The Mission Operations of HAYABUSA Asteroid Explorer

Paper number

IAC-06-C1.6.06

Author

Mr. Takeshi Oshima, NEC TOSHIBA Space Systems (NTS), Japan

Coauthor

Dr. Junichiro Kawaguchi, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Mr. Shinji Hagino, NEC TOSHIBA Space Systems (NTS), Japan

Year

2006

Abstract

HAYABUSA is the Asteroid Explorer that touched down and left an asteroid first time in the world. In this paper, the Mission Operations of HAYABUSA are described in three aspects.

    Fist aspect is the Automatization. HAYABUSA has two components that have automatic control functions; one is DHU (Data Handling Unit) and the other is AOCU (Attitude and Orbit Control Unit). DHU has three different functions; Macro Command, Time Line and System Timer. The Macro Command is the command package which is executed together. The Time Line is the command sequence designated in absolute time. System Timer is a kind of Watch Dog Timer, which execute designated command when time is up. AOCU also has another two functions; GSP (Guidance Sequence Program) Macro Command, GSP Time Line Command. The functional decomposition between DHU and AOCU is described. Moreover, how these functions work together in touch down phase is described.

    Second aspect is Autonomy (Onboard Feedback). HAYABUSA also has two components that have autonomous functions; one is DHU and the other is AOCU. DHU has two autonomous functions; General Purpose Autonomy and Request Command. General Purpose Autonomy is the function, which execute designated command when designated HK (House Keeping) Data meets designated condition. Request Command is the function to allow any component to trigger the execution of command to the other component. AOCU has GSP Command Table, which execute command at the designated condition. The functional decomposition between DHU and AOCU is described. Moreover, how these functions work together in touch down phase is described.

    Last aspect is Real Time Operation (Human Feedback). For the decision making, HAYABUSA has four kinds of Packet; Report Packet, HK Packet, Status Packet and Mission Packet. These packets are outputted on demand in accordance with the telemetry mode. The functional decomposition among these kinds of Telemetry is described. HAYABUSA also has flexible reproduce data method. How these telemetries were used in decision making process in touch down phase is described.

Abstract document

IAC-06-C1.6.06.pdf

Manuscript document

IAC-06-C1.6.06.pdf (🔒 authorized access only).

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