TJS, ) is a Chinese military

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

program operating in

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular orbit, circular geosynchronous or ...

(GEO). TJS satellites are manufactured by the

Shanghai Academy of Spaceflight Technology The Shanghai Academy of Spaceflight Technology (SAST) is a Chinese space agency and subordinate of China Aerospace Science and Technology Corporation (CASC), it is referred to as ''The Eighth Academy'' of CASC. The agency was established in Augu ...

(SAST) and launched from

Xichang Satellite Launch Center The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport in China. It is located in (), Mianning county, approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. It is op ...

(XSLC) in China's southern

Sichuan Province Sichuan is a Provinces of China, province in Southwestern China, occupying the Sichuan Basin and Tibetan Plateau—between the Jinsha River to the west, the Daba Mountains to the north, and the Yunnan–Guizhou Plateau to the south. Its capita ...

. TJS is likely the cover name for multiple geostationary military satellite programs and should not be confused with the similarly named Shiyan satellite program. Unlike traditional, non-military satellites where the Chinese government announces the satellite's name, mission, platform,

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

, and

launch site A spaceport or cosmodrome is a site for launching or receiving spacecraft, by analogy to a seaport for ships or an airport for aircraft. The word ''spaceport''—and even more so ''cosmodrome''—has traditionally referred to sites capable of ...

in advance, with TJS satellites the Chinese government announces airspace closures the day before and makes vague statements on the satellite's purpose after the launch. Although the true purpose of TJS satellites remains

classified Classified may refer to: General *Classified information, material that a government body deems to be sensitive *Classified advertising or "classifieds" Music *Classified (rapper) (born 1977), Canadian rapper * The Classified, a 1980s American ro ...

, satellite observers speculate these satellites provide early warning and

signals intelligence Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly u ...

(

SIGINT Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly u ...

) for the Chinese

People's Liberation Army The People's Liberation Army (PLA) is the military of the Chinese Communist Party (CCP) and the People's Republic of China (PRC). It consists of four Military branch, services—People's Liberation Army Ground Force, Ground Force, People's ...

(PLA).

Classes

Satellites under the Tongxin Jishu Shiyan cover appear to compose three separate classes, all in geostationary orbit and performing a military or intelligence mission. These include the purported Qianshao-3 SIGINT class, the Huoyan-1 early warning class, and an unknown class for TJS-3 and its subsatellite.

Qianshao-3

TJS-1, TJS-4, and TJS-9 satellites, launched in 2015, 2019, and 2021, maintain geostationary orbit over the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

and

Micronesia Micronesia (, ) is a subregion of Oceania, consisting of approximately 2,000 small islands in the Northwestern Pacific Ocean. It has a close shared cultural history with three other island regions: Maritime Southeast Asia to the west, Poly ...

and are suspected to comprise the Qianshao-3 SIGINT satellite class (). The Chinese government originally stated these satellites were designed to test

Ka-band The Ka band (pronounced as either "kay-ay band" or "ka band") is a portion of the microwave part of the electromagnetic spectrum. The designation "Ka-band" is from Kurz-above, which stems from the German word ''kurz,'' meaning "short". There ...

broadband In telecommunications, broadband or high speed is the wide-bandwidth (signal processing), bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Inter ...

communication (27–40 GHz) but has not commented on the satellites since they achieved geostationary orbit. In January 2017, novel reports of an antenna approximately 32 meters wide reinforced speculation of the satellite's potential SIGINT mission. Other Chinese sources suggest the Qianshao series are space-based infrared early warning satellites.

Huoyan-1

TJS-2, TJS-5, TJS-6 and TJS-7 satellites are, according to official Chinese statements "new generation high capacity experimental communications and broadcasting satellites" testing "high speed and multi-frequency wide-band data transfer." Launched in 2017, 2020, and 2021, these satellites are rumored to be of the Huoyan-1 () program — China's first early-warning satellites in geosynchronous orbit. Placeholder images used in the launch video depicts the satellites as being roughly analogus to the

Space Based Infrared System The Space-Based Infrared System (SBIRS) is a United States Space Force system intended to meet the United States' Department of Defense infrared space surveillance needs through the first two to three decades of the 21st century. The SBIRS prog ...

(SBIRS) of the United States. These purported Huoyan-1 series satellites remain fixed in orbit over the Indian Ocean, South China Sea, and Oceania.

James Acton James Acton (11 October 1848 – 22 August 1924) was an English first-class cricketer. Acton was born at Southampton in October 1848. In Southampton, he initially played club cricket for Southampton Cricket Club, prior to its dissolution in O ...

, co-director of the Nuclear Policy Program at the

Carnegie Endowment for International Peace The Carnegie Endowment for International Peace (CEIP) is a nonpartisan international affairs think tank headquartered in Washington, D.C., with operations in Europe, South Asia, East Asia, and the Middle East, as well as the United States. Foun ...

believes these satellites primary purpose is for missile warning based on their orbital slots and inclinations.

TJS-3 satellites

The third satellite of the Tongxin Jishu Shiyan program, TJS-3, is still largely shrouded in secrecy with observers unable to determine if the satellite performs an early warning or signals intelligence mission. Said to have only had one

payload Payload is the object or the entity that 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 t ...

aboard during its 2018 launch, observers detected a secondary object separate from TJS-3 in orbit. The object was originally labeled by the

United States Space Force The United States Space Force (USSF) is the space force branch of the United States Department of Defense. It is one of the six United States Armed Forces, armed forces of the United States and one of the eight uniformed services of the Unite ...

as an

apogee kick motor An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final orbit (most commonly circular). For a satellite laun ...

(AKM), a final-impulse motor often discarded by satellites entering their terminal geostationary orbit. The secondary object drew public intrigue when, on January 4 and January 11, 2019 (weeks after launch), the secondary object performed station-keeping maneuvers to maintain a synchronized orbit with the main TJS-3 satellite, uncharacteristic of a discarded AKM. Reinforcing suspicions, on Friday, 18 January 2019, the subsatellite maneuvered eastward over

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

with the main TJS-3 satellite performing the same maneuver two days later. The two satellites continued to complete a number of synchronized maneuvers. Later in May 2019, capitalizing on the passing of the day-night terminator which makes satellite tracking by

optical telescope An optical telescope gathers and focus (optics), focuses light mainly from the visible spectrum, visible part of the electromagnetic spectrum, to create a magnification, magnified image for direct visual inspection, to make a photograph, or to co ...

impractical, the TJS-3 maneuvered far out of its orbit with its subsatellite taking its place shortly after. According to Jim Cooper, lead for space situational awareness for the space-tracking company COMSPOC, TJS-3 and its subsatellite were likely developing and validating tactics, techniques, and procedures (TTPs) for spoofing other nation's space situational awareness efforts which would mistake the subsatellite for its parent while the latter could "be off doing things that are potentially threatening". China has yet to acknowledge any secondary object associated with the TJS-3.

Satellites

References