Shiyan (SY, ) is a Chinese experimental satellite program consisting of a variety of test satellites. Given the
classified nature of the satellites, Chinese government statements regarding the missions of Shiyan satellites follow the common refrain of agricultural monitoring and space environment observation — the same offered for other classified programs such as the
Tongxin Jishu Shiyan,
Yaogan, and
Shijian
Shijian (, abbr. "SJ") is a series of satellites built and operated by the People's Republic of China. Some Shijian-series satellites have drawn significant concerns from the United States government and space observers who cite unannounced launc ...
programs. Alternatively named Tansuo satellites, Shiyan satellites occupy varying orbits including
low Earth,
polar
Polar may refer to:
Geography
Polar may refer to:
* Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates
* Polar climate, the c ...
sun-synchronous,
geosynchronous, and
highly-elliptical orbits and are believed to accomplish a diverse set of missions from rendezvous proximity operations (RPO) to
earth imaging
Satellite images (also Earth observation imagery, spaceborne photography, or simply satellite photo) are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell ima ...
.
Though similarly named, the Shiyan satellite program is not to be confused with the separate
Shijian satellite program.
Notable satellites
Shiyan 7
Shiyan 7 was launched from
Taiyuan Satellite Launch Center (TSLC) on 19 July 2013 aboard a Launch March 4C rocket into
low Earth,
sun-synchronous orbit
A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...
, accompanied by the Shijian 15 (of unknown mission) and Chuangxin 3.
Three weeks after launch, from 6–9 August 2013, Shiyan 7 performed rendezvous operations with its companion
payload
Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...
, Chuangxin-3, supporting speculations of a
robotic arm-wielding satellite tasked with rendezvous proximity operations (RPO).
Later, Shiyan 7 shifted to rendezvous with
Shijian 7 (of unknown mission) with whom it maintained proximity from 19–20 August 2013 until it maneuvered into a 5 km lower orbit.
Drawing further suspicion, around 19 October 2013, Shiyan 7 maneuvered to a 1 km higher orbit and released a previously untracked object, designated which many believe to be a
subsatellite
A subsatellite, also known as a submoon, or moonmoon, is a "moon of a moon" or a hypothetical natural satellite that orbits the moon of a planet.
It is inferred from the empirical study of natural satellites in the Solar System that subsatellites ...
to RPO experiments.
Such operations, which the Chinese government does not comment on, has sparked debate around the nature of Chinese experimental satellites.
Satellites
See also
*
Yaogan (YG)
*
Shijian (SJ)
*
Tongxin Jishu Shiyan (TJS)
References
Reconnaissance satellites
Earth observation satellites of China
Spacecraft launched by Long March rockets
Satellite series
Military equipment introduced in the 2000s
Satellites of China
{{CNSA space program