Issue 135

TJS-21 Reaches HEO Orbit: Synchronized with SY-10 02

5 Dec 2025: As predicted in the 23 November 2025 Flash , China has placed its newly launched TJS-21 (66586) into a Highly Elliptical Orbit (HEO) and synchronized its orbit phase with Shiyan-10 02 (54878). The two satellites have a RAAN difference of ~180°, resulting in both satellites reaching their apogees at nearly…

5 Dec 2025: As predicted in the 23 November 2025 Flash, China has placed its newly launched TJS-21 (66586) into a Highly Elliptical Orbit (HEO) and synchronized its orbit phase with Shiyan-10 02 (54878). The two satellites have a RAAN difference of ~180°, resulting in both satellites reaching their apogees at nearly the same time. This configuration matches what China has done with TJS-13 (62188) and Shiyan-10 01 (49258). As a result China now has 24/7 dual satellite coverage of the northern high latitudes. Furthermore, screen captures from Chinese mission control during the TJS-13 launch (thank you Andrew Jones!) seem to show a missile warning satellite. Having two missile tracking satellites permanently perched over the northern hemisphere provides China with greater missile tracking accuracy and confidence levels. Combining with other open source information it now appears China has at least 3 GEO based missile warning satellites, TJS-2 (41911), TJS-5 (44978), and TJS-6 (47613) to go along with its 4 HEO satellites. By comparison the US Space Based Infrared System (SBIRS) consists of 6 GEO and 4 HEO satellites.