Mission background

After mission completion of JERS-1, NASDA (National Space Development Agency of Japan) was disbanded when it became part of JAXA - the Japanese space agency – who manage the legacy data.

Satellite design

The JERS-1 spacecraft, built by Mitsubishi Electric Co. as prime contractor, consists of a net rectangular bus with a single 2 kW solar array (3.5 m x 7.0 m) and an eight-segmented SAR antenna. The spacecraft is three-axis stabilised with zero momentum bias system using reaction wheels and magnetotorquers.

The attitude is sensed by an Earth sensor, an inertial reference unit and two sun sensors (0.3° attitude knowledge). A hydrazine propulsion system is used for orbit maintenance.

The spacecraft carried two closely-matched Earth observation sensors: the active SAR instrument and the passive OPS multispectral imager.


Mass 1400 kg
Dimensions 0.9 m x 1.8 m x 3.2 m
Design lifetime 2 years

Mission Operations

JERS-1 maintained a Sun-synchronous polar orbit with an altitude of 568 km and a period of 96 minutes. It crossed the equator north to south between 10:30 and 11:00 local time.

NASDA’s EOC (Earth Observation Centre) was responsible for data acquisition, processing, distribution and archiving. There were 10 licensed receiving stations inside and outside Japan.


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