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Brigadier
China has made a surprise rocket launch once again, launching a Long March 4B rocket from the Jiquan Satellite Launch Center at 3:50 UTC on Friday to deliver the Shijian 16 satellite to Low Earth Orbit.
According to Chinese media, the satellite's mission will be dedicated to measurements of the space environment close to Earth as well as technology demonstrations - which fits into the agenda of the Shijian series of satellites.
The first Shijian satellite was launched by a Long March 1 rocket in 1971. It was the second satellite launched by China and carried basic science equipment including a Geiger-Müller counter to study the radiation environment in near-Earth Space, orbiting Earth in an elliptical orbit.
Shijian 2, 2A and 2B were three separate satellites equipped with payloads dedicated to scientific research and technology demonstrations. The three satellites were launched aboard a single rocket in 1979. Shijian 2 demonstrated deployable solar arrays, chemical thrusters, C-Band tracking and new thermal control systems while the 2A satellite studied electron abundance in the ionosphere and Shijian 2B featured a deployable balloon on a long wire to serve as a radar target.
The third Shijian series of satellites evolved into its own program, the Ziyuan Remote Sensing satellite program. Shijian 4 was orbited in 1991 and carried six payloads to study near-Earth space radiation in a highly elliptical orbit.
The China Academy of Science built Shijian 5 to demonstrate a new satellite bus to serve as China's first small satellite bus. Additionally, 11 payloads were installed on the vehicle to study space radiation and the microgravity environment.
Four pairs of satellites were launched under the Shijian 6 designation from 2004 to 2010. Officially, those satellites were used to measure the space environment and demonstrate new technologies, but western analysts believe that the SJ-6 series also served military purposes such as Electronic Intelligence. The SJ-6 satellites are operated in a Sun-Synchronous Orbit at 600 Kilometers and with an inclination of 97.7 degrees. The vehicles were built by different contractors. Shijian 7 was a single satellite launched in 2005 carrying a remote sensing instrument, likely an infrared camera in addition to other research equipment.
The Shijian 8 mission in 2008 was a short-duration flight of a satellite with re-entry capsule to demonstrate this technology and perform space biology experiments that returned to Earth aboard the satellite. Part of the payload were seeds that were exposed to the space environment for post-flight studies.
The next in the series, Shijian 9 A&B were launched last year to demonstrate electric propulsion, improved stabilization and control platforms, an advanced power generation and storage system, and new thermal control technology. The vehicles also carried Earth Observation payloads.
Shijian 10 will fly a mission similar to that of Shijian 8 some time in the next three years.
Shijian 12 launched in 2010 and its mission is dedicated to scientific research and technological demonstrations including inter-satellite measurements and orbital maneuvering and rendezvous exercises with other Shijian spacecraft in orbit.
The Shijian 11 series of satellites made its first launch in 2009. Shijian 11-01 and all subsequent spacecraft were designed and manufactured by China Spacesat Co. Ltd. of the China Academy of Space Technology. The satellite constellation was reportedly intended for science and engineering experiments. Shijian 11-03 and 11-02 were launched in July 2011 and SJ-11-04 was planned to follow August but failed to reach orbit. Satellite 11-05, the replacement for 11-04, was launched in July 2013.
Following Friday's launch, China confirmed that the new satellite is named Shijian-16. US Space Surveillance has detected two objects in 599 by 616 and 476 by 603-Kilometer orbits at an inclination of 75 degrees. The orbit and the type of launch vehicle as well as prior hints may suggest that Shijian-16 is the follow-on to the Shijian-6 series, but that has still to be confirmed.