Information Systems Security Officer; ISSO- Senior

We are seeking a dedicated Senior Information System Security Officer (ISSO) to provide cybersecurity expertise for a vital Department of Defense (DoD) initiative focused on space-based operations and national security. The ISSO will support the development, implementation, and maintenance of the cybersecurity program to ensure compliance with DoD security requirements and the Risk Management Framework (RMF). This role will involve working closely with multidisciplinary teams to protect critical systems and ensure mission success.

• Implement and maintain cybersecurity controls for mission systems to protect sensitive data and assets.
• Assist in the development and maintenance of System Security Plans (SSPs), Risk Assessment Reports (RARs), and other RMF documentation.
• Ensure compliance with DoD regulations, policies, and guidance, such as STIGs, FISMA, and NIST SP 800-53.

• Support the RMF process, including categorization, control selection, assessment, and continuous monitoring of system security posture.
• Assist in the preparation and submission of Authorization to Operate (ATO) packages and ensure systems maintain their authorized status.
• Collaborate with engineering and operational teams to implement required security controls and resolve deficiencies.

• Conduct security audits, scans, and continuous monitoring to validate compliance and identify vulnerabilities.
• Maintain logs, reports, and documentation related to system access, security incidents, and cybersecurity status.
• Prepare briefings and reports for program managers and stakeholders regarding cybersecurity performance and risks.

• Monitor systems for security incidents, conduct initial investigations, and assist in handling and reporting incidents according to DoD protocols.
• Develop and implement plans to mitigate identified vulnerabilities and reduce risks to the systems.

• Liaise with Information System Security Managers (ISSMs), program leadership, and engineering teams to ensure cybersecurity objectives are met.
• Support cross-functional teams to align cybersecurity efforts with mission requirements.

• Ensure personnel are trained and aware of cybersecurity responsibilities, policies, and best practices relevant to the systems.

• Bachelor's degree in Cybersecurity, Information Assurance, Computer Science, or related technical field.
• 10+ years experience in information systems security or related roles within DoD environments.
• Knowledge of RMF processes, DoD cybersecurity standards, and NIST 800-53 control frameworks.
• Familiarity with security tools such as ACAS, Nessus, Splunk, or SIEM platforms.
• Strong problem‑solving and analytical skills with attention to detail in a compliance‑driven environment.
• Excellent communication skills for collaboration with technical teams and program managers.

• Certifications such as Security+, CEH, CISSP, or other DoD‑approved cybersecurity certifications.
• Experience with space‑based systems or satellite communications cybersecurity.
• Familiarity with implementing and maintaining security controls for classified and unclassified systems.

• Active TOP SECRET (TS) clearance with eligibility for Sensitive Compartmentalized Information (SCI).
• U.S. Citizenship is required for this position.

MTSI embraces nine core values including our first core value of Employees come first. Consistent with our Core Values, we are committed to Equal Opportunity, making decisions without regard to race, color, religion, sex, national origin, age, military/veteran status, disability, or any other characteristics protected by applicable law. MTSI is committed to Equal Employment Opportunity and providing reasonable accommodations to applicants and employees with physical and/or mental disabilities.

Modern Technology Solutions, Inc. (MTSI) is a 100% employee‑owned engineering services and solutions company that provides high‑demand technical expertise in Digital Transformation, Modeling and Simulation, Rapid Capability Development, Test and Evaluation, Artificial Intelligence, Autonomy, Cybersecurity and Mission Assurance.

MTSI delivers capabilities to solve problems of global importance. Founded in 1993, MTSI today has employees at over 20 offices and field sites worldwide.

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