Mysterious Chinese Satellite Reappears in Unexpected Orbit Following 6-Day Disappearance

Nearly a week after launch, space tracking systems were able to locate a mysterious satellite parked in an unusually low orbit. China launched the experimental satellite to test new technologies, but it’s still unclear exactly what it’s doing in its unique inclination.

Shiyan-28B 01 launched on July 3 from the Xichang Satellite Launch Center, riding on board a Long March 4C rocket. The satellite is part of China’s experimental Shiyan series, reportedly designed for exploration of the space environment and to test new technologies. It typically takes a day or two for space tracking systems to locate an object in orbit, but the recently launched Chinese satellite was hard to find.

The U.S. Space Force’s Space Domain Awareness unit was finally able to catalogue Shiyan-28B 01 on July 9, six days after its launch. The U.S. space monitoring system located the Chinese satellite in a 492 by 494 mile orbit (794 by 796 kilometer orbit) with an 11-degree inclination, astrophysicist Jonathan McDowell wrote on X. At the time of launch, it was estimated that the satellite would be tilted at a 35-degree inclination relative to Earth’s equator. Its unusually low inclination, however, suggests that the rocket performed a dogleg maneuver, meaning that it changed direction midway through ascent, and its second stage performed three burns to reduce inclination, according to McDowell.

It’s unclear why China performed the change in the rocket’s path after launch or what the purpose of the satellite’s low inclination is. China has never used such a low-inclination orbit before, according to SpaceNews. Based on its orbital inclination, the satellite will pass over parts of the South China Sea and the Indian Ocean, and it may be used for regional monitoring or communication tests.

China has been experimenting with new satellite technology. Two Chinese satellites recently performed a docking maneuver for an orbital refueling experiment, which has the potential to extend the lifespan of spacecraft in orbit. The country generally keeps the specifics of its experimental missions under wraps, carrying out secretive maneuvers in orbit as U.S. tracking systems do their best to keep watch.