These are extremely stable points, as demonstrated by the clusters of asteroids found there. The supplies from the Moon, added to these asteroids, were used to first build wheel-type stations, then, later, the larger O'Neill islands and cylinder colonies. By 2210, most of the colonies in existence are O'Neill-type cylinders, with the exception of the Jovian ones, which had to be build on the closed Vivarium model because of the increased radiation levels. They are huge cylinders varying between 25 and 40 km in length, usually with thrusters and zero-gee docking bays at both ends. Each is home to up to 20 million people, though smaller ones are not uncommon.
Gravity is simulated by rotation along the axis of the cylinder.
Originally no larger than a man, they increased in size until some of the biggest were nothing less than small ships. This was necessary in order to carry the enormous amount of fuel, armament, and electronics necessary to accomplish their assigned mission. The linear frame is the main control element of the exo-armor. The exo-armor's onboard drive computer then interprets these motions and moves the armor's limbs accordingly, firing apogee motors as needed to compensate. The linear frame control system gives the exo-armor an uncanny maneuverability as well as a strangely human grace.