Mass concentrations ("mascons") perturb orbits of lunar satellites. The Lunar Orbiter is in a special "frozen" orbit in which the various perturbations cancel e

Mass concentrations ("mascons") perturb orbits of lunar satellites. The Lunar Orbiter is in a special "frozen" orbit in which the various perturbations cancel each other, with the tradeoff that this eccentric orbit is not optimal for photography. EDIT: The auto-generated transcript feature enables one to read enough to decide whether or not to watch the video.