Autonomous Landing and Hazard Avoidance Technology (ALHAT)

The ALHAT project is funded by NASA to develop an integrated AGNC (autonomous guidance, navigation and control) hardware and software system capable of detecting and avoiding surface hazards and guiding humans and cargo safely, precisely and repeatedly to designated lunar landing sites. There are important interdependencies driving the design of a lunar landing system including such things as lander hazard robustness, landing site conditions (terrain and natural lighting), trajectories, sensors, crew involvement, and others. The ALHAT system must be capable of operating in a wide range of lunar environments and supporting global lunar access for both crewed and robotic missions. This paper discusses the major factors driving the design of a lunar landing system as well as the current state of the technology development. The supporting analysis and testing results will be presented that show the system interdependencies and their relative importance, as well as the trades needed to optimize the landing system. The emphasis is on the final phase of the landing where hazard detection and avoidance (HDA) and hazard relative navigation (HRN) are the primary considerations in achieving a safe landing. The current sensor options being considered and the status of the development of those sensors are discussed.