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FSW-0 (Jianbing 1)
FSW-0 (a.k.a. Jianbing 1 in its military designation) was the first-generation recoverable remote-sensing satellite designed for land surveying role. The satellite carried a single prism-type panorama camera to obtain visible and near infrared photographic images of Earth, with an estimated special resolution of 10~15m. Later variant of the satellite was added with a medium-resolution CCD camera to test the real-time imaging technology.
The engineering development of the first FSW-0 satellite began in 1973, with the first launch scheduled to take place in November 1974. The construction of the first FSW satellite was completed in June 1974. The satellite was delivered to the Jiuquan Satellite Launch Centre on 8 September. The CZ-2 launch vehicle arrived four days later.
After initial checks, the CZ-2 rocket was assembled on Pad “138” of the Launch Complex 3. After the final checkout, the rocket was integrated with the satellite and fuelled with the propellants. The launch was originally scheduled at around 13:00 local time (05:00 GMT), but the countdown was stopped at T minus 13 seconds as the satellite suddenly lost its power. After some investigation, the technical staff rectified the problem and the launch was rescheduled to 17:40 local time. However, only 6 seconds after the liftoff, the launch vehicle began to swerve off course. At T + 20 seconds, the self-destruction system was trigged, destroying both the rocket and the satellite.
Later investigation showed that the accident was caused by a disconnected cable that carried the pitch rate signal. The launch failure caused a further delay of 12 months, while the engineers built a new satellite and made improvements to the launch vehicle. The construction of the second satellite (FSW-0-1) was completed in August 1975 and the satellite was delivered to the Jiuquan launch centre on 16 October.
At 11:29:52 local time (03:29:52 GMT) on 26 November 1975, the CZ-2 rocket carrying the FSW-0-1 satellite was successfully launched from the Jiuquan Satellite Launch Centre. The satellite was separated from the rocket’s second-stage as scheduled and was placed into a 173km X 483km orbit at 63° inclination. The ground tracking stations across the country were able to track the satellite in the orbit.
Although the telemetry signals of the satellite showed that everything was working as expected in the first 10 orbits of the flight, the satellite designers were not confident that the satellite would continue flying normally. To avoid losing the satellite, some suggested bringing the recovery of the satellite forward to the 27th or 28th of November. After some careful consideration, the mission control decided to stick to the original schedule to have the satellite fly in orbit for three days.
After orbiting the Earth for 47 times, the ground tracking station sent the recovery command to the satellite to initiate the re-entry sequence. The satellite jettisoned its instrument module and fired the retro-motor to slow down. However, the satellite did not follow its designed re-entry trajectory and missed its targeted landing zone. At 11:06 local time (03:06 GMT) on 29 November, the re-entry capsule landed in Guizhou Province, several hundred kilometres away from the landing zone. The capsule was seriously damaged by the heat during the re-entry, but was successfully recovered with useable films retrieved. The mission provided valuable lessons for the design team to make improvements on subsequent satellites.
The third satellite (FSW-0-2) with improvements in the heat protection was built in May 1976 and was delivered to the launch site in October. The launch was scheduled at 12:22 local time (04:22 GMT) on 7 December. However, the countdown to the launch had to be stopped 2 minutes before the launch, as the swinging arms of the launch pad’s umbilical tower failed to open. It took the ground staff 10 minutes to open the swinging arms manually. The launch sequence was resumed and the satellite was successfully sent into orbit.
Immediately after launch it appeared that satellite was losing pressure in its gas storage for the control thrusters. The mission control was concerned that the satellite would not have enough gas left for the re-entry manoeuvre. The gas leakage also affected the spacecraft’s flying status in orbit. After some consideration, the mission control decided to bring the satellite back as scheduled.
In the 47th orbit, the satellite received the re-entry command from the ground tracking station and initiated its re-entry sequence. The re-entry capsule was separated from the instrument module as scheduled and entered atmosphere in the midday on 12 October. At 12:11 local time (04:11 GMT), the capsule landed in the landing zone. The recovery helicopter arrived at the landing spot within 3 minutes of the landing. The recovery crew was pleased to see the capsule completely intact and the mission was a success.
The fourth satellite (FSW-0-3) was built in 1977. It was launched on 26 January 1978 and was recovered successfully three days later. The mission obtained a large amount of useful remote-sensing images.
After four experimental satellites, the design team was able to finalise the satellite design. From the fifth mission (FSW-0-4), the improved application variant satellite was used. Improvements on the application variant satellite included:
Prolonged mission duration from 3 days to 5 days;
- Increased overall mass from 1,800kg to 1,865kg;
- Resigned space frame with slightly reduced mass;
- The addition of a medium-resolution CCD camera to complement the main film camera;
- Additional telemetry signals to provide more information on the flight status of the re-entry capsule;
- Amendable flight programme to allow more flexibility before and during the mission;
- Encrypted communications for improved security;
- The addition of a radio transponder on the re-entry capsule to help locating its landing spot;
- To be launched by the improved Changzheng 2C (CZ-2C) launch vehicle;
Development of the application variant FSW satellite began in 1977, with the design concept approved in July 1977. Construction of the first application variant satellite (FSW-0-4) began in February 1982, and was successfully launched onboard a CZ-2C launch vehicle on 9 September. The satellite was successfully recovered on 14 September.
Five more missions were launched between 1983 and 1987, with all satellites successfully recovered. Two satellites, FSW-0-5 launched on 21 October 1985 and FSW-0-6 launched on 6 October 1986, were specifically launched for a nation-wide land surveying programme. The two satellites carried both black-and-white and colour films to obtain visible and near infrared photographic images of Earth. FSW-0-6 and FSW-0-7 also carried French and West German microgravity experiment packages inside the re-entry capsule.
Specifications
| Length | 3.14m |
| Diameter | 2.20m |
| Launch mass | 1,800kg (Experimental variant) 1,865kg (Application variant) |
| Payload mass (recoverable) | 260kg |
| Payload mass (non-recoverable) | 340kg |
| Stabilisation | 3-axis (+/-0.1° in all axes) |
| Mission duration | 3 days (Experimental variant) 5 days (Application variant) |
Last updated: 9 May 2012