Michigan Aerospace Corporation has developed spaceflight qualified compact tunable Fabry-Perot interferometers for a number of applications, from ranging direct detection Doppler wind LIDAR applications to IR spectroscopy. Under a previous phase I SBIR, Michigan Aerospace developed a design for a spaceflight qualified lightweight tunable Fabry-Perot etalon for cryogenic applications utilizing reaction bonded silicon carbide for the etalon mount and support rings and successfully delivered a mount and rings cast from silicon carbide for use in a phase II, or another application, to house an etalon. Under the proposed phase II effort, Michigan Aerospace will develop and fabricated a lightweight, rugged tunable Fabry-Perot interferometer that will be spaceflight qualified. Also, under this proposed phase II effort, Michigan Aerospace will design and produce a digital etalon controller. Further, Michigan Aerospace will produce a detailed plan by which the digital etalon controller design can be transitioned from demonstration unit to flight qualified hardware.