China launched four Earth-observation satellites from the Taiyuan Satellite Launch Center in Shanxi province on Thursday afternoon.

The group consists of one 320-kilogram pivot satellite and three 270-kg assistant satellites, and are the first space-based assets in the Hongtu 1 network. The satellites were sent into space by a Long March 2D carrier rocket that blasted off at 6:50 pm.

Developed by GalaxySpace, a Beijing-based private satellite maker, each of the satellites carries an interferometric synthetic aperture radar.

The spacecraft will form a wheel-shaped network, as the three assistant satellites move around the pivot satellite as all travel in orbit.

This will be the first time any satellites will form a wheel-shaped system, according to GalaxySpace.