Optical communications development for spacecraft applications: Recent progress at JHU/APL

Free-space optical communication systems for deep space as well as near terrestrial space environments are now under development for deployment aboard spacecraft within the next few years. Ever-increasing requirements for high data-rate communications are driving significant investments by NASA and DoD in critical technology readiness for spaceflight. One of the key NASA requirements is science data retrieval at rates much higher than heretofore possible with RF systems, for missions as far out as interstellar space and as close as geosynchronous earth orbit (GEO). Recent efforts at Johns Hopkins University Applied Physics Laboratory (JHU/APL) are summarized that are focused on these requirements and challenges. We are developing a spacecraft optical communications terminal architecture initially using commercial off-the-shelf components while accelerating the development of state-of-the-art replacement components, which minimize mass and prime power while maintaining or improving performance. Recent technology development efforts will be summarized that include pulse position (PPM) modulator/demodulator chip development, compact optical beamsteerering technology, including micro-electromechanical systems (MEMS), an ultra-lightweight deployable dual-band antenna concept, and a low-mass low-power optical downlink terminal design intended for deployment on a realistic interstellar explorer (RISE) mission.