Fanhuishi Shiyan Weixing (FSW)

Official Name: Fanhuishi Shiyan Weixing (FSW)
Military Name: JianBing
Contractor: China Academy of Space Technology (5th Space Academy)
Type: Imagery intelligence, recoverable
Orbit: LEO
First Launch: 1974
Last Launch: 2006
No. of Launches: 23
Service Status: Retired

Fanhuishi Shiyan Weixing (FSW, 返回式试验卫星), or recoverable test satellite in its English translation, is a series of satellites launched by China between 1974 and 2006. The FSW satellite was designed for imagery intelligence (IMINT) and mapping roles, and had a secondary role for scientific research and experiments by using piggyback payload. China is known to have used the FSW satellite for many research projects in micro-gravity and life science research including crystal and protein growth, cell cultivation, crop breeding, etc. The FSW satellite technology also served as the basis for China’s ShenZhou manned spacecraft design.

Between 1974 and 2006, twenty-four FSW satellites were launched aboard CZ-2, CZ-2C or CZ-2D rockets, with one launch failure and one recovery failure. A total of six variants of the FSW satellite were introduced, including five military IMINT variants FSW-0, FSW-1, FSW-2 , FSW-3, and FSW-4, and a scientific experiment variant ShiJian-8 (SJ-8), all of which were launched from the Jiuquan Satellite Launch Centre (Shuang Cheng Tzu missile and space centre). The FSW series satellite has now been replaced by the new generation digital and radar imaging “Remote Sensing Satellites”.

FSW-0 / JianBing 1

The early variant FSW-0 or FSW-1 recoverable satellite (Chinese Internet)

Following the success of the Soviet Union and United States in launching and recovering the recoverable satellite, China began to develop its own recoverable satellite in 1966. The first Chinese-made recoverable satellite had a military designation JianBing 1 ( 尖兵一号), but it was better known as FSW-0 by Western intelligence. The FSW-0/JB-1 was a film return type satellite, carrying a single prism-scanning panoramic camera that offered low-resolution, high coverage-area satellite images. The photograph films were returned to the Earth by a re-entry capsule. The later variant FSW-0 Batch 02 also carried a CCD camera to experiment the digital imaging transmission. Between 1975 and 1987, a total of nine FSW-0 satellites have been launched, all of which were recovered successfully.

The FSW-0 has a blunt conical shape with a total mass of 1,790kg. The satellite is divided into two sections: the equipment module (1.644m in length) and the re-entry capsule (1.500m in length). The retro-motor is carried inside the re-entry module. The battery-powered satellite is three-axis stabilised and can remain in the orbit for 3~5 days. The satellite is equipped with a redundant flight control computer, an inertial measurement unit, and a celestial navigation camera. It employs a cold gas thrust system for orientation.

China made its first attempt to launch the FSW-0 on 5 November 1974 from the Jiuquan Satellite Launch Centre, but the CZ-2 launch vehicle carrying the FSW-0 satellite exploded in the midair 20 seconds after take-off due to a disconnected cable for the rocket’s pitch rate gyro signal.

A second launch was carried out on 26 November 1975. The satellite (FSW-0 No.1) was successfully placed into the low earth orbit (Perigee: 183km; Apogee: 483km; Inclination: 63.00 deg). However, immediately after the launch the satellite began to lose pressure in its compressed air tank crucial for the satellite’s recovery. After careful consideration, the mission control decided not to bring the satellite back early so that the scheduled filming could be carried out. On day three the lost of air pressure stopped and the satellite successfully entered the re-entry trajectory under the ground command. At around 11:00 hour on 29 November, the re-entry capsule of FSW-0 No.1 landed in Liupanzhi, Guizhou Province, about 400km off the targeted landing spot. The photograph films were retrieved successfully.

A FSW-1 satellite being integrated with the CZ-2C space launch vehicle on the launch pad (Chinese Internet)

The improved FSW-0 No.2 was launched and recovered in December 1976. Since then, the FSW-0 launch mission had been carried out on a regular basis from the Jiuquan Satellite Launch Centre, normally once a year between August and December. The last mission FSW-0 No.9 was carried out in August 1987.

Specifications: Typical orbit: 170 x 500km, 57~63 deg inclination; Length: 3.14m; Maximum Diameter: 2.20m; Mass: 1,790kg; Payload: 750kg; Typical mission duration: 3~5 days.

FSW-1 / JianBing 1A

The improved FSW-1, or JianBing 1A in its military designation, was China’s first mapping satellite. It was based on the FSW-0 design, but carried a fix-lens panoramic camera to provide high-precision imagery used for mapping and survey. A total of five launches were carried out between September 1987 and October 1993, with four successfully recovered.

The FSW-1 No.5 launched on 8 October 1993 lost control after eight days of flight due to an attitude control system failure, which caused the capsule to be pushed into a higher elliptical orbit (179 X 3,031km) instead of returning to the Earth. Natural decay did not bring the capsule back until 12 March 1996. This was the only failed recovery of the entire FSW programme.

Specifications: Typical orbit: 170 x 500km, 57~63 deg inclination; Length: 4.60m; Maximum Diameter: 2.20m; Mass: 1,790kg; Payload: 750kg; Typical mission duration: 8 days.

FSW-2 with an extended cylinder-shape section for additional room inside the equipment module (Chinese Internet)

FSW-2 / JianBing 1B

The FSW-2, or JianBing 1B in its military designation, was China’s second-generation low-resolution, high coverage-area imagery intelligence satellite, equipped with a single full-rotation (scanning) type panoramic camera. The FSW-2 was based on the FSW-0/1 design featuring a blunt conical shape nose, but was extended with a cylinder-shape section. In order to give a greater recoverable payload, the retro-motor is accommodated in a separate module, which is separated from the re-entry capsule before it enters the atmosphere. After the re-entry capsule returns, the equipment module of the FSW-2 can remain in the orbit for an extended period of time, allowing further experiments to be carried out. Three FSW-2 satellites were launched between 1992 and 1996, all recovered successfully.

Specifications: Typical orbit: 170 x 500km, 57~63 deg inclination; Length: 4.60m; Maximum Diameter: 2.20m; Mass: 1,790kg; Payload: 750kg; Typical mission duration: 5~8 days.

FSW-3 / JianBing 2

The FSW programme went quiet after 1996, with no launch carried out for seven years. Development of a new generation FSW satellite FSW-3, or JianBing 2 in its military designation, began in 1999. The FSW-3 was China’s second-generation mapping satellite, designed to provide high-precision imagery used for mapping and survey. Like the FSW-2, the FSW-3 also featured a blunt conical shape re-entry capsule and a cylinder shape retrofire and equipment module, but with its cylinder section further stretched to give additional room in the equipment module.

The new generation FSW-3/4 features a further extended cylinder section and increased weight (Chinese Internet)

The FSW-3 was equipped with a higher resolution (10~15m) panoramic film camera and a CCD camera with a lower resolution (~50m). The films were developed on Earth after it was retrieved from the landed re-entry capsule, while the CCD camera could transmit its images to the ground in a near-real-time manner. This combination enables the satellite to use the CCD camera with a wider field of view for high coverage-area scanning, and then use the higher-resolution film camera to only capture areas of interest in order to reduce the wastage of films.

The FSW-3 also employs a number of new technologies to improve the satellite’s performance, including replacing the silver-zinc secondary battery with a high-capacity Lithium battery, which extended the flight time of the satellite to 27 days. In order to achieve better recovery precision, the FSW-3 uses the unified S-band (USB) system coupled with a GPS system.

The design work was completed in March 2002, and the first satellite was tested in September 2002. The FSW-3 No.1 was launched by a CZ-2D launch vehicle from the SLS-2 launch pad in Jiuquan on 2 November 2003. The satellite was successfully recovered 19 days later. The FSW-3 No.2 was completed in July 2004. It was launched by a CZ-2D from Jiuquan on 27 September 2004. The re-entry capsule returned to Earth 17 days after the launch, but apparently missed the targeted recovery zone and landed into a residential area in Daying County, Sichuan Province. The last satellite FSW-3 No.3 was completed in June 2005. It was launched and recovered between August to September 2005.

Specifications: Length: 5.14m; Maximum Diameter: 2.20m; Mass: 3,600kg; Typical mission duration: 18 days.

FSW-4 / JianBing 4

The FSW-4, or JianBing 4 in its military designation, was developed in 2000 in parallel to the FSW-3. The satellite was equipped with a high-resolution (<10m?) film camera, and possibly a lower-resolution CCD camera for high coverage-area scanning. Unconfirmed reports suggested that the FSW-3 may have also been equipped with an IR scanner. The FSW-4 shares the same platform design and certain onboard equipment with the FSW-3, but with a slightly increased mass.

The FSW-4 No.01 was completed in July 2004. The satellite was launched from Jiuquan by a CZ-2C launch vehicle on 29 August 2004. The No.02 satellite was completed in June 2005 and launched on 2 August the same year. Both satellites were successfully recovered after 27 days of flight.

Specifications: Length: 5.14m; Maximum Diameter: 2.20m; Mass: 3,900kg; Typical mission duration: 27 days.

The re-entry capsule of the SJ-8 'seed satellite' (Chinese Internet)

ShiJian 8

The ShiJian 8 (SJ-8) was a scientific research satellite based on the FSW-3 design. The satellite was used to carry a large payload of seeds and exposed it to the space environment for two weeks. Only one mission was carried out in September 2006, and the re-entry capsule was successfully recovered 15 days later. The was the last flight mission of the FSW series satellites.

Specifications: Length: 5.14m; Maximum Diameter: 2.20m; Mass: 3,400kg; Typical mission duration: 15 days.