Adversaries obtain first execution by riding connections that the mission already trusts, formal interconnections with partners, vendors, and user communities. Once a third party is compromised, the actor inherits that entity’s approved routes into mission enclaves: VPNs and jump hosts into ground networks, API keys into cloud tenants, automated file drops that feed command or update pipelines, and collaboration spaces where procedures and dictionaries circulate. Because traffic, credentials, and artifacts originate from known counterparts, the initial execution event can appear as a routine payload task, scheduled procedure, or software update promoted through established processes.
| 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 | ||||
| CM0025 | Supplier Review | A supplier review is a structured pre-contract assessment conducted before entering into any agreement with a contractor or subcontractor for the acquisition of systems, system components, or system services. The review evaluates the prospective supplier's security posture, trustworthiness, and capability to deliver components or services that meet the mission's integrity and assurance requirements, before contractual commitments are made and before the supplier gains access to mission information or influence over mission systems. Supplier reviews reduce the risk of introducing supply chain vulnerabilities through poorly qualified, compromised, or adversary-influenced suppliers at any tier of the acquisition chain. The rigor and depth of the review should be calibrated to the criticality of the components or services being acquired, with suppliers of mission-critical hardware, software, or services subject to the most intensive assessment. Supplier review findings should inform not only the decision to contract but also the specific security requirements, oversight provisions, and flow-down obligations included in the resulting agreement. | PL-8 PL-8(1) PL-8(2) PM-30 PM-30(1) RA-3(1) SA-11 SA-11(3) SA-17 SA-2 SA-3 SA-8 SA-9 SR-11 SR-3(1) SR-3(3) SR-4 SR-4(1) SR-4(2) SR-4(3) SR-4(4) SR-5 SR-5(1) SR-5(2) SR-6 | A.5.8 4.4 6.2 7.5.1 7.5.2 7.5.3 10.2 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 A.8.29 A.8.30 A.8.25 A.8.27 A.5.21 A.8.30 A.5.20 A.5.21 A.5.23 A.8.29 A.5.22 | ||||
| CM0041 | User Training | Human factors represent one of the most consistently exploited attack vectors against space mission systems; adversaries routinely use spear phishing, social engineering, and other user-interaction techniques to gain initial access to mission networks, development environments, and operational infrastructure. User training reduces this attack surface by building personnel awareness of adversary techniques and the behaviors required to recognize and resist them. Training must be role-differentiated: general security awareness training is required for all personnel with access to mission systems, while personnel with assigned security roles and responsibilities require additional role-based training commensurate with the specific duties and access rights they hold. Training must be completed before a user is granted access to mission systems or authorized to perform assigned security duties; updated when system changes introduce new threats, procedures, or access controls that alter the security context in which personnel operate; and refreshed at least annually, or more frequently if the mission's security policy specifies a shorter interval. Training program effectiveness should be measurable, with completion records maintained and knowledge validation incorporated to confirm that training objectives are being achieved rather than simply delivered. | AT-2 AT-2(1) AT-2(4) AT-2(5) AT-2(6) AT-3 AT-3(3) CP-2 CP-4(1) CP-4(2) IR-2(3) IR-3(2) IR-8 SA-9 SR-11(1) | 7.3 A.6.3 A.8.7 A.6.3 7.5.1 7.5.2 7.5.3 A.5.2 A.5.29 A.8.1 A.5.30 7.5.1 7.5.2 7.5.3 A.5.24 A.5.2 A.5.4 A.5.8 A.5.14 A.5.22 A.5.23 A.8.21 | ||||
| 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 | ||||
| CM0034 | Monitor Critical Telemetry Points | Monitoring defined spacecraft telemetry points provides a key source of evidence for detecting adversary activity against on-orbit systems, where observability is largely limited to the events and conditions the spacecraft can sense, record, and report. Monitored telemetry must include both accepted and rejected commands, command mode transitions, command counters, and other indicators of commanding activity, enabling detection of unauthorized command attempts that fail authentication as well as anomalous patterns in legitimate command traffic. Monitoring scope should include RF and link-quality indicators that support detection and triage of interference or suspected jamming. These indicators should be correlated with expected link conditions and other available evidence before hostile activity is concluded. Security-relevant telemetry should be integrated and time-correlated with ground-based defensive cyber operations infrastructure, including security information and event management (SIEM) and audit platforms, to provide unified space-system cybersecurity situational awareness. The resulting view should correlate spacecraft observations with relevant ground-system security events while accounting for telemetry latency, contact availability, and other observability limitations. | AC-17(1) AU-3(1) CA-7(6) IR-4(14) PL-8 PL-8(1) SA-8(13) SC-16 SC-16(1) SC-7 SI-3(8) SI-4(7) | A.8.16 A.5.8 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 | ||||
| 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 | ||||