Saturn’s moon Titan is the richest laboratory in the solar system for studying prebiotic chemistry, which makes studying its chemistry from the atmosphere to the surface one of the most important objectives in planetary science. Landing dispersions with current technology are hundreds of kilometers wide, precluding safe landing anywhere except the large northern seas and featureless plains. By far the greatest contribution to lander delivery error in past Titan missions has been long parachute descent phases (~ 2.5 hours) from high altitudes (~ 150 km) in high winds with large wind uncertainties; therefore, addressing error during parachute descent is the key to enabling precision landing. Titan’s dense atmosphere and low gravity potentially make guided parachutes or parafoils attractive approaches to achieve large diverts at comparatively low cost; however, such systems have never been used on another planetary body. Position estimation during descent has unique difficulties, because the hazy atmosphere prevents acquiring imagery from orbit with the very high resolution (30 cm/pixel) possible for Mars, where precise navigation for descent can be achieved by real-time matching of descent imagery to high-resolution orbital imagery. This task is addressing the problems of descent navigation and is developing performance models for guided parafoils in the Titan environment.
Larry Matthies - Jet Propulsion Laboratory
NASA Space Exploration Technology Directorate (STMD)