Yaogan
The Jianbing 5 family of Yaogan satellites, with military designations beginning with "JB-5", are China's first space-based synthetic aperture radar (SAR) systems. These satellites, whose developmental funding was provided in full by the People's Liberation Army (PLA), are built by the Shanghai Academy of Spaceflight Technology (SAST) and launched from the Taiyun Satellite Launch Center (TSLC) and provide military analysts radar imagery purportedly at a resolution as high as 5 meters over the L-band (1–2 GHz). JB-5 satellites have been confirmed to have an electronic motor-powered solar panel which can be expanded and contracted by the ground control station. Jianbing 5 family of satellites have a reported mass of 2,700 kilograms and an orbital inclination of approximately 97° in sun-synchronous orbit. As of May 2022, China has launched eight individual Yaogan satellites of the Jianbing 5 family with the first launch in April 2006 and the most recent in November 2015. Yaogan 1, launched in April 2006, reportedly broke up around 4 February 2010 almost four years after its launch. Due to the small number of pieces and low orbital speeds, the breakup was likely due to an internal explosion, not a high-speed collision. The Jianbing 7 family of Yaogan satellites, with military designations beginning with "JB-6", are Chinese military radar reconnaissance satellites with an orbital period of 97 minutes. As of May 2022, China has launched four Jianbing 7 radar satellites with the first launched in April 2009 and the latest in November 2014 with a mass of 1,200 kilograms (2,600 pounds). Although the JB designation number is still unknown for this family, China has launched three satellites of a modernized successor family to the Jianbing 5 family of SAR reconnaissance satellites. This family uses the same orbit as the JB-5 family but likely has a different design according to published illustrations. The second satellite of this family, Yaogan 33, failed to reach orbit in May of 2019. It's likely replacement, Yaogan 33R, was launched a year and a half later but used different launch site (Jiuquan instead of Taiyuan) and into a higher orbit (682 km × 686 km). The Jianbing 6 family of Yaogan satellites, with military designations beginning with "JB-6", provides the Chinese military optical imaging capabilities to compliment the Jianbing 5 family's SAR reconnaissance capabilities. It has been reported that the Jianbing 6 family have a resolution of 0.8 meters. As of May 2022, China has launched five individually launched Yaogan satellites of the Jianbing 6 family with the first launched in May 2006 and the latest in May 2016. The Jianbing 9 family of Yaogan satellites, with military designations beginning with "JB-9" provides the Chinese military with optical imaging capabilities, likely as a successor to the Jianbing 6 family. The optical payload of Yaogan satellites in the Jianbing 9 family was developed by the Changchun Light Technology Institute. As of May 2022, China has launched five individually launched Yaogan satellites of the Jianbing 9 family with the first launched in December 2009 and the latest in August 2015. The Jianbing 10 family of Yaogan satellites, with military designations beginning with "JB-10" provides the Chinese military with optical imaging capabilities, likely as a successor to the Jianbing 3 family. As of May 2022, China has launched three individually launched Yaogan satellites of the Jianbing 10 family with the first launched in December 2008 and the reported last of the family in September 2014. The Jianbing 11 family of Yaogan satellites, with military designations beginning with "JB-11" provides the Chinese military with optical imaging capabilities. As of May 2022, China has launched two individually launched Yaogan satellites of the Jianbing 11 family with the first launched in May 2012 and the latest in November 2015. The Jianbing 12 family of Yaogan satellites, with military designations beginning with "JB-12", are military optical reconnaissance satellites. The Jianbing 8 family of Yaogan satellites, with military designations beginning with "JB-8", consist of one primary satellite and two sub-satellites launched in triplets. These satellites reportedly perform a ocean or naval surveillance mission similar to those of the United States' Naval Ocean Surveillance System (NOSS or PARCAE). The triplet groups likely fly in a loose formation to locate radio emitters using the difference in time of arrival of radio signals at the different satellites. Jianbing 8 satellites have a mass of 200 kilograms (440 pounds) and an orbital period of 107.10 minutes. As of May 2022, there have been nine launches of Jianbing 8 triplets (twenty-seven total satellites) with the first triplet launching in March 2010 and the latest in March 2021.
Synthetic Aperture Radar (SAR)
Yaogan () is a broad term that refers to the various families of Chinese military reconnaissance satellites.