Modulating Retro-Reflectors: High-speed Asymmetric Laser Communications with Low-Fidelity Pointing Requirements (Phase II): Testing and Risk Reduction, Year 2

This is the second phase of a project that aims to advance a novel optical communication technology for spacecraft based on modulating retro-reflectors. Modulating retro-reflectors (MRR) are a potential communication alternative for small spacecraft. Retro-reflectors directly reflect a laser beam back to its source, regardless of its orientation. Using additional semiconductor technology, the return signal can be modulated, adding data transfer capability to the retro-reflector. A ground station would send up a laser beam to the spacecraft, and would receive high-speed data through the modulated return beam. The benefit of the system is that it utilizes the advantages of optical communication without imposing advanced attitude control requirements onto the spacecraft. The first phase of this project investigated the requirements for MRR communication on small spacecraft and tested capabilities of different MRR prototypes. In the second phase, we aim to make a selection of a protype technology and design, built and test an electrical circuit board that would enable usage of the device in a small spacecraft. Outcomes: We selected a Multiple Quantum Well (MQW) MRR for our prototype design. We developed, tested and documented a printed circuit board to integrate that MQW MRR into a cubesat. The circuit board follows the specication of NASA Ames PhoneSat bus to allow easy integration in to future cubesat missions for a technology demonstration. Interface control documentation is available on request. More »