China in Space by Brian Harvey

Author:Brian Harvey
Language: eng
Format: epub
ISBN: 9783030195885
Publisher: Springer International Publishing

Geosynchronous weather satellites: Fengyun 2, 4

For the Chinese, the next stage was to operate a weather satellite in geosynchronous orbit. Called the Fengyun 2, this would complement the Fengyun 1 series. The concept was that Fengyun 2 would constantly scan China and the western Pacific, sending back pictures from its high vantage point 36,000km out, while Fengyun 1 and 3 would send back detailed weather maps from their lower, regular 100-minute passes over China from an altitude of 900km. The locations set for the new series were 86.5°E and 105°E and the original program envisaged two experimental satellites prior to going operational, with three and five channels respectively. The chief designer of the imaging system was Tong Kai (1931–2005), a graduate of the Leningrad Institute of Telecommunications Engineering, who later went on to the navigation satellite project. Construction of ground systems began in 1988 and was completed in 1994.

Geosynchronous meteorological satellites are more expensive, requiring a big launcher and imaging instruments able to operate effectively from such a distance. However, the vantage point of 36,000km can provide quality weather coverage of large land masses round the clock. The United States operated their first geosynchronous weather satellite in 1974 (Synchronous Meteorological Satellite 1), Japan and Europe in 1977 (Himawari and Meteosat respectively) and Russia not until 1994 (Elektro).

Fengyun 2 was a drum-shaped satellite 4.5m tall, with a diameter of 2.1m and a weight of 1,380kg. It carried a five-channel Visible and Infrared Spin Scan Radiometer, which transmitted a visible picture of 2,500 lines and 1,250m resolution every 30 minutes; infrared images of 2,500m resolution; and water vapor images of 2,500m resolution sent to stations in China and Melbourne, Australia. This was intended to provide cloud, temperature and wind maps and was designed by SAST and developed by the Shanghai Aerospace Technology Research Institute of the China Aerospace Corporation, with instruments made by the Institute for Technical Physics in Shanghai. It was built in the Hauyin machinery plant, with a planned service life of three years. The FG-36 solid fuel apogee motor was designed to achieve the final insertion. It was 1.53m long, 900mm diameter, 729kg in weight, with a thrust of 44kN or 289 seconds ISP.

The Fengyun 2 series got off to a disastrous start. When Fengyun 2-1 was being loaded with propellant in the processing hall at the Xi Chang launch site on 2 April 1994, the satellite exploded, killing one technician and injuring 31 others. The satellite itself, valued at over €88 million (¥675 million), was a write-off and it took over three years to redesign the propellant tank system to make sure that this accident would never happen again.

The replacement Fengyun 2-1 was eventually launched on the CZ-3 rocket from Xi Chang at 9pm Beijing time on 10 June 1997. Just 23 minutes after launch, the hydrogen-powered third stage fired to send it on its way to its permanent position at 105°E. By September it had completed its full range of systems testing and was ready for handing over to the state meteorological administration.

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