megumi; Shido, Yohei; Saruwatari, Hideki; Matsumoto, Yukitaka; Izawa, Shuhei; Ishiwata,Kazuya
Life support systems that support human activities even in future far and long-duration human space exploration need to be regenerative in order to minimize the supplies. JAXA is conducting research and development of next-generation water recovery systems to purify the waste water to drinkable water. Our system uses electrolysis under high temperature and high pressure, and electrodialysis to decompose organic carbon and deionize, unlike NASA's distillation and catalytic oxidation methods. The challenges of liquid handling under microgravity are profound, particularly in understanding the unique behavior of bubbles in space compared to the ground. We performed a technical demonstration on the ISS, assuming that water electrolysis exhibits gravity dependence due to bubble formation during the process. In the demonstration experiment, a sub-scale water treatment system was used to purify the artificially synthesis urine as raw water to be treated. At first, it was operated under the same parameters as those that had been previously verified on the ground. Next step, in order to confirm the effect of microgravity, data was obtained by changing the flow rate and electrolytic current. As a result, it was found that water electrolysis could be performed under microgravity conditions with almost the same performance as on the ground, and the flow rate thresholds that indicate microgravity effects were also obtained. In order to better understand the phenomenon, we modeled the bubble behavior and discussed the experimental results in conjunction with the analysis.
The FY2022 Development Status of CO2 Removal System for ISS Demonstration
(2023 International Conference on Environmental Systems, 2023-07-16) Yamazaki, Chiaki; Hirai, Kentaro; Futamura, Shotaro; Matsumoto, Satoshi; Saruwatari, Hideki; Yamamoto, Ayako; Nakagami, Hidetoshi; Nagase, Mutsumu; Kinoshita, Tomohiro; Yoshino, Naomi; Yogo, Katsunori
The Japan Aerospace Exploration Agency (JAXA) is developing a CO2 removal system to strengthen core life-support technologies for future crewed space missions. The ISS demonstrator of the CO2 removal system (DRCS) is being developed as one of the activities demonstrating Gateway's CO2 removal system (CDRS) and is scheduled to be launched in FY2023. This paper reports the results of the DRCS Bread Board Model test and the Proto Flight Model's development status.