In a satellite constellation forming system, each satellite in an orbit satellite group includes a propulsion device to change velocity of each satellite in the orbit satellite group. A satellite constellation forming unit causes propulsion devices of satellites in the orbit satellite group to operate in synchronization, for each orbital plane of the plurality of orbital planes. The satellite constellation forming unit causes each satellite in an orbit satellite group in a first orbital plane of the plurality of orbital planes to perform an acceleration and deceleration process of repeating operation of accelerating for a first time period and then decelerating for the first time period. The satellite constellation forming unit causes each satellite in an orbit satellite group in an orbital plane adjacent to the first orbital plane to start the acceleration and deceleration process after a delay of a second time period.