The Journal of Space Technology and Science
Online ISSN : 2186-4772
Print ISSN : 0911-551X
ISSN-L : 0911-551X
Volume 22, Issue 1
Special Issue on HAYABUSA; Asteroid ITOKAWA Sample Return
Displaying 1-5 of 5 articles from this issue
Articles
  • Hitoshi KUNINAKA, Kazutaka NISHIYAMA, Ikko FUNAKI, Tetsuya YAMADA, Yuk ...
    2006 Volume 22 Issue 1 Pages 1_1-1_10
    Published: 2006
    Released on J-STAGE: August 05, 2014
    JOURNAL FREE ACCESS
    The microwave discharge ion engine “μ10” has a long life and high reliability because of electrodeless plasma generation in both the ion generator and the neutralizer. A single μ10 generates a thrust of 8 mN, specific impulse of 3,200 seconds, and consuming 350 W of electric power. Four μ10s propelled the “Hayabusa” asteroid explorer, launched on May 2003, combining a new orbit change scheme “Delta-V Earth Gravity Assist”. In 2005, Hayabusa, using solar electric propulsion, managed to successfully cover the distance between 0.86 AU and 1.7 AU from Sun in the solar system, as well as rendezvous with, land on, and lift off from the asteroid Itokawa. During the 2-year flight, the ion engine system generated a delta-V of 1,400 m/s while consuming 22 kg of xenon propellant and operating for 25,800 hours. Hayabusa solved failures of reaction wheels and chemical thrusters by means of xenon cold gas jet from the ion engine system and aims to return to Earth in 2010.
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  • Takashi KOMINATO, Masatoshi MATSUOKA, Masashi UO, Tatsuaki HASHlMOTO, ...
    2006 Volume 22 Issue 1 Pages 1_11-1_20
    Published: 2006
    Released on J-STAGE: August 05, 2014
    JOURNAL FREE ACCESS
    Hayabusa spacecraft performed a proximity operation including station keeping and hovering around the asteroid (25143) Itokawa from September to November in 2005. In order to navigate and guide the spacecraft to Itokawa, the spacecraft was equipped with sophisticated autonomous navigation and guidance functions including onboard image processing. Since one of three reaction wheels for attitude control failed in late July of 2005 and the second wheel failed in early October, however, the autonomous guidance did not work as designed. To overcome the unexpected anomalies, an optical navigation technique combined with the radiometric information obtained on the ground was used and the proximity operation around the asteroid could be accomplished as planed. This paper presents how those navigation and guidance in proximity phase were carried out, showing with some flight rcsults.
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  • Hideo MORITA, Ken’ichi SHIRAKAWA, Masashi UO, Tatsuaki HASHI ...
    2006 Volume 22 Issue 1 Pages 1_21-1_31
    Published: 2006
    Released on J-STAGE: August 05, 2014
    JOURNAL FREE ACCESS
    The spacecraft Hayabusa performed the descent flights to the target asteroid ltokawa in November of 2005. The surface of ltokawa has a lot of boulders and there are few flat areas where the spacecraft can touch down safely. With the reaction wheels lost prior to the touchdown events, it was very difficult to control translational motion accurately, since the guidance accuracy of several millimeters per second was requested. To accurately determine the spacecraft position, a landmark tracking scheme with the help of the ground operation was introduced and developed in the Hayabusa mission. The Hayahusa project team developed new tools that combined human assist with the computer aided terminal display. The proposed landmark tracking scheme did contribute to the successful precise navigation to the specified area on the surface. This paper presents a descent navigation method with the landmark tracking used for the Hayahusa mission, including the developed ground operation tools.
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  • Masashi UO, Ken’ichi SHIRAKAWA, Tatsuaki HASIMOTO, Takashi KUB ...
    2006 Volume 22 Issue 1 Pages 1_32-1_41
    Published: 2006
    Released on J-STAGE: August 05, 2014
    JOURNAL FREE ACCESS
    The asteroid exploration spacecraft Hayabusa attempted to touch-down two times in November, 2005. The autonomous guidance and navigation capability is installed aboard the spacecraft, which collects the laser altimeter, laser range finders and navigation cameras information aboard and to estimate where the spacecraft is and to decide the path correction maneuvers toward the asteroid ITOKAWA by itself. The function programmed in Hayabusa includes the image processing designed to detect an artificial target marker location. This paper presents how the touch-down events were carried out by showing the flight results along with the detail of onboard GNC(Guidance, Navigation and Control) system.
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  • Takeshi OSHIMA, Shinji HAGINO, Jun’ichiro KAWAGUCHI
    2006 Volume 22 Issue 1 Pages 1_42-1_51
    Published: 2006
    Released on J-STAGE: August 05, 2014
    JOURNAL FREE ACCESS
    The asteroid explorer “HAYABUSA” went through several accidents, such as (1) first RW (Reaction Wheel) fail, (2) second RW fail, (3) communication link lost believed to be caused by leakage of RCS propellant and (4) RCS (Reaction Control System) fail. We, operation team, adjusted the spacecraft timely and effectively to cope with these situations and managed to operate the spacecraft. In this paper, the methods to cope with the situation mentioned above are described.
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