矢野 創

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.

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.

国際アストロバイオロジーワークショップ2013（第6回日本アストロバイオロジーネットワーク年次研究会）（2013年11月28日-30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: 16名資料番号: SA6000008024

国際アストロバイオロジーワークショップ2013（第6回日本アストロバイオロジーネットワーク年次研究会）（2013年11月28日-30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: SA6000008045

The Memorandum of Understanding signed between the Japanese Aerospace Exploration Agency (JAXA) and the German Aerospace Centre (DLR) during the 63rd International Astronautical Congress (IAC) in Naples, paves the way for the Mobile Asteroid Surface Scout (MASCOT) participation in JAXAs Hayabusa-II mission. Like its famous predecessor, Hayabusa-II is foreseen to study and return samples from a Near-Earth Asteroid. In contrast to the previous mission, Hayabusa-II will also include a small lander package being developed by DLR and the Centre National d'Etudes Spatiales (CNES): the aforementioned MASCOT. Scheduled for a launch in 2014, Hayabusas-II journey will take 4 years until it will arrive at 1999JU3, a C-type asteroid. Following the initial remote sensing operations, MASCOT will be released to the surface and perform its science operations at its first location. Once this is complete, MASCOT will be able to 'hop' from one measurement site to the next. The payload suite will comprise a near-infrared microscope (MicrOmega, IAS Paris), a camera (CAM, DLR Berlin), a radiometer (MARA, DLR Berlin) and a magnetometer (MAG, TU Braunschweig). Realizing MASCOTs mission is difficult due to the strict mission requirements, the harsh landing environment and a short development time for a piggyback deep space mission. Aiming for high performance and reliability requires creative design solutions and novel developments in order to meet all challenges and to stay inside the mass limit of 11 kg. The status of MASCOT up to end of Phase B was presented at the 63rd IAC. With a flight model delivery scheduled for March 2014, the mission is now in the final stage of development and testing. The results of these tests have shown the strict limits of the structure and thermal design, and highlighted the risk in such a short project development. Lessons have also been learned regarding margin policy for such small spacecraft. Despite these challenges, the project is on-track, with all delivery milestones expected to be met. These last few months will serve to verify all of the design assumptions, before the launch in late 2014.

The JAXA Hayabusa-II mission is the follow-up to the original Hayabusa mission launched in 2003 \ which succeeded in returning the first dust particles from a near-Earth asteroid to Earth. JAXA intends to launch Hayabusa-II in 2014 for similar measurements of the asteroid 1999 JU3, a C-type asteroid, and invited the German Aerospace Centre (DLR) to contribute a small lander package to the mission. Based on this invitation, DLR is developing the Mobile Asteroid Surface Scout (MASCOT) to complement the main spacecraft's scientific objectives, with the Centre National d'Etudes Spatiales (CNES) providing payload and subsystem support. MASCOT will provide in-situ surface science and allow investigation of up to three sites on the asteroid surface. A short on-asteroid lifetime of two complete asteroid rotations (-16 hours) will provide measurements under different illuminations and thermal conditions, with Hayabusa-II being used to transmit all of the scientific data back to Earth. The harsh landing environment and strict mission requirements lead to some difficult design challenges. An innovative "hopping" mechanism will allow MASCOT to leap across the asteroid surface in bounds of up to 220m, albeit robustness of this concept must first be proven in a comprehensive suite of simulations and tests. Mass, limited to 10 kg, is critical: savings via the use of a carbon-fibre main structure and simplified subsystems allows the carriage of four scientific payloads, namely a multispectral wide angle camera, a radiometer, a magnetometer and an IR microscope. Thermal control is a challenge given the contrasting requirements of deep-space cruise and on- surface operation. Available energy also puts a strict limit on operations and restricts the lifetime of the mission. Copyright © (2012) by the International Astronautical Federation.

Japan Aerospace Exploration Agency (JAXA) plans to launch the small asteroid explorer "HAYABUSA2" in 2014, following the HAYABUSA mission. By improving the HAYABUSA probe, we are planning to visit the small asteroid "1999JU3", and aiming sample-return from an asteroid of different type from Itokawa. The 1999JU3 is a C- Type asteroid, considered to contain more organic or hydrated materials than S-type asteroids like ITOKAWA. The basic configuration of the spacecraft is mainly the same as HAYABUSA, with several minor modifications. The spectroscopic equipment and sampling system will be improved to be more suitable to C-type asteroids, because the surface of C-type asteroids is expected to differ from that of S-type ones. We will report the details of the sampling system of HAYABUSA2, and introduce our developing status of the sampling system. Copyright © (2012) by the International Astronautical Federation.

The Japanese asteroid explorer HAYABUSA launched in 2003 arrived at its target asteroid ITOKAWA in September, 2005. HAYABUSA has made amount of scientific discoveries and technological achievements during its stay at ITOKAWA and it came back to the Earth on June 13, 2010. Under this situation, the next asteroid exploration mission started. The spacecraft is called HAYABUSA-2. Although its design basically follows HAYABUSA, some new components are planned to be equipped in HAYABUSA-2 mission. A small carry-on impactor is one of the new challenges that were not seen with HAYABUSA. One of the most important scientific objectives of HAYABUSA-2 is to investigate chemical and physical properties of the internal materials and the internal structures in order to understand the formation history of small bodies. In order to achieve this objective, the impactor is required to remove the surface regolith and create an artificial crater on the surface of the asteroid. Ulis paper presents the overview of our small carry-on impactor system and impact operation of HAYABUSA-2 mission. And how to improve this impactor when it is applied to another small body exploration mission is also presented in this paper. Copyright ©2011 by the International Astronautical Federation. All rights reserved.

The minorbody explorer called "HAYABUSA" conducted sampling mission on the minorbody "ITOKAWA", and now it is planning to develop next minorbody explorers. The LSS, laboratory for space systems at the Tokyo Institute of Technology, and JAXA, propose the adhesive based sampling system for next minorbody explorers. By using this sampling system, it becomes possible to get larger size and heavier mass samples compare with the samples which are able to get by HAYABUSA's sampling system. In this paper, Description of the adhesive based sampling system, results of evaluation experiments and analysis of the sampling mechanism are described and discussed.

始原小天体有機物は、太陽系および生命原材料物質の起源と進化を理解するための重要な情報を記録している。「たんぽぽ計画」では、大気圏突入時の熱変成や地上での汚染を受けていない宇宙塵を、国際宇宙ステーション上に超低密度シリカエアロゲルを設置して回収を試みる予定である。しかし、この方法では、宇宙塵のエアロゲルへの衝突により変成する可能性を考慮する必要がある。そこで本研究では、宇宙科学研究所・スペースプラズマ実験施設の二段式高速ガス銃を用いて、隕石微粒子の高速衝突模擬実験を行い、マーチソン隕石微粒子をシリカエアロゲルに撃ち込んだものを取り出し、2枚のアルミ板にはさみハンドプレスして圧着された隕石微粒子を、片方のアルミ板に載せた状態で、赤外顕微分光装置と顕微ラマン分光装置で測定を行った。また、SPring-8, BL43IRの高輝度赤外顕微分光装置IFS120HRでイメージング測定を行い、衝突前後の隕石有機物の分子構造の変化を見出すことを目的とした。

The minorbody explorer called "HAYABUSA" conducted sampling mission on the minorbody "ITOKAWA", and now it is planning to develop next minorbody explorers. The LSS, laboratory for space systems at the Tokyo Institute of Technology, and JAXA, propose the adhesive based sampling system for next minorbody explorers. By using this sampling system, it becomes possible to get larger size and heavier mass samples compare with the samples which are able to get by HAYABUSA's sampling system. In this paper, Description of the adhesive based sampling system, results of evaluation experiments and analysis of the sampling mechanism are described and discussed.