China expands secretive satellite series with launch of TJS-15

HELSINKI — China launched the latest in a series classified satellites into geosynchronous transfer orbit Sunday while disclosing little about the spacecraft.

A Long March 3B rocket lifted off at 12:17 p.m. Eastern (1717 UTC) March 9 from the Xichang Satellite Launch Center, southwest China. The China Aerospace Science and Technology Corporation (CASC) announced launch success within an hour of liftoff. While the launch was anticipated due to airspace closure notices, the payload was unknown. CASC’s announcement revealed the mission payload to be communication technology experiment Satellite-15, or Tongxin Jishu Shiyan-15 (TJS-15).

CASC provided only a brief description of the TJS-15 satellite, without publishing images or technical information. “The satellite is mainly used to carry out multi-band, high-speed satellite communication technology verification,” the CASC statement read. 

The lack of details on the TJS-15 satellite is consistent with statements on earlier TJS missions. The series, which mostly operates in geostationary orbit (GEO), is seen by Western analysts as potentially carrying out classified missions including signals intelligence, early warning missions and satellite inspection activities to support the People’s Liberation Army (PLA).

TJS: Purposes and Molniya orbit mission

China launched its first TJS satellite in 2015. There are now 14 active satellites in series, with six TJS satellites launching over the past 18 months. The previous mission, TJS-14, launched in January, saw the spacecraft settle into the GEO belt at 18.3 degrees East, over Africa. 

Before this TJS-13, launched in December 2024, entered a highly elliptical, Molniya-like orbit, according to space domain awareness data from the U.S. Space Force. It joins two earlier-launched Chinese satellites, Shiyan-10 (01) and Shiyan-10 (02)—part of another series of satellites thought to be for testing new technologies and payloads—in similar orbits. A trio of satellites in such orbits can provide near-constant visibility over high latitudes for purposes including providing communications between two sites in the northern hemisphere or early warning monitoring.

Other notable TJS missions include TJS-3, launched in 2018, which released an object which carried out subsequent maneuvers. This indicates it was a subsatellite capable of coordinated movements with TJS-3. The main satellite later made close approaches to U.S. satellites.

Chinese launch activities in 2025

The launch of TJS-15 was China’s 10th orbital launch attempt of 2025. The next launch is expected to be a Long March 8 from the Hainan commercial spaceport March 11.

It is unclear as yet what number of launches China will be targeting for 2025. CASC, the country’s state-owned main space contractor, typically releases a “blue book” in January or February annually, detailing the previous year’s achievements and the main missions and targets for the year ahead. It has yet to do so publicly so far in 2025. 

Last year CASC stated that China aimed to launch around 100 times, with approximately 30 of these to be missions from commercial launch service providers. The country fell well short of this number, ending with 68 launch attempts with two failures. 

China this year aims to debut a series of new commercial rockets as well as the new Long March 8A and Long March 12A launchers. A highlight mission will be the Tianwen-2 near-Earth asteroid sample return and main belt comet rendezvous mission to launch around May. 

China plans to launch the crewed Shenzhou-20 and -21 missions to the Tiangong space station this year, with each mission expected to last around six months. The Tianzhou-9 cargo spacecraft will also be sent to the Tiangong space station this year, while a pair of new, smaller cargo spacecraft could also fly to Tiangong on new commercial rockets this year. 

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