Beijing has placed a classified spacecraft in an orbit never seen before, giving it the ability to survey every satellite parked in the geostationary belt without burning propellant.
A fresh orbit for an old trick
The Shijian-31 satellite rode a Long March 3B out of Xichang on June 16. Chinese authorities called it a routine space environment monitoring payload, but independent trackers immediately spotted something else. The spacecraft settled into a modified Molniya orbit a highly elliptical path normally reserved for Arctic communications and missile early warning. Instead of lingering over the northern hemisphere as those satellites do, Shijian-31 points its apogee at the equator.
From roughly 39,900 kilometers up, the satellite drifts 15.7 degrees in longitude on each 12.5-hour pass. The full GEO belt scrolls beneath it once every 23 days at zero fuel cost.
Watching the neighborhood
Integrity ISR detected the anomaly June 26, and ComSpOC followed July 21 with a post calling it a satellite with an orbit we have never seen before. The spacecraft stays too high for conventional remote sensing satellites to get a clear look its perigee sits at roughly 2,000 kilometers. But a modest 50-meter-per-second burn at perigee could slide Shijian-31 straight into the GEO neighborhood, Integrity ISR noted.
The payload belongs to China’s Shijian family, a catch-all designation for experimental satellites that has previously covered on-orbit refueling tests and space situational awareness work. CASC released no imagery of the craft and offered only the generic space environment exploration label given to most classified missions in the line.
Secure World Foundation’s Victoria Samson described the profile as pretty unusual and difficult to assess with the sparse data available so far. Analysts expect more clues about Shijian-31’s real mission to emerge as weeks of orbital behavior accumulate.
