A Compact Laser Altimeter for Spacecraft Landing Applications

APL has developed a compact laser altimeter capability to enable small spacecraft missions to rendezvous with low-gravity planetary bodies, such as asteroids, comets, and moons. Precision range data have been shown to significantly improve spacecraft control in close-approach and landing scenarios, and not surprisingly, the data are most critical in the final descent phase where the spacecraft is within a few kilometers to a few meters from the target surface. These missions require both improved precision from previously flown lidar technologies as well as much reduced size, weight, and power given the resource-constrained class of missions likely to use this capability. API has been pursuing a prototype laser altimeter that achieves the desired ranging accuracy and precision while requiring minimal resources from the spacecraft bus.