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Space


FSW-1 (FSW-1A) Imagery Intelligence

The second model of China's retrievable reconnaissance satellites was also called "photographic surveying satellites," which appeared to be high-resolution detailed survey satellites. These satellites weighed about 2,100 kilograms, and a total of five such satellites were launched between 1987 and 1993. One launched in 1993 was not recovered as planned, and reportedly this was the model that failed to return to earth.

The satellite pictures obtained had a high geometrical accuracy and had great military value as they could be used for the accurate positioning of ground "targets of interest" and for the production of maps. The area covered by each satellite picture is 140 times that of aerial photos and 12.4 times more efficient than field operations.

Launched by the CZ-2C booster from Jiuquan, the FSW-1 has a blunt conical shape with a length of 3.14 m, and a maximum diameter of 2.2 m, and a mass of up to 2.1 metric tons. The vehicle is divided into two major sections: the equipment and retro module (1.6 m long) and the reentry module (1.5 m long). The 3-axis-stabilized FSW-1 is powered by batteries and is controlled from the Xian Satellite Control Center. The nominal flight duration is 7-10 days (References 609-611).

FSW-1 satellites have carried imaging payloads with high resolution (10-15 m) cameras for film development on Earth and with CCD (50-m resolution) camera systems for near-realtime images. The latter system can also beused in directing the operation of the former system, thereby minimizing the wastage of film supplies if environmental conditions are unfavorable, e.g., cloud-covered. The maximum recoverable payload is 180 kg, while the maximum non-recoverable payload is 250 kg (References 611-614).

Unlike Russian photo recon satellites, FSW-1 spacecraft do not perform orbital maneuvers to adjust their groundtracks for prolonged observations over areas of high interest. Typical FSW-1 orbital parameters of 210 km by 310 km at inclinations of 57-63 degrees would permit high resolution photography, but the acknowledged sensors are only capable of 10-15 m resolution (film return) or 50 m resolution (digital transmission).

The FSW-1 model was introduced in September 1987. The FSW-1 series of imagery intelligence spacecraft have a demonstrated operational period of up to eight days. FSW satellites were normally flown only once each year and usually in the August-October period.

The last FSW-1 mission was launched on 8 October 1993 into an orbit of 209 km by 300 km at an inclination of 57.0 degrees. In addition to an Earth observation payload, FSW-1 5 carried microgravity research equipment and a diamond-studded medallion commemorating the 100th anniversary of Chairman Mao Tse-Tung's birth. The spacecraft operated normally until 16 October when an attempt to recover the satellite failed. An attitude control system failure aligned the spacecraft 90 degrees from its desired position, causing the reentry capsule to be pushed into a higher elliptical orbit (179 km by 3031 km) instead of returning to Earth. (References 615-620).

The re-entry capsule re-entered on 12 March 1996, over the South Atlantic, falling in a tumbling motion which rendered its protective heat shield ineffective. Consequently, only a few fragments of the spacecraft reached the ocean surface. The reentry was widely reported by newspapers and television, as it was not known whether fragments, or indeed the whole spacecraft, would reach the Earth's surface. Such uncontrolled re- entries pose a potential risk to the population in the area covered by the object's orbit. There were prediction errors of about 10 hours five days before its atmospheric reentry and about 4 hours three days before the reentry. The level of prediction accuracy was such that at five days before the reentry the satellite could have reenterd anywhere on the Earth.

There have been no launches of the FSW-1 spacecraft since the 1993 flight.





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Page last modified: 21-07-2011 00:50:14 ZULU