Yaogan Electro-Optical Reconnaissance Satellites

Yaogan 2, 4, 7, and 8 are believed to be optical-reconnaissance satellites with resolution of possibly 0.8 meters or better. Yaogan 2 was launched in May 2007, and all five of these satellites are apparently still operational (“Yaogan Series,” 2010; “UCS Satellite Database”). Some sources report Yaogan 6 as electro-optical, not radar, but this is probably in error. The Yaogan-2 was launched on a Long March 2D, followed by Yaogan-4 on a Long March 2D and Yoagan-7 on a Long March-2C.

The first three were launched from Jiuquan, though afterwards the program moved to Taiyuan. All were launched into sun-synchronous orbits. There appear to be three generations of the Electro-Optical reconnaissance satellites:

1. Jianbing-6 - The first generation spacecraft [Yaogan-2, -4, -7, -11] were launched into orbits with an inclination of about 97.9°, a period of about 97.5 minutes, and an altitude of about 625 by 655 kilometers.
2. Jianbing-8 - The second generation spacecraft [Yaogan-5, -12, -14] were launched into much lower orbits with an inclination of about 97.3°, a period of about 94 minutes, and an altitude of about 480 by 480 kilometers. Yaogan 12 had a Mean Local Time of the Ascending Node (MLTAN) almost identical with Yaogan-5, and was probably a replacement for this spacecraft, which had been launched almost exactly three years earlier. The Chinese launched Yaogan Weixing series satellite on 27 December 2014. The launch of Yaogan Weixing-26 took place at 03:22 UTC using a Long March-4B launch rocket from the LC9 launch complex at the Taiyuan Satellite Launch Center, reports NASA. The launch, the 202nd mission for the Long March rocket family, probably replaced Yaogan 12.
3. Jianbing-9 - The third generation spacecraft [Yaogan-8, -15, -19] were launched into much higher orbits with an inclination of about 100.5° [unlike the ~97° favored by all other Yaogan spacecraft], a period of about 109 minutes, and an altitude of about 1,200 by 1,200 kilometers.

Neither the launch times nor the RAAN (right ascension of ascending node) of these spacecraft provide any obvious indication of constellation formations, rendering it difficult to judge whether new satellite launches are supplementary to , or replacements for, earlier satellites. The Jianbing-8 and Jianbing-9 programs appear to have consisted of a single initial launch, with the second and third launches remaining operational by the end of 2013. Jianbing-6 is a bit more difficult to judget, but surely at least two spacecraft remained operational by the end of 2013.

Anylasis of public reports from a technological Chinese website (www.9ifly.cn) suggested the resolution of YG5 is about 0.7m-0.8m. And china-defense-mashup reprts that “High Resolution CCD Remote Sensing Camera” is developed by XIOPM (Xi’an Institute of Optics and Precision Mechanics, CAS). The Chief Designer is Li Yingcai (???), who firstly announced the sub-pixel imaging theory of TDI-CCD camera. Then the technological demonstration proved that new theory can raise 1.4 time resolution in dynamic push-broom imagining. The “Yaogan-V” satellite was believed to have an optical design of “Three-Mirror-Anastigmat with Fold Mirror” for the space camera. And the “F” number is 14.4 and long focal distance reaches 7200mm. When “Yaogan-V” at 450km orbit, the swath width can reach 12.5km. And the size of imaging pixel is 10 µm, the ground imagine single pixel resolution can reach 0.62m.

On JB-9 there exists a publication on the use of JPEG2000 compression in XX-9 project due to high resolution (0.1 meters) and very high real-time data flow. The optical satellites are reportedly built by SpaceSat/CAST, based on the CAST-2000 platform. CAST2000 is a compact satellite platform characterized by its high performance, expandability and flexibility. It is fitted with an S-band TT&C sub-system, X-band data transmission sub-system and 3-axis attitude stabilization, and is able to offer highly precise control, large-range sway maneuver, flexible orbit maneuver, highly integrated housekeeping and highly effective power supply. This platform has already been successfully applied in several Chinese small satellites, including the OceanSat-1A, 1B and Huanjing-A, B satellites, and its performance and reliability have proven to be excellent.

The dry mass [bus and payload] of the standard CAST-2000 is about 1,000 kilograms, a bit more than a third the 2,800 kg payload capacity of the Yaogan CZ-4C launch vehicle. Presumably the difference reflects a larger payload with larger optics, and perhaps more maneuvering propellant.

The Yaogan EO spacecraft replaced China's third generation of imaging satellite, the FSW-3, the last of whichwas launched by a Long March 2-4 from Jiuquan Launch Center in northwestern China on 29 August 2005. China's first recoverable film-return imagery intelligence satellite experienced an initial launch failure on 05 November 1974. On 26 November 1975 a Long March-2 launched China's first sucessful retrievable satellite from the Jiuquan Satellite Launching Center.

On August 10, 1960, after 12 successive failures, the United States launched Discoverer-13, the first successful CORONA satellite. The first mission was a test vehicle that carried an American flag, but no film. The first intelligence operation to return film occurred eight days later. Air Force C-119, and later C-130, planes recovered the film return capsules in mid-air as they drifted downward over the Pacific Ocean. A Kodak facility in Rochester, New York, developed the film, which was then sent to Washington, DC, for analysis. The CORONA program continued until 1972 and produced over 800,000 images.

Developed in the 1960s as CORONA follow-on systems, the KH-7 and KH-9 film-return satellites provided imagery of Soviet and Chinese nuclear installations, missile sites, and other activities in “denied territories.” Between July 1963 and June 1967, NRO operated 38 KH-7 missions. Only 30 missions obtained usable images, totaling about 43,000 linear feet. Between June 1971 and October 1984, NRO conducted 19 KH-9 missions, and attempted a twentieth mission in April 1986, which exploded on launch. The KH-7, America’s first successful high-resolution imagery satellite, complemented the broad area search capabilities of the KH-9. In effect, the KH-9 determined that something was worth seeing on the ground; the KH-7 then acquired the detailed imagery for analysis.

However, de-orbiting capsules, developing the film, and examining the images took weeks; America needed a faster method of gaining intelligence from space. On December 19, 1976, NRO launched the KH-11 near real-time electro-optical satellite. As demand for satellite reconnaissance grew, NRO developed increasingly sophisticated technology to collect and process imagery and signals intelligence.

The KH-11 program helped create charged-coupled device (CCD) technology that allowed for digital capture and radio transmission of imagery to earth. The Soviet Union soon followed this lead. As its Yantar series evolved, the first Soviet satellite with electro-optical capabilities was launched in 1982.

YAOGAN 27 is officially designed "for experiments, land surveys, crop yield estimates and disaster prevention" (Xinhua), but analysts believe the spacecraft is intended to operate as a military spy satellite. The commonalities with some other Chinese orbiters likely mean Yaogan 27 is the next in a sequence of optical reconnaissance satellites designed to supply high-resolution imagery to the Chinese military and intelligence agencies.

China launched its Yaogan-28 remote sensor satellite into space on 08 November 2015 from Taiyuan launch site in Shanxi Province in the north of the country, Xinhua reported. "The satellite will be used for experiments, land surveys, crop yield estimates and disaster relief." The Yaogan-28 was carried into orbit by a Long March-4B rocket. The first "Yaogan" series satellite, Yaogan-1, was launched by China in 2006.

A Long March 2-D rocket carrying the Yaogan-30 remote sensing satellite blasted off at the Jiuquan Satellite Launch Center in Jiuquan, northwest China's Gansu Province, May 15, 2016. China's Yaogan-30 remote sensing satellite was sent into space on Sunday at 10:43 a.m. from Jiuquan in northwestern China's gobi desert. "The satellite will be used for experiments, land surveys, crop yield estimates and disaster relief." Yaogan 30, entered a roughly 626 x 655 km x 98.07 deg sun synchronous low earth orbit.

On 25 January 2018 Xinhua reported that China launched a "series of Yaogan-30" remote sensing satellites at 1:39 p.m.(Beijing Time) Thursday on a Long March-2C carrier rocket from Xichang Satellite Launch Center in southwest China's Sichuan Province.

China successfully sent a group of new remote sensing satellites into orbit from the Xichang Satellite Launch Center in southwest China's Sichuan Province on 26 July 2019. The satellites, belonging to the Yaogan-30 family, were launched by a Long March-2C carrier rocket at 11:57 a.m. (Beijing Time). The satellites have entered the planned orbits, and "will be used for electromagnetic environment detection and related technological tests". The launch was the 308th mission of the Long March rocket series.

At 7:52 on November 28th, the Taiyuan Satellite Launch Center sent good news. The Long March 4C carrier rocket was successfully launched. The high score satellite No. 12 entered the planned orbit, which means the twelfth high score special project. The remote sensing satellite was successfully launched. For China, the high-scoring satellite is of great significance. It can be described as the Chinese's own global observation system. This type of satellite has sub-meter-level ground pixel resolution. It is designed for national census, urban planning, land determination, and road network design. It can provide intelligence support for work in the fields of crop yield assessment and disaster prevention and mitigation. It can also help the development of the Belt and Road project and promote the modernization of national defense.

The project has only been 9 years from the project's establishment to the present. However, from the launch of the first high-scoring satellite in 2015 to the present, 12 have been launched in four years. High-scoring satellites, with an average of three high-scoring satellites taking off each year. This high-efficiency space launch shows that after years of accumulation in China's space industry, it has finally demonstrated its latecomer advantage. In the words of the Navy, China ’s satellite launches are now As fast as dumplings.