The Creation and Simulation of a Risley Prism Assembly

Intentions of humans revisiting the moon, exploring new planets, and the ever sought out goal of landing humans on Mars is a focus for NASA. With the most recent human missions being the Apollo missions in the 1960's-1970's, upgrades to previous landers are a continuing project. One of the most important and difficult parts of these missions is the landing. An unknown environment and terrain provide challenges for the crew or lander, that may result in broken instruments, overuse of fuel and worst of all, loss of life. The following paper highlights the work done to build a demo lidar scanner for landers and other spacecrafts that touchdown on an alien surface. This instrument intends to provide key information about the surface by creating a three-dimensional map of the terrain in a couple of seconds. Information that can then be used as feedback to the guidance computer and pilots to make an informed decision about a safe landing site. The work is being undertaking by a team at Goddard Spaceflight Center under the electro-mechanical systems branch, and the following represents the work done to create a prototype scanner.