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Also called Zi Yuan 1


Designation 25940 / 99057A
Launch date 14 Oct 1999
Country of origin China / Brazil
Mission Remote sensing
Perigee/Apogee 732/745 km, sun-synchronous
Inclination 98.6°
Period repeat period: 20 days
Launch vehicle Long March #56

Worth $150 million

Controlled from both Chinese and Brazilian ground stations. The WFI instrument failed after only 6 months.

End of life

Out of service Probable in 2003?

External resources

sat-index articles

Technical data


Prime contractor CASC/INPE
Mass at launch 1450 kg
Mass in orbit  
Dimension 1.8 x 1.9 m
Solar array 8.3 x 3.3 m
Stabilization 3-axis
DC power  
Design lifetime 2 years

Downlink freq: 180.011, 462.5 and 480.025 MHz. Other frequencies registered are 401.63, 2204.4, 2267.515, 8210 & 8209 MHz

In Oct 2001, the Chinese announce their instruments are still working.

5-channel linear CCD detector (visible, IR, panchromatic)

Wavebands 0.59-0.89 µm
0.5-12.9 µm
Swath width 113 km
Resolution Visible: 19 m
IR: 80 m
Sideway pointing: +/- 32°

Wide-field imager

Wavebands 0.66 µm (green)
0.83 µm (near IR)
Resolution 260 m
Swath width 890 km

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