Fengyun 1A

Description

In 1988 and again in 1990 the People's Republic of China launched FY-1 (Feng Yun - Wind and Cloud) meterological satellites into approximately 900 km, 99 degree inclination orbits by CZ-4 boosters from the Taiyuan space center. The spacecraft were designed to be comparable to existing international LEO meteorological and remote sensing systems, including APT transmissions in the 137 MHz band. The satellite structure and support systems were created by the Shanghai Satellite Engineering and Research Center of the China Space Technology Institute, whereas the payload was developed by the Shanghai Technical Physics Institute of the Chinese Academy of Sciences.

Both satellites were experimental to test systems prior to the launch of operational Feng Yun 1 spacecraft and were similar in design, although technical characteristics differed. The height of the cubical spacecraft bus (1.4 m by 1.4 m base) of Feng Yun 1A was apparently increased from 1.2 m to nearly 1.8 m for Feng Yun 1B. Likewise, total spacecraft mass increased from 750 kg to about 880 kg. Both satellites were powered by two solar arrays (about 3.5 m long each) with a combined rating of more than 800 W. Nickel- cadmium batteries were used for electrical power storage. Attitude control was maintained by a combination of nitrogen cold gas thrusters and reaction wheels, although both spacecraft suffered serious malfunctions in this system. Feng Yun 1A was lost after only 38 days, but Feng Yun 1B operated for more than a year.

The Feng Yun 1 primary payload consisted of two Very High Resolution Scanning Radiometers (VHRSR) with a combined mass of 95 kg. These optical-mechanical scanners operated at 360 rpm with a 20-cm diameter primary mirror. The five spectral bands used were 0.58-0.68 um, 0.725-1.1 um, 0.48-0.53 um, 053-0.58 um, and 10.5-12.5 um. The system swath was 2,860 km with a 1.08-km resolution in the High Resolution Picture Transmission (HRPT) mode and 4-km resolution in the Automatic Picture Transmission (APT) mode.