GPS Subject Matter Expert (Enterprise PNT Systems SME)

GPS Subject Matter Expert (Enterprise PNT Systems SME) Job Locations US-CA-El Segundo ID 2026-1930 Category Systems Engineer Required Security Clearance TS/SCI (SSBI) Type Full-Time Overview Stellar Solutions, a nationally recognized "Great Place To Work", has exciting opportunities providing Engineering solutions for innovative new-entrant space companies, as well as established space systems manufacturers, commercial space system operators and service providers, and other industry stakeholders including investors. At Stellar Solutions, we offer talented, energetic, and immediately productive resources to satisfy our customers' critical needs in systems engineering and integration, mission operations, program management and strategic planning. We are a leading service and expertise provider for high-tech commercial ventures, spanning communications, earth observation and remote sensing systems and data products, to the infrastructures that support earth orbiting and beyond earth orbit businesses. Role/Responsibilities/Qualifications Stellar Solutions is seeking a GPS Subject Matter Expert (SME) to support enterprise-level modernization of the Global Positioning System (GPS) for the U.S. Space Force. This role will provide deep technical expertise across the GPS space, ground, and user segments, supporting integration and evolution of the GPS III and GPS III Follow-On (GPS IIIF) constellation as the system transitions to the modernized Next Generation Operational Control System (OCX). The candidate will advise government and contractor teams on Positioning, Navigation, and Timing (PNT) architecture, modernization initiatives, and the integration of new GPS capabilities such as M-Code, L1C interoperability, and Regional Military Protection (RMP). GPS Enterprise Systems Expertise Provide subject matter expertise across the GPS enterprise architecture including the space segment (GPS III / GPS IIIF satellites), control segment (OCX ground system), and user segment (military and civil GPS receivers). GPS III / GPS IIIF Modernization Support Support integration of next-generation GPS capabilities including M-Code military signal deployment, L1C interoperability with international GNSS systems, Regional Military Protection (RMP) spot beam capability, satellite navigation payload enhancements, and laser retroreflector arrays. Positioning, Navigation, and Timing Architecture Support development and analysis of enterprise PNT architecture including resilient PNT strategies for contested environments, multi-GNSS interoperability, augmentation systems, and timing synchronization dependencies across critical infrastructure. Systems Engineering and Integration Support system-of-systems integration across GPS enterprise components including requirements definition, architecture documentation, Interface Control Documents (ICDs), technical baseline management, and systems engineering reviews (SRR, PDR, CDR). Acquisition and Program Support Provide advisory support to government program offices including technical evaluation of contractor designs, acquisition planning support, risk identification and mitigation, and participation in program milestone reviews. Required Qualifications 10+ years experience in GPS or satellite navigation systems Experience with Positioning, Navigation, and Timing (PNT) technologies Knowledge of GPS space, ground, and user segment Systems engineering experience across space or defense program Familiarity with DoD acquisition lifecycle and space program Bachelor's degree in Engineering, Physics, Mathematics, or related field Ability to obtain or maintain a DoD security clearance Desired Qualifications Experience supporting Space Systems Command (SSC) or Space Operations Command Knowledge of GPS III / GPS IIIF program Experience with M-Code or NAVWAR technologie Experience with OCX ground system Familiarity with GNSS interoperability (Galileo, etc.) Master's degree in Engineering or related field Clearance Required Active Secret or Top Secret Clearance Location This position is expected to be on site in El Segundo, CA and will require travel up to 25% of time within the continental United States Compensation The typical salary range for this position is USD $160,000 - $190,000 per year. Individual pay is determined by many factors including work location, job-related skills, experience, and relevant education or training. This position is also eligible for a discretionary annual performance bonus, retirement plan and other benefits (all in addition to annual salary). Deliverable(s) Deliverables will be in the format of reports, briefings, spreadsheets, or other documents as directed by the Government, using government approved and/or mandated systems/software and processes governed by guidance/instructions/policy or direction.