Fanhui Shi Weixing

返回式卫星
Mock-up inShanghai Museum
Program overview
Country	People's Republic of China
Organization	China Academy of Space Technology (CAST)
Purpose	Reconnaissance, Earth observation, microgravity experiments
Status	Completed
Programme history
Duration	1974–2016
First flight	26 November 1974
Last flight	5 April 2016
Successes	23
Failures	2
Launch site	Jiuquan Satellite Launch Center (JSLC)
Vehicle information
Launch vehicles	Long March 2 Long March 2C Long March 2D

TheFanhui Shi Weixing (simplified Chinese:返回式卫星;traditional Chinese:返回式衛星;pinyin:Fǎnhuí Shì Wèixīng;lit. 'recoverable satellite') series of satellites was China's first reconnaissance satellite program. The satellites were used for military reconnaissance and civilian imagery tasks and completed 23 missions between November 1974 and April 2016. There were four generations of the Fanhui Shi Weixing (FSW) satellites: FSW-0 from 1974 to 1987; FSW-1 from 1987 to 1993; FSW-2 from 1992 to 1996; and FSW-3 from 2003 to 2005. Two derivative models, theShijian-8 (SJ-8) andShijian-10 (SJ-10), were developed and launched as 'seed satellites' conductingbioastronautic experiments for theChinese Ministry of Agriculture. All FSW-series satellites were launched into orbit usingLong March rockets from theJiuquan Satellite Launch Center (JSLC).

The successful recovery of an FSW-0 recoverable satellite in 1974 established China as the third nation to launch and recover a satellite following the United States and the Soviet Union.^{[1][2][3][4][5][6]} This success served as the basis for thesecond Chinese crewed space program, the third crewed program (Project 863) during the late 1980s, and the currentShenzhou program (active since 1992).^[3] A novel feature of the spacecraft'sre-entry module was the use ofimpregnated oak, a natural material, as theablative material for itsheat shield.^[7][8]

The Fanhui Shi Weixing (FSW) imagery reconnaissance satellite program was succeeded by the ongoingYaogan Weixing satellite program which began in 2006 and consists ofimagery,synthetic aperture radar (SAR), andocean surveillancepayloads.

The beginnings of the FSW-0 (military designation "Jianbing-1") recoverable satellite began in 1965 whenQian Xuesen conceived and proposed the idea and, after significant and tragic setbacks, finally completed it in 1974.^[9]

Having returned tomainland China from the United States after pressure fromFBI andKu Klux Klan during theSecond Red Scare, "father of the Chinesemissile program"Qian Xuesen began a remarkably successful career in rocket science, boosted by the reputation he garnered for his past achievements, and eventually rose through theParty's ranks to become aCentral Committee of the Chinese Communist Party member. Purportedly out of his dream of crewed spaceflight but also recognizing the military value,Qian Xuesen urged the Chinese Central Planning Committee to invest in the development of recoverable satellite technologies, similar to those the United States andSoviet Union had been successfully operating since the early 1960s.^[9] Interested more in the military value recoverable satellites would provide, the committee accepted and tasked space physicist and engineerZhao Jiuzhang (who is today known as the "father of theChinese satellite program" for his work as the chief designer of China's first satellite,Dong Fang Hong 1)^[10] to head the project.^[9] Earnest work on the project began in 1965 afterJiuzhang's team submitted a preliminary analysis of requirements having toured military and civilian organizations to assess potential applications of a recoverable satellite program.^[3]Wang Xiji, an American-educated rocket scientist and designer of theLong March 1 rocket which would launch theDong Fang Hong 1 satellite in 1970, was named chief designer of the recoverable satellite program.^[9]

In May 1966,Mao Zedong, with the help of theCultural Revolution Group, launched theCultural Revolution with the stated goal of preservingChinese communism by purging remnants ofcapitalist andtraditional elements fromChinese society and to re-imposeMao Zedong Thought (known outside China as Maoism) as the dominant ideology in China.^[11] Among other groups, the purges of Mao'sRed Guards focused heavily on academics and intellectuals regarded as the "Stinking Old Ninth" which included the seizure of theChinese Academy of Sciences and the persecution of 131 of the 171 senior members and the killings of 229 members.^[12]Zhao Jiuzhang was killed (though some sources say he committedsuicide under the pressures of persecution),Qian Xeusen was reduced to the role of a common worker, andWang Xiji was accused of sabotaging an FSW testparachute for which he fought to prove his innocence. Later in 1971, whenMao's successorLin Biao died in aplane crash following an abortive coup d'état, Mao initiatedan immense witch-hunt to oust potential supporters ofLin Biao. As a result, many departments of theAcademy were closed to include theShuguang project, China's proposed first crewed spacecraft, which had shared much of its technology with the recoverable satellite program costing the team valuable development money and time.^[9] Only after several months of persistent attack byMao's Red Guards didPremier of thePRCZhou Enlai intervene to put fifteen key scientists in critical missile programs under state protection while others did their best to survive the violence.^[3]

Despite the challenges and four years past its goal, theChina Association for Science and Technology (CAST) completed the FSW-0 satellite which weighed 1,800 kilograms and carried photographic film and two cameras intended to support both military and civilian needs.^[13] FSW-0 carried a prism-scanning panoramic camera and a stellar camera both designed by theChangchun Institute of Optics and tested on twoT7A rockets in July 1967.

In 1972, several technician teams were dispatched toLaiyang inShandong,Xinhua inHunan,Lhasa inTibet, andKashgar inXinjiang to establish the nation's first satellite control, tracking, and telemetry stations. Having established four fixed stations and two mobile, technicians tested the control network withSoviet-madeIl-14 aircraft flying at high-altitudes.^[14]

On 8 September 1974, FSW-0 No. 1 was transported to theJiuquan Satellite Launch Center (JSLC) for launch on aLong March 2 rocket (derived from theDongfeng 5 ballistic missile). The first attempt to launch an FSW-0 satellite into orbit on 5 November 1974 failed with the rocket exploding approximately twenty seconds after launch and debris crashing 300 meters from thelaunch pad. Analysis of the recovered debris led Chinese scientists to blamecopper wire damage in the rocket during thesecond stage.^[13][15]

The first successful FSW-0 launched on 26 November 1975 fromJiuquan Satellite Launch Center inInner Mongolia Pad 138, Launch Complex 2.^[16] Immediately after launch, it became apparent the satellite would be irrecoverable due to a loss of pressure in the gas orientation system.Qian Xeusen estimated the chances of recovery to be near zero while Yang Jiachi (developer of the FSW-0'sattitude control system) believed the seeming loss of pressure was only the result of the gasses cooling (Charles's law) as the spacecraft cooled exiting the atmosphere. Despite Yang's adamance that the mission should continue, the decision was made andXian Ground Station commanded the satellite to reenter the atmosphere after only three days flight time.^[1][2][3]

With observers waiting in the mountains ofSichuan, four coal miners seated in a mess hall inGuizhou Province about 400 kilometers away watched a red-hot object crash into a nearby grove of trees around noon. Venturing out to see the crashed object, one reportedly threw a rock and was relieved to hear a metallic sound confirming the object was of terrestrial origin. The miners reported the object to local authorities and the recovery team eventually arrived to find the spacecraft intact and the imagery undamaged.^[3] Thereentry vehicle was damaged by reentry and the parachute partially burned; however, the film was declared undamaged and the mission was deemed a success, making China the third nation to capture space-based imagery after the United States' CORONA satellite in 1960 and the Soviet Union's Zenit satellite in 1962.^{[2][3][4][6][13][5]}

The extracted imagery was in extremely lowresolution and suffered significantdistortion from in-orbit movements; however, the FSW-0 was launched eight more times on an imagery mission with the final mission purposed to conduct microgravity experiments.^[3] Themicrogravity experiments of the last mission tested thesmelting andrecrystallization ofalloys andsemiconductor materials includinggallium arsenide and would continue as part of the larger FSW satellite program.^[17]

The FSW-1 series of reconnaissance satellites represents the application of lessons learned from theFSW-0 series, particularly in stabilizing the imagery obtained in-orbit. Launched one month following the last launch of theFSW-0 series, changes made with the new series included an increased in-orbit time (three days to five days) and precision while imaging was improved from 1° to 0.7°. Themass of the newer satellite increased from 1,800kilograms to 2,100 kilograms and the FSW-1 series was launched into a morecircular orbit with a slightly increasedorbital perigee and reducedorbital apogee. These improvements reportedly improved the accuracy and stability of the collected imagery to improve the quality ofmaps produced.^[1] Unlike its contemporaries, American andSoviet (laterRussian) photographicreconnaissance satellites, and like its predecessor theFSW-0, FSW-1 series satellites had noin-orbit maneuvering capabilities to enable prolonged observations over areas of interest.^[2]

FSW-1 satellites, though believed to be fulfilling a secondary military purpose, were primarilycartographic in purpose featuring a higher-resolution (10–15 meterresolution) camera system and a lower-resolutioncharge-coupled device (CCD) camera (50 meter resolution) that transmitted images to the ground innear-real-time to avoid squandering the limited on-board film used by the higher-resolution camera. The lower-resolution camera was reportedly used to image when unfavorable environmental conditions such ascloud cover prevented the collection of high-quality imagery.^[18]

FSW-1 4 carried in an open trunk below the imaging capsule theSwedishFreja magnetospheric research payload. The nineteen millionUSD 214 kilogramFreja payload was designed by theSwedish Space Corporation on behalf of theSwedish National Space Board and carried eight experiments in the subjects ofelectric fields forSweden's Royal Institute of Technology,magnetic fields forJohns Hopkins University in the United States,cold plasma for theNational Research Council of Canada,hot plasma andwaves for theSwedish Institute of Space Physics,auroral imagery for theUniversity of Calgary in Canada, andelectron beams andparticle correlators for theMax-Planck Institute in Germany.^[19] FSW-1 5 carried, in addition to its earth-imaging payload and microgravity research equipment, adiamond-studdedmedallion commemorating the 100th anniversary ofChairman Mao Zedong's birth.^[18]

Satellites of the FSW-1 series were developed by theChina Academy of Space Technology (CAST), used acelestial camera for positional information, were stabilized by a3-axis system, powered by a FG-23retro motor,battery powered, and communicated at 179.985MHz (VHF).^[18][20][21] After atmospheric reentry, thereentry capsule deployed a singledrogue at high velocities 10–20 kilometers above the ground followed by a mainparachute deployed at a more arrested speed of 5 kilometers altitude to slow the capsule's descent to around 10 meters per second by the time thereentry capsule struck the ground.^[21]

All five FSW-1 series satellites were launched using aLong March-2C rocket from theJiuquan Satellite Launch Center (JSLC) and controlled via theXi'an Satellite Monitor and Control Center (XSCC) inShaanxi Province.^[1] With five successful launches and four successful recoveries, the FSW-1 program was largely a success; however, the failure of the final FSW-1 satellite, in part, marred the legacy of the series by gaining worldwide attention for its uncontrolledorbital decay.^[21]

FSW-1 No. 5, the last satellite of the series, launched on 8 October 1993, experienced a failure in the satellite'sattitude control system which rendered it unable to properly reenter theatmosphere.^[22] The failure of the attitude control system when the satellite was instructed to return on 16 October 1993 tilted the spacecraft 90° from its intended position causing thereentry capsule to enter ahighly elliptical orbit of 179 km × 3,031 km instead of returning to Earth.^[23] The re-entry capsule entered the atmosphere on 12 March 1996 over the SouthAtlantic, in a tumbling fashion which exposed much of the spacecraft unprotected by theheat shield to extreme heat and friction duringreentry. Although the extent of the destruction is unknown,U.S. Space Command reported that some fragments had survived the conditions of reentry that had fallen into thePacific Ocean near the coast ofPeru.^[23] The loss of the FSW-1 5 was the only failed recovery of the larger FSW program.^[21]

Although in the end only a few fragments had likely reached the ocean's surface, the abortive reentry was widely reported onAmerican andEuropean television and in newspapers. Five days before the satellite's atmospheric reentry, the orbit was so unpredictable that studies could guess its reentry time with no less than a 10-hour error and could not predict where the fragments would land nor if it would strike a populated area.^[21][24] Western news followed the updates and predictions released byAir ForceMajor Don Planalp ofU.S. Space Command inColorado and was concerned largely with the novel and potential dangers of heavy metal fragments striking residential areas.^[25] News on the satellite frequently likened the satellite's decay to that of theSovietSalyut-7 and become uniquely enamored with the onboard diamond-studded medallion celebrating the 100th birthday of the lateMao Zedong.^[26] Press organizations were unable to receive a comment from theChinese Embassy in Washington on the satellite's fall as the Chinese government was still tight-lipped on the satellite's existence.^[27][28] Although experts stressed the low probability that the decaying satellite would strike of in a place of significance, some governments did issue be-prepared orders to law enforcement in the case of the potential disaster, most prominently theUnited Kingdom's Home Office.^[29]

The FSW-0 was the first generation of China's returnable satellites.^[30][13][2] Its primary use was for the inspection of national land and natural resources.^[2] First-generation FSW-0 satellites all carried prism-scanpanoramic cameras.^[13] The FSW-0 did not have a complete orbit control system, so its decay orattenuation of orbit was quick, and it had a relatively short orbital duration. Its landing or return location accuracy was also relatively low.^[3]

The next generation, the FSW-1, carried more powerful cameras than its predecessor and was mainly used for drawing maps. Itsspatial resolution was as high as 10m (able to discern objects 10 meters apart). The next two generations were called FSW-2 and FSW-3.

Notes: FSW-3 No. 2 and No. 4 are sometimes referred to as FSW-4 1 and 2 owing to design variations and the military designation's transition from Jianbing-2 to Jianbing-4; however, most sources retain the original FSW-3 name. Because Jianbing-4 No. 1 and No. 2 are differently designed, some sources refer to them as Jianbing-4A (JB-4A) and Jianbing-4B (JB-4B), respectively.

• • 《返回式卫星》 (Returnable Satellite); Author: Lin Baohua (林华宝); Press:Tsinghua University Press,Jinan University Press; (ISBN 7302048827)
  • 《太空情报与国家安全》 (Space Intelligence & National Security); Author: Lin Ziyang (林子洋); Press: Youshi Press; (ISBN 9575744721)

• FSW at Astronautix.com

• Military equipment introduced in the 1970s
• Reconnaissance satellites of China
• Spacecraft launched by Long March rockets

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