On September 5, 2023, IFT was awarded an Air Force SBIR Phase I contract titled “Low SWAP-Cost Scalable and Resilient Onboard Cislunar PNT System”. This proposal introduces a unified approach for creating a low SWAP-Cost, scalable, and resilient OCPSA solution for cislunar PNT systems, beginning with the development of a cislunar PNT simulation tool. Through evaluations of various architectures and selecting four baseline CONOPS, a new operational concept will be devised, followed by the formulation of High Level Mandatory Requirements and the creation of a low SWAP-cost OPREX solution, while also investigating time synchronization methods and the potential of non-dedicated lunar assets for PNT services.