The availability of small, low power atomic clocks is now a reality for ground-based and airborne navigation systems. Kernco's Low Power Precision Time Source (LPPTS) is based on Coherent Population Trapping (CPT) technology. Several of these units were recently delivered to the Air Force Research Laboratory (AFRL) at Kirtland Air Force Base and have demonstrated the performance and robustness of the matured design. Since CPT technology has been demonstrated as a viable solution to providing low-power, high-performance atomic clocks, it makes sense to explore the potential for deploying these units for space operations. Size, Weight and Power (SWAP) rank among the highest of the critical parameters in the design and fabrication process of a satellite system. However, the single most critical parameter is perhaps the radiation tolerance of any electronic system. By using the LPPTS design as a point of departure, Kernco proposes to implement a radiation tolerant design of its CPT-Based Atomic Clock to satisfy the need for Low Cost, High Accuracy Timing Signals for small satellite flight opportunities. This SBIR Phase I proposal will focus on the design of a Radiation Tolerant Low Power Precision Time Source (LPPTS-R) suitable for integration into the Space Plug-and-Play Architecture (SPA).