Hiroto HABU

© 2020 IEEE. In recent years, expectations for low-cost and high-frequency rocket launches for space exploration have increased. Solid fuel rockets are small, inexpensive, and easy to handle. However, in the production of solid fuel, the mixing process and the transportation process are separate batch processes, leading to an increase in maintenance costs and disposal costs. In addition, being a manual process, it is difficult to manufacture large amounts simultaneously in a safe method. The authors have developed a mixing and transportation device that simulates the movement of the intestinal tract by using an elastic duct and a low pneumatic drive. In addition, actual fuel production has been carried out in a mixing and transporting experiment using this device. The effectiveness of this device has been exhibited from the combustion test of the produced fuel. In this paper, we present a high-quality and efficient method of mixing and transporting solid propellant material. This is a mixing of solid and liquid achieved by peristaltic movement done in real-time by adjusting the mixing degree of the mixture inside the device. The degree of mixing is determined by the solid propellant's volume and viscosity change. Therefore, we first investigate whether the content volume can be detected when the rigid bodies with different volumes are inserted. Next, we focus on the change in the viscosity of the mixture that occurs during the mixing process. We also examine the viscosity of the contents when fluids having different viscosities are inserted.

© 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Low toxicity ionic liquid monopropellant thrusters, such as hydroxylammonium-nitrate-based and ammonium-dinitramide-based monopropellant thruster, have been continuously developed and researched as replacement for conventional hydrazine thrusters. In this study, for the attitude and orbit control thruster of spacecraft, a chemical plasma space propulsion with ammonium dinitramide based ionic liquid has been proposed. The ignition systems have been used the discharge plasma of arc or non-equilibrium, and the generation methods of discharge plasma have been researched for decomposition and combustion of ionic liquid monopropellant. This paper presents the results of open-cup firing tests with discharge plasma for an ionic liquid monopropellant. This liquid monopropellant is a eutectic mixture of ammonium dinitramide, monomethylamine nitrate, and urea. In addition, the effects of ambient pressure on the characteristics of electric and ignition were evaluated. As a result, the breakdown and ignition of the ionic liquid were confirmed under sea-level condition and vacuum condition. After breakdown and ignition, exhaust flame was observed from downstream of reaction system at sea-level condition. In a range of ambient pressure from 10 Pa to 30 Pa, the plasma plume of decomposition gas was observed. In addition, at the each condition, the pulse discharge of unsteady state was observed from discharge waveforms after breakdown of the ionic liquid.