@inproceedings{oai:jaxa.repo.nii.ac.jp:00008068, author = {大登, 裕樹 and 山本, 真裕 and 江黒, 高志 and 曽根, 理嗣 and 廣瀬, 和之 and 田島, 道夫 and Oto, Hiroki and Yamamoto, Masahiro and Eguro, Takashi and Sone, Yoshitsugu and Hirose, Kazuyuki and Tajima, Michio}, book = {第25回宇宙エネルギーシンポジウム 平成17年度, The Twenty-fifth Space Energy Symposium March 10, 2006}, month = {Jun}, note = {Li ion batteries for space applications possess high discharge voltage, high specific energy, and lightweight properties, their research and development being conducted rapidly in recent years not only in the U.S. and France but also in Japan. Because of its weight reduction, the asteroid sample return mission spacecraft, HAYABUSA (MUSES-C before launch), which was launched in May 2003 and will bring back samples of the asteroid subsequently named ITOKAWA, 1998SF36, to the earth in June 2010, carried a Li ion battery with a specific energy of more than 85 Wh/kg. The battery consists of 11 prismatic cells with a rated capacity of 13.2 Ah, which are connected in series to supply power required to loads at a bus voltage of about 50 V during a discharge period. We have already conducted the reset operation three times successfully in orbit after the launch. By the effect of the reset operation, the balance of SOC (State of Charge) of each cell was kept. In swing-by operation in May 2004, we navigated the spacecraft in earnest only with the Li ion battery. And then, evaluating the first capacity test of the onboard battery in July 2004, of the spare cells conducted on the ground at the same time. As a result, it has been confirmed that the capacity degradation of the onboard battery is as predicted according to the simulation model, and agreed with capacity degradation of the spare cells. HAYABUSA arrived at ITOKAWA in 2005 autumn. Battery was to be discharged in terminator observations to take images of the asteroid and touch down on it to collect its samples, but there was not the opportunity. The result of the assumption examination by the spare cells on the ground, we considered that the battery had achieved the load capacity which is required by these operations., 資料番号: AA0049121002}, pages = {6--10}, publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)}, title = {はやぶさ搭載バッテリーセルの運用経過(2)}, year = {2006} }