Missions frequently depend on distributed teams, instrument builders at universities, science operations centers, and international partners, connected by data portals, shared repositories, and federated credentials. A compromise of a collaborator yields access to telescience networks, analysis pipelines, instrument commanding tools, and file exchanges that deliver ephemerides, calibration products, procedures, or configuration tables into mission workflows. Partners may operate their own ground elements or payload gateways under delegated authority, creating additional entry points whose authentication and logging differ from the prime’s. Initial access emerges when attacker-modified artifacts or commands traverse these sanctioned paths: a revised calibration script uploaded through a science portal, a configuration table promoted by a cross-org CI job, or a payload task submitted via a collaboration queue and forwarded by the prime as routine work. Variations in process rigor, identity proofing, and toolchains across institutions amplify the attacker’s options while preserving the appearance of legitimate partner activity.
| ID | Name | Tiering | Description | NIST Rev5 | ISO 27001 | Onboard SV | Ground | |
| CM0022 | Criticality Analysis | Criticality analysis is a structured engineering process that identifies the mission functions, system components, and data flows whose compromise, degradation, or loss would most severely impact mission success, crew safety, or operational continuity. The outputs of this analysis directly drive security investment prioritization: components and functions assessed as most critical receive the most rigorous design-phase protections, supply chain scrutiny, and operational security controls, while lower-criticality elements are protected proportionately. Criticality analysis findings should inform the application of complementary security design principles, including network and functional segmentation and least-privilege access control, to isolate critical components from less-trusted system elements and reduce the consequence of compromise elsewhere in the system. Supply chain protection resources and oversight rigor should be explicitly allocated in proportion to component criticality, ensuring that the most mission-essential hardware and software receive the most intensive sourcing controls, provenance verification, and supplier oversight. Criticality analysis must be initiated early in the system design process and updated as the architecture evolves, threat intelligence changes, or operational experience reveals previously unrecognized dependencies. | CM-4 CP-2 CP-2(8) PL-7 PL-8 PL-8(1) PM-11 PM-17 PM-30 PM-30(1) PM-32 RA-3 RA-3(1) RA-9 SA-11 SA-11(3) SA-15(3) SA-2 SA-3 SA-4(5) SA-4(9) SA-8 SA-8(25) SA-8(3) SA-8(30) SC-32(1) SC-7(29) SR-1 SR-2 SR-2(1) SR-3 SR-3(2) SR-3(3) SR-5(1) SR-7 | A.8.9 7.5.1 7.5.2 7.5.3 A.5.2 A.5.29 A.8.1 A.5.30 8.1 A.5.8 A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 6.1.2 8.2 9.3.2 A.8.8 A.5.22 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.8.29 A.8.30 5.2 5.3 7.5.1 7.5.2 7.5.3 A.5.1 A.5.2 A.5.4 A.5.19 A.5.31 A.5.36 A.5.37 A.5.19 A.5.20 A.5.21 A.8.30 A.5.20 A.5.21 A.5.22 | ||||
| CM0039 | Least Privilege | The principle of least privilege requires that every process, user account, service, and system component be granted only the permissions and access rights necessary to perform its defined function, with no additional privileges retained beyond what the assigned task requires. Applied to spacecraft and ground systems, this means that processes executing on flight computers, operating system services, ground system applications, and inter-system communication handlers are each confined to the minimum privilege level needed for their specific function, preventing a compromised or malfunctioning component from leveraging excess permissions to affect other system resources or functions. Separate execution domains should be used where supported to reinforce least privilege and contain process failures or compromise. Process isolation does not replace explicit access controls, because authorized communication and shared resources may still cross execution-domain boundaries. Least privilege is a foundational design principle that reduces the consequence of any individual component compromise by limiting what an adversary can accomplish within that component's execution context. | AC-2 AC-3(13) AC-3(15) AC-4(2) AC-6 CA-3(6) CM-7 CM-7(5) CM-7(8) PL-8 PL-8(1) SA-17(7) SA-3 SA-4(9) SA-8 SA-8(13) SA-8(14) SA-8(15) SA-8(19) SA-8(3) SA-8(4) SA-8(9) SC-2(2) SC-32(1) SC-49 SC-50 SC-7(29) | A.5.16 A.5.18 A.8.2 A.5.15 A.8.2 A.8.18 A.8.19 A.8.19 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 | ||||
| CM0005 | Ground-based Countermeasures | Ground-based countermeasures protect the terrestrial capabilities that develop, launch, command, monitor, operate, secure, and sustain space missions. These capabilities may be distributed across mission-owned systems, contractor environments, external partners, and commercial service providers. Because ground segment architectures and responsibilities vary, cybersecurity protections should be selected through threat-informed analysis of the mission functions being performed rather than through indiscriminate application of a single control set. The SPARTA Ground Segment Cyber Defenses guidance provides an interactive functional decomposition that maps ground segment function groups to applicable Defense-in-Depth sub-layers and countermeasure targets. The supporting report, VTR-2026-00702 Rev A, Ground Segment Cyber Defenses and Risk-Based Tiering, provides the methodology, definitions, and risk-tier rationale. The accompanying Ground Segment Cyber Defenses Excel Workbook consolidates the function mappings and Baseline and Enhanced countermeasure guidance into a resource that can be tailored to a specific mission architecture. | SPARTA Ground Segment Cyber Defenses guidance | None | ||||
| CM0038 | Segmentation | Segmentation establishes physical or logical isolation boundaries between spacecraft system components and functional domains to limit the propagation of compromise, contain the consequences of a security failure, and enforce controlled information flow across the mission architecture. Mission-critical functions must be isolated from non-mission-critical functions through enforced partition boundaries that control access to and protect the integrity of the hardware, software, and firmware implementing those functions. Information flow between partitioned components or applications must be explicitly authorized by security policy; any flow not affirmatively permitted is denied by default. Boundary protections must be implemented to separate spacecraft bus, communications, and payload components, preventing a compromise in one domain from directly affecting the others. Information crossing the spacecraft boundary shall receive confidentiality protection where required by its classification, sensitivity, or mission risk. Command-bearing and other security-critical exchanges shall receive the mission-required authentication, integrity, authorization, and anti-replay protections regardless of whether confidentiality is required. These controls collectively implement a defense-in-depth architecture in which an adversary who gains a foothold in one partition faces enforced barriers before reaching mission-critical assets. | AC-4 AC-4(14) AC-4(2) AC-4(24) AC-4(26) AC-4(31) AC-4(32) AC-4(6) AC-6 CA-3 CA-3(7) PL-8 PL-8(1) SA-3 SA-8 SA-8(13) SA-8(15) SA-8(18) SA-8(3) SA-8(4) SA-8(9) SC-16(3) SC-2(2) SC-3 SC-3(4) SC-32 SC-32(1) SC-39 SC-4 SC-49 SC-50 SC-6 SC-7(20) SC-7(21) SC-7(29) SC-7(5) SI-17 SI-4(7) | A.5.14 A.8.22 A.8.23 A.5.15 A.8.2 A.8.18 A.5.14 A.8.21 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 | ||||