?????: Reports

China’s SJ-31 Satellite In Position to Monitor GEO from an Unusual Highly Elliptical Orbit (HEO)

Written by Greg Gillinger On 16 June 2026, China launched a Long March 3B/E from Xichang carrying Shijian-31 (SJ-31) (69570). Initial TLE data from SpaceTrack indicates the satellite is operating in a highly elliptical orbit (HEO) with an inclination of approximately 63.4° and an eccentricity of 0.69—consistent with a Molniya-type orbit. The satellite has an orbital period of approximately 12.5 hours, completing just under two orbits per day. China has released little information on SJ-31, stating only that it will be used for “space environment detection.” Molniya orbits take advantage of Earth’s oblateness (J2 perturbation) at the critical inclination of approximately 63.4° to stabilize the Argument of Perigee over time. […]