York is seeking a highly experienced Senior Information Systems Security Manager (ISSM) to lead cybersecurity governance, compliance, and risk management activities across our ground systems and space vehicle programs. This role is central to safeguarding mission‑critical assets, overseeing enterprise security authorizations, and ensuring full compliance with Department of War (DoW) and Intelligence Community (IC) cybersecurity standards.   The Senior ISSM will manage a multidisciplinary team of networking and cybersecurity professionals, providing strategic leadership across the entire Risk Management Framework (RMF) lifecycle. This position is responsible for the development, sustainment, and future evolution of Authority to Operate (ATO) packages supporting multiple classified environments. Close partnership with engineering, operations, and program leadership is essential to ensure security controls are correctly implemented, rigorously tested, accurately documented, and fully compliant with all mission and regulatory requirements.   This role will be fully on-site in our Greenwood Village, Colorado office.    Responsibilities Serve as the primary cybersecurity authority for ground and space-based systems throughout development, deployment, and operations. Lead the creation, implementation, and maintenance of RMF packages in alignment with DoD, NIST SP 800-53, and DAAPM requirements. Manage and sustain ATOs, including reauthorization efforts and updates driven by system modifications or evolving mission needs. Provide direct leadership, mentorship, and oversight to a team of cybersecurity and IT professionals, ensuring excellence in both technical execution and compliance. Act as a central liaison between internal engineering teams, external assessors, and government accrediting officials. Conduct comprehensive risk assessments, vulnerability analyses, and POA&M management across legacy, current, and emerging systems. Maintain strict adherence to configuration management and change control processes. Support incident response readiness, audit preparation, and continuous monitoring activities. Promote cybersecurity awareness and reinforce policy compliance across engineering, operations, and leadership organizations.   This role will have direct reports.   Required Qualifications Bachelor’s degree required.   8+ years of relevant experience in Information Assurance or Cybersecurity, Expert-level understanding of the Risk Management Framework (RMF), NIST SP 800-53 controls, and applicable federal cybersecurity regulations. Proven success leading ATO efforts for classified systems. Strong technical foundation in network and system security with the ability to effectively guide and influence a multi-disciplinary technical team. U.S. Citizenship. Active TS/SCI clearance. Willingness to work full-time in office in Greenwood Village, CO.   Preferred Qualifications Master’s degree. Professional certification such as CISSP or CISM. Experience with space systems, ground segments, or defense-related programs. Familiarity with eMASS. Knowledge of cross-domain solutions, encryption key management, and COMSEC principles. Experience collaborating with the Defense Counterintelligence and Security Agency (DCSA), SDA, or other defense and intelligence security organizations.