Attitude Control System for Laser Lightcraft

Reducing the cost of launching payloads into low earth orbit by a factor of 10 or 100 requires revolutionary changes in launching architectures. The Laser Lightcraft holds the potential for such savings by placing the bulk of the propulsion system on theground by using a ground-based laser to provide the impulse for lifting the payload. Attitude control for the Lightcraft is critical. This Phase II proposal briefly reviews the work performed in the Phase I effort which included the design of theattitude control system and the diffractive optic concept that is critical to achieving the necessary control of the Lightcraft.The proposed concept consists of a diffractive optic to appropriately shape the beam for providing lateral stability. An attitude control system that consists of a vision system, control point light sources on the craft, and a tip / tilt mirror is used todynamically adjust the beam to account for atmospheric turbulence and wind that cause the craft to exit the beam. A six degree-of-freedom model developed under the Phase I effort will be expanded and updated to include the latest performancecharacteristics and each of the components in the proposed system.