Scientific Objectives and Engineering Constraints of Titan Landing Sites

The surface of Titan is highly diverse with a remarkable landscape including dunes, streambeds, and presently liquid-filled lakes, as well as mountain ridges, depressions, and rare, eroded impact structures. The geology is characterized by both smooth and rough surfaces with height variations (slopes) on short scales. Radar altimetry suggests the overall height variation is low, typically no more than 150 meters. However, occasional elevation changes of 500 meters have been discovered and Titan has mountains that sometimes reach several hundred meters to more than 1 kilometer in height. The process of identifying potential landing sites on Titan is based on the analyses of science cases, the definition of candidate sites, and engineering considerations. Regions for in-situ observations are the atmosphere, the surface, including both solid and liquid surfaces, and the subsurface. Concerning the surface solid areas as well as liquid zones must be considered. The most critical engineering constraints are atmospheric density and composition, temperature, surface hardness, roughness, inclination, sub-surface hardness, mechanical uniformity, composition, layering depths, and wind and seismic levels. The most promising sites are wet polar regions or dry equatorial regions because of their high compositional diversity and the mobility of material