Mission Security Engineer

Apex manufactures satellite buses at scale. The Mission Security Engineer will own or contribute to the authorization posture of a space vehicle and a classified cloud mission operations environment, producing RMF authorization documentation, building authorization packages, managing POA&M, and running continuous monitoring. This role involves cyber engineering for mission systems, not traditional IT security.

Required: U.S. Citizenship, active Top Secret clearance with SCI access and SAP eligibility preferred, experience with technical tooling. Entry level: bachelor's in systems engineering, computer science, cybersecurity, aerospace, or related field, hands-on building experience, willingness to learn RMF. Senior level: strong experience in embedded/space systems or cloud infrastructure, multiple systems taken to authorization in national security or DoD environments.