Patent ID: 7967255

Claim:
An autonomous planetary lander, comprising: a soft landing impact attenuation system, a payload module; a bi-propellant propulsion module including fuel tanks for storing propellant and a set of nozzles that expel the propellant to perform velocity braking and lateral divert maneuvers, said propulsion module providing a thrust-to-mass (T/M) ratio of between 15:1 and 100:1 per nozzle, said lander having a fuel mass fraction (FMF) of less than 40% of the landed dry mass of the lander; and an avionics module including, a navigation subsystem including at least one sensor that gathers terrain data and a terrain image correlator that correlates the gathered terrain data to reference maps to provide a navigation update; and a guidance subsystem that processes the navigation update to estimate cross-track and along-track navigation errors with respect to a specified landing site designated in the reference map and issues discrete pulse-width modulation command signals to the propulsion module to perform at least one lateral divert maneuver while the lander is coasting to reduce the cross-track navigation error and to perform at least one velocity braking maneuver with approximately 3-15 seconds to touchdown to remove the lander velocity and reduce the along-track navigation error so that the lander lands softly on the landing attenuation system within 1 km of the specified landing site, wherein the FMF to perform the velocity braking maneuver is at most 24%.