PIESAT 1B-01, 02, 03 (Hongtu-1 1B-01, 02, 03)

PIESAT 1B [Galaxy Space]

PIESAT is a Chinese interferometric synthetic aperture radar (InSAR) earth observation constellation built by Galaxy Space consisting of active and passive X-band SAR satellites.

This mission's four satellites, which consist of a master satellite (PIESAT 1A) and three auxiliary satellites (PIESAT 1B), are the first four-satellite X-band InSAR Earth imaging system in existence. According to GalaxySpace, the company that created the satellites, the master satellite weighs roughly 320 kilograms, while a single assistant satellite weighs roughly 270 kilograms.

With the master satellite in the center and the three assistant satellites distributed evenly on the hub, these satellites in orbit also make up the first wheel-pattern satellite formation in the history of the planet. The formation uses phase synchronization and inter-satellite communication links to enable accurate orbit control, ensuring its stability and spatial safety.

According to GalaxySpace the wheel-pattern formation, in comparison to conventional interferometric satellite systems, has the advantages of a relatively stable formation configuration, multiple interference baselines, and high mapping efficiency. These satellites' millimeter-level deformation monitoring capability, which can provide data support for the investigation and prevention of land subsidence, collapse, landslides, and other disasters, makes them a powerful tool for early identification of major geological hazards in complex areas.