A method of navigating a space vehicle. An image of a planet surface is
received. The received image is processed to identify edge pixels and
angle data. The edge pixels and angle data are used to identify planetary
features by shape, size, and spacing relative to other planetary
features. At least some of the planetary features are compared with a
predefined planet surface description including sizes and locations of
planet landmarks. One or more matches are determined between the
planetary feature(s) and the planet surface description. Based on the
match(es), a location of the space vehicle relative to the planet is
determined.