Masatsugu Otsuki

第31回アストロダイナミクスシンポジウム (2021年7月26-27日. オンライン開催)著者人数: 14名資料番号: SA6000167077レポート番号: ASTRO-2021-C024 The 31th Workshop on JAXA Astrodynamics and Flight Mechanics 2021 (July 26-27, 2021. Online Meeting)

The 31th Workshop on JAXA Astrodynamics and Flight Mechanics 2021 (July 26-27, 2021. Online Meeting)

<title>Abstract</title> The Martian Moons eXploration (MMX) mission will study the Martian moons Phobos and Deimos, Mars, and their environments. The mission scenario includes both landing on the surface of Phobos to collect samples and deploying a small rover for in-situ observations. Engineering safeties and scientific planning for these operations require appropriate evaluations of the surface environment of Phobos. Thus, the mission team organized the Landing Operation Working Team (LOWT) and Surface Science and Geology Sub-Science Team (SSG-SST), whose view of the Phobos environment is summarized in this paper. While orbital and large-scale characteristics of Phobos are relatively well known, characteristics of the surface regolith, including the particle size-distributions, the packing density, and the mechanical properties, are difficult to constrain. Therefore, we developed several types of simulated soil materials (simulant), such as UTPS-TB (University of Tokyo Phobos Simulant, Tagish-lake based), UTPS-IB (Impact-hypothesis based), and UTPS-S (Simpler version) for engineering and scientific evaluation experiments.

令和元年度宇宙科学に関する室内実験シンポジウムは、新型コロナウイルスの感染拡大防止のため開催中止。すべて書面発表になりました。資料番号: SA6000149028レポート番号: 28

The 29th Workshop on JAXA Astrodynamics and Flight Mechanics 2019 (July 22-23, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

平成30年度宇宙科学に関する室内実験シンポジウム (2019年2月28日-3月1日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県資料番号: SA6000139027

This paper presents the current development status of the optional payload named Lunar Excursion Vehicle (LEV) for the Japanese future Lunar landing mission SLIM. The deployable exploration system LEV is released from the lander at the few meters above the Lunar surface after the lander's terminal deceleration is finished. LEV consists of two probes that will move and observe around the landing site autonomously. They also help acquire the evidence of SLIM landing by taking pictures of the final status of the lander.

The world's smallest moon lander (OMOTENASHI) will be launched by NASA's space launch system. The lander impacts to the moon at 100km/h. The landing impact is absorbed by crushable materials and an airbag consisted of an external cover and an air chamber made by polyimide films. However, the coexistence of tough glued strength and lightweight will not be expected. Meanwhile, welding technique for polyimide films has been proposed which can be fabricated stronger and lighter than the glued films. In this paper, the development of the air chamber fabricated by using the welding technique for polyimide films is shown.

DESTINY+ is a flyby space mission for the asteroid named Phaethon and will be launched in 2022. Camera system in Flyby space mission has been conventionally controlled by a PD controller. However, PD controller cannot generally consider constraints. A flyby mission requires a robust control for constraints in traversing at high-speed. This paper proposes a control scheme based on Model predictive Control for a flyby mission with robustness for constraints of input and angular velocity. The simulation study shows that Model predictive Control is effective for robustness in a flyby mission.

When the lander carries a large amount of fuel, the landing on a celestial body becomes difficult and dangerous due to sloshing of fuel. Sloshing of fuel causes turbulence of attitude and overturning of the lander. In order to design a landing gear and attitude control system, landing simulation with a sloshing will be required. The mechanical sloshing model that takes the place of experiment and computational fluid dynamics is required for the landing simulator. This paper describes the modelling of mechanical concentrated-constant sloshing models for a landing simulator and the result of numerical simulations of landing on a small body celestial bodies.

Understanding the interaction between granular materials on surface of a small body and a spacecraft is the key issue to design equipments of the spacecraft utilized in a future planetary exploration. Aiming to realize a safe long-term stay on the small body, this paper presents the experimental results that acquired the basic data about the interaction through the drop tower test.