SAIC is seeking an Information Systems Security Officer (ISSO) to provide critical cybersecurity governance, compliance, and security oversight support on SAIC’s prime program, Landmark AOS, located in Chantilly, VA. Landmark AOS is a large SETA program supporting the NRO’s Ground Enterprise Directorate (GED), responsible for the acquisition and sustainment of systems across the full end‑to‑end lifecycle. As an ISSO, you will play a key role in ensuring customer systems maintain compliance with Federal, Agency, and IC security requirements. You will oversee the security posture of customer‑sponsored assets, guide programs through the Risk Management Framework (RMF), and provide continuous monitoring, authorization, and cybersecurity risk support across multiple mission partners.