The U.S. Space Force (USSF) Operation Test and Training Infrastructure (OTTI) Program Executive Office (PEO) is releasing a series of Department of Air Force (DAF) Architecture documents to provide industry with awareness and facilitate informed planning for future opportunities. These documents outline the architectural framework for the OTTI program and were developed to directly address the requirements outlined in the OTTI System Requirement Documents (SRDs). Industry stakeholders are encouraged to review these documents and provide feedback on the proposed technical direction. These preliminary documents represent our current thinking, and we consider industry input a critical component for maturing the program's architecture. As the OTTI program matures and requirements evolve, these documents will be updated and revised. Revised versions will be posted to this Sam.gov opportunity notice.