Passive Communication Options for Miniature Satellites

Communication with miniature satellites presents a significant challenge, since their small size and limited power generation conflict with the need for long-distance communication links. Today's advanced sensors have driven the bar even higher byrequiring increased bandwidths that can only be satisfied by optical communication. Conventional free-space optical (FSO) communication, however, typically requires some form of mechanical beam steering, which is expensive, heavy and bulky, and can alsoupset the position of an orbiting satellite.We propose to develop a passive optical communication system that eliminates the need for tracking systems on the satellite. To accomplish this, we will make use of our Smart Retroreflector[TM], which can provide passive communication over an extremelywide field of regard. We will examine both conventional and MOEMS versions of this technology and will also investigate the use of optical gain media to amplify the communication signals. Hardware experiments will be performed to evaluate eachtechnique's feasibility, and the most effective technique will be chosen for further development and flight testing in Phase II. Our considerable laboratory experience and proven expertise in FSO communication place us in a unique position to address allrelevant issues for this program, from link performance to marketing strategies. In addition to the benefits of enabling low-cost satellites to be flown in great numbers, thereby advancing the state of science for space platforms, low-cost passive communication systems and components can be applied to a great number of applications.Just a few of the more prominent commercial, government, and operational military applications that could benefit from this and subsequent programs include truly high-speed, last-mile internet connectivity, Search and Rescue (SAR), robotic control,automated aircraft landing guidance, and auto-alignment of optical systems. The use of a low-power optical communicator will also enable accurate, covert combat identification to prevent