China has successfully deployed the world's first three-satellite constellation on the distant retrograde orbit (DRO) of the Earth-Moon system, marking a milestone in the country's deep-space exploration capabilities, scientists announced at an academic symposium in Beijing on Monday.
A distant retrograde orbit (DRO), as most commonly conceived, is a spacecraft or it around a moon that is highly stable because of its interactions with two Lagrange points of the planet–moon system.
https://en.m.wikipedia.org/wiki/Distant_retrograde_orbit