On-Orbit Satellite Over View

ADEOS is the largest satellite Japan has ever developed having dimensions of 4x4x5m. When the NSCAT antenna and the solar array paddle (approx. 3x24m) are deployed, it has a span of 11m in the flight direction and 29m in the direction to its perpendicular.

The spacecraft consists of a mission module which carries mission instruments and a bus module which carries bus subsystems. Attached to the top panel of the mission module are the NSCAT antenna and the antenna tower. Other mission instruments are located on the earth viewing panel. C&DH, MDP, DT, EPS. AOCS and RCS units are located on the bus module. Each unit has an independent thermal control and a minimum of interfaces with other units; which makes it easier to shorten spacecraft integration and testing period.

The satellite has a launch mass of approx. 3500 kg and an in-orbit power generation capability of approx. 4500w. The Commnications and Data Handling Subsystem (C&DH) has an On board Computer (OBC), which enables automatic, autonomous operation of mission instruments by storing weekly mission operation plans and checking the status of mission instruments. The Inter-Orbital Communications Subsystem (IOCS) transmits observation data via the Communications and broadcast Engineering Test Satellite (COMETS). The Attitude and Orbital Control Subsystem (AOCS) employs a three-axis strap-down attitude detection system and a zero-momentum attitude control system achieving an attitude error of less than 0.3 deg. and an attitude stability of less than 0.003 deg./sec. The Reaction Control Subsystem (RCS) generates the thrust necessary for orbital manuevers using 1 N and 20 N thrusters.

ADEOS carries Technical Engineering Data Acquisition Equipment (TEDA) to measure the space environment the spacecraft travels through. The TEDA monitors radiation absorption, memory malfunction, static charge voltage, and contamination, and analyzes heavy ions.