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.

On February 3, 2018 at the JAXA Uchinoura Space Center, JAXA experimented SS-520 No. 5 launch with a 3U sized cube sat called TRICOM-1R aboard. After liftoff, flight of SS-520 No. 5 proceeded normally. Around 7 minutes 30 seconds into flight, TRICOM-1R separated and was inserted into its target orbit. And the launcher became the world's smallest class satellite launcher. SS-520 launch vehicle is one of sounding rockets operated in JAXA/ISAS, and originally two stage rocket. In this experiment, to make this vehicle put a satellite into orbit, the third stage motor is added. And this sounding rocket has four tail fins for spin stabilization, but usually don't have an attitude control system during the flight. But in this mission, it is needed to control its attitude to ignite second and third motor toward horizontal after first stage bum-out. The gas jet system is installed into between the first stage and the second stage of the vehicle as a unique active attitude control system. The gas jet system can control the spin axis direction and the spin rate of the vehicle during the coasting fight. Because of this constraint, the apogee altitude after the burn out of the first stage motor almost correspond with the perigee altitude of the elliptical orbit. In this mission, the sounding rocket-based Nano launcher is planned to put TRICOM-1R into the elliptical orbit. Its targeted apogee altitude is about 1,800 km and its perigee altitude is about 180 km. Because the perigee altitude is relatively low, the orbit life is very short. One of the mission requirements is to make the vehicle an orbit insertion with more than 30 days orbital lifetime. The vehicle error or the environment error deeply affect the achieved trajectory. These errors must be small enough to put TRICOM-1R into orbit. This paper discusses about the trajectory design on how to manage the sounding rocket into a satellite launching vehicle, the effect of the orbital distribution depending on the various errors, the flight safety analysis, and finally flight performance evaluation.

<p>We have been developing a peristaltic mixer simulating the intestines to realize safe and continuous solid propellant mixing and transport. In this report, we propose quantitative packing mixed transportation of mixed materials in order to avoid cleaning the inside of the device, to avoid mixing of air bubbles into the material, and to improve the quantitative control of mixed materials. Specifically, a mixing experiment was conducted with the mixture in a bag. Based on the experimental results, we believe that mixing is possible even if the material is packed.</p>

© 2018 IEEE. In recent years, because the development of space technology has been increasing for the purpose of improving the social infrastructure, the expansion of space transportation systems based on low-cost and high-frequency rockets is important. Solid propellants used in solid-fuel rockets have properties of the compactness, inexpensiveness, and easy-handling. However, solid propellants are highly viscous slurries and highly explosive. As there is no device capable of continuously and safely transporting solid propellant, the process of manufacturing solid propellant is a batch process. We focused on the movement of human intestines that knead and transport with a small force as part of the development process. In this report, we design a mechanism for the mixing process by using a peristaltic mixing transporting device for efficiency and by automating the equipment. Specifically, we conduct two experiments with samples using an adjusted fluid ratio: A comparison experiment on fluidity and a pressure response experiment. We investigate the possibility of automatic control and efficiency by using the factors of pressure and flow rate.

<p>In recent years, the demand for rocket launching has increased due to the development of space technology. However, using inexpensive rockets is not always possible. Although the cost of solid-propellant rockets is relatively reasonable, safely manufacturing a large amount of solid propellant is difficult, and the manufacturing process is disjointed. Therefore, to achieve safe and continues manufacturing of solid propellant, we have developed the peristaltic mixing conveyor with pneumatic artificial muscle. In Dec.2017, we succeed manufacturing of the over 1kg practical composition propellant by our system, and in Feb.2018, we succeed burning test of it on ground.</p>

Copyright © 2018 by the International Astronautical Federation (IAF). All rights reserved. This paper investigates the launch capability of the SS-520 as a CubeSat launch vehicle. The SS-520 was developed by JAXA originally as a two-stage, spin-stabilized, solid-propellant sounding rocket. With less than 2.6 tons in total mass and 10 meters in length, the SS-520-5 successfully launched a single 3U-sized CubeSat into orbit on February 3, 2018. The SS-520-5 obtained its capability as a CubeSat launch vehicle by installing a 3 rd stage solid motor in addition to the RCS between the 1st and 2nd stages. However, its launch capability was limited (in target altitudes of perigee and apogee at 180 km and 1800 km, respectively) due to its rocket system configuration. In order to pursue the SS-520's launch capability, two effective modifications from the SS-520-5 are proposed: thrust enhancement of the 1st stage motor and installation of an additional RCS between the 2nd and 3rd stages. Furthermore, the framework of launch capability analysis is established by a multi-objective genetic algorithm (MOGA), where its two objectives are selected as the altitudes of perigee and apogee. The problem maintains its simplicity through the selection of only eight design variables of the six acceleration directions and two coasting durations. The analysis reveals that the two proposed modifications to the SS-520-5 work effectively but differently. The 10% increase of the 1st stage enhancement is particularly effective when the target altitude of perigee is low (e.g., 200 km), whereas the installment of the additional RCS with 30 kg increases accessibility to a much higher altitude of perigee, even to circular orbit reaching altitudes of 550 km for a 1U-sized CubeSat and 280 km for a 6U-sized CubeSat. Each modified configuration with the 1st stage enhancement and additional RCS installment enables carrying a payload about twice as heavy as that of the SS-520-5. The application of both modifications would result in launch capability able to deliver a 10-kg payload. From a more general perspective, the results in this paper suggest that it is possible for a very small launch vehicle of the 3-ton class and 10 meters in length to deliver a 10-kg-class payload into low Earth orbit.

© 2016 Institute of Electrical and Electronics Engineers Inc.. All rights reserved. JAXA has successfully launched the SS-520 No.5 with micro-satellite 'TASUKI' on February 3rd 2018 at Kagoshima Space Center at Uchinoura in Japan. The base-line of the SS-520 sounding rocket is a two-stage rocket which has a capability for launching an 80kg payload to a maximum altitude of about 1000 km. and spun by 4 tails for attitude stability. Enhanced SS-520 No.5 is a three-stage rocket for the smallest-class launch system in the world, which has the orbit injection capability of a micro-satellite of a few kilograms by adding a high-performance third solid motor and advanced rhumb-line control system. Total length of the rocket is about 9.6 meters, the gross weight is 2.6 metric tons, and the reference diameter is 0.52 meters. The `TASUKI` has some experimental purposes for 'store & forward' communication on orbit and earth observation by some commercial cameras and others. The key points of this launch was to newly develop the rhumb-line control system, compact and high performance avionics, some lightweight structures, and the third motor made of CFRP. The rhumb-line control system established an attitude maneuver of about 70 degrees to inject the 'TASUKI' into the orbit of perigee altitude 180km and apogee altitude 2000km. This rhumb-line control system has some high performance functions. It has an angular momentum control function with high attitude maneuver rate, and the suppression function of nutation angle generated by the disturbance of RCS thruster injection during high spin rate of about 1.6Hz. We performed a Motion Table (M/T) Test 'Real-time Simulation Test' with flight models of the avionics for verification of the rhumb-line control design and the soft-wear in the loop test for verification of the flight soft-wear. An active nutation control (ANC) function is also equipped for the reduction of the residual nutation angle after the rhumb-line control. We show the outline of the rocket system and developments, especially the rhumb-line control system with the compact avionics system. Finally flight results are showed and we show one of the future enhanced ideas of SS-520 No.5 type launcher for 10 kilograms class satellite.