Senior ISSO – RMF/Zero Trust Security Lead

Celestar Corporation; Washington (District of Columbia); On-site; USD 125,000 - 200,000; Full time

Job summary

Celestar Corporation seeks a Senior Information Systems Security Officer (ISSO) to lead cybersecurity and RMF activities for critical systems. You will coordinate with engineers, operators, and government stakeholders to maintain Authority to Operate (ATO) and ensure ongoing compliance across the system lifecycle.

The role requires active TS/SCI with polygraph, Security+ or equivalent, and 18+ years in cybersecurity, with hands-on RMF, IATT/ATO experience, and proficiency in XACTA and Splunk.

Qualifications

• Active TS/SCI with polygraph
• Security+ or equivalent DoD IAT II/III
• 18+ years in cybersecurity or related field
• Experience as ISSO/ISSE or similar
• Experience coordinating RMF activities and ATO processes
• Proficiency with XACTA for RMF documentation
• Experience with RMF and IATT/ATO
• Strong communication with stakeholders
• Experience implementing NIST 800-53 controls

Responsibilities

• Lead cybersecurity and compliance for mission-critical systems
• Ensure security compliance and support authorization activities
• Coordinate with engineers, operations, and government stakeholders
• Develop and maintain SSPs, SAPs, POA&Ms, and artifacts
• Support security assessments and remediation efforts
• Implement Zero Trust across enterprise and cloud environments
• Manage risk findings, mitigation, and compliance tracking
• Utilize Splunk for security monitoring and reporting
• Coordinate with ISSMs, ISSEs, System Owners, and AOs

Skills

Active TS/SCI with Polygraph

Security+ / DoD IAT II/III

XACTA RMF

Splunk

ISSO / ISSE experience

Security controls (NIST 800-53)

Education

Bachelor's degree in Cybersecurity or related

Master's degree may substitute for 6 years

Tools

XACTA

Splunk

Job description

Celestar Corporation seeks a Senior Information Systems Security Officer (ISSO) to lead cybersecurity and RMF activities for critical systems. You will coordinate with engineers, operators, and government stakeholders to maintain Authority to Operate (ATO) and ensure ongoing compliance across the system lifecycle.

The role requires active TS/SCI with polygraph, Security+ or equivalent, and 18+ years in cybersecurity, with hands-on RMF, IATT/ATO experience, and proficiency in XACTA and Splunk.