吉光 徹雄

第32回アストロダイナミクスシンポジウム (2022年7月25-26日. ハイブリッド開催（JAXA相模原キャンパス& オンライン)) The 32th Workshop on JAXA Astrodynamics and Flight Mechanics 2022 (July 25-26, 2022. Hybrid(in-person & online) Conference (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)) 資料番号: SA6000181030 レポート番号: ASTRO-2022-B004

大気球シンポジウム 平成28年度（2016年11月1-2日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000057016レポート番号: isas16-sbs-016

大気球シンポジウム 平成28年度（2016年11月1-2日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000057015レポート番号: isas16-sbs-015

大気球シンポジウム 平成27年度（2015年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000044003レポート番号: isas15-sbs-003

大気球シンポジウム 平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 18名資料番号: SA6000021014レポート番号: isas14-sbs-014

JAXA is planning to launch Hayabusa 2 in December 2014. Hayabusa 2 will be equipped with an asteroid exploration rover which is developed by the consortium of universities. A goal of the rover is establishment of the technology for locomotion on asteroid surface. In our previous work, we proposed a new moving mechanism called "Environment-Driven Torquer, EDT." The EDT is driven by environment temperature with bimetal. In other words, the EDT can move the rover without both battery and CPU. We have developed an engineering model with magnet latch. In this paper, performance evaluation of the EDT is executed by free-fall experiments in ZARM.

Asteroid probe Hayabusa 2 is developed by JAXA. Asteroid exploration rovers will be carried by Hayabusa 2. In our research project, we have developed an environmental-temperature-driven buckling actuator with a bimetal thin plate for a hopping mechanism of the rover. In this study, to characterize the hopping capability of the actuator, we conducted microgravity examination in ZARM drop tower. We fabricate a test rover for the microgravity examination with a rapid heating system for actuation in short free-fall time. Although reaction force from baseplate was incomplete in take-off, the rover hopped with a vertical velocity of 3.12 mm/s with 0.035 rad/s rotating rate.

Asteroids have some tips to know the origin of the solar system. In recent years, asteroid exploration by surface explorers has been studied actively. Conventional rovers can move under microgravity, but the rovers have not considered thermal control. In this paper, a new type of rover is proposed to move under microgravity and to control its temperature. The effectiveness of the proposed rover is investigated by simulations.

Japan has decided to launch the second sample return mission "Hayabusa-2" to the Near Earth asteroid 1999JU3 in 2014. The predecessor spacecraft "Hayabusa" made a great success when it returned to the Earth in June 2010 with a capsule containing some particles obtained around the S-type asteroid "Itokawa." The authors installed a tiny hopping rover called "MINERVA" into Hayabusa spacecraft. The rover was deployed at the vicinity of the asteroid in 2005, but failed to make a surface exploration since the human operator on the ground made a critical failure in deploying the rover. The second spacecraft also involves a plan to have a tiny rover system which will make a surface exploration over the 1km-sized asteroid. With the past experience in developing a rover, the authors are again working to install some rover packages to Hayabusa-2. The total concept is the same but this time multiple rovers are considered. Many of the aspects of the mother spacecraft come from the heritage of the previous explorer which was build using the technologies more than ten years ago. But the rover system is a completely brand-new one, based on the lessons learned from the previous rover system. Since the target asteroid parameters are different from the previous target, the rover design has to be made from the beginning. We also face to the another technically challenging matters arisen from the point of the distance from the Sun as well as the surface cruel temperature of low-albedo body. This paper describes the system configuration of the rover system currently designed and developed for the launch in 2014.

The authors are involved in the development of a tiny rover system onboard "Hayabusa-2" spacecraft which is scheduled to launch in 2014 for the Near Earth asteroid "1999JU3." The development of Hayabusa-2 started very urgently after its predecessor spacecraft "Hayabusa" made a self-sacrificing reentry into the Earth in 2010. The authors have a heritage how to develop a surface exploration rover through the experience on "MINERVA" rover in Hayabusa mission. But the rover system for Hayabusa-2 is a brand-new one since it is designed to fit the new target asteroid, of which surface environment and conditions are different from those of the previous one. The mobile system of the primary rover has the same strategy on its hopping movement as MINERVA, but is slightly different on the configuration of the actuators. This paper describes the mobile system of the primary rover onboard Hayabusa-2.