The adversary maintains long-lived access by residing within mission ground infrastructure that already has end-to-end reach to the spacecraft. Persistence can exist in operator workstations and mission control software, schedulers/orchestrators, station control (antenna/mount, modem/baseband), automation scripts and procedure libraries, identity and ticketing systems, and cloud-hosted mission services. With this foothold, the actor can repeatedly queue commands, updates, or file transfers during routine passes; mirror legitimate operator behavior to blend in; and refresh their tooling as software is upgraded. Presence on the ground also supports durable reconnaissance (pass plans, dictionaries, key/counter states) and continuous staging so each window to the vehicle can be exploited without re-establishing access.
| ID | Name | Tiering | Description | NIST Rev5 | ISO 27001 | Onboard SV | Ground | |
| CM0033 | Relay Protection | Replay attacks capture and later retransmit previously valid authentication messages, frames, credentials, or tokens. Relay attacks forward an authentication exchange in real time between legitimate endpoints, causing an endpoint to authenticate a connection or action that the adversary is relaying without requiring compromise of the underlying cryptographic keys. Relay- and replay-resistant authentication mechanisms must be implemented when establishing remote connections or security associations with the spacecraft and for authenticated communications on spacecraft internal buses. The protections must prevent previously accepted authentication material or authenticated traffic from being reused outside its authorized context. Replay resistance should use freshness and anti-reuse mechanisms such as nonces, sequence numbers, timestamps where operationally suitable, and managed anti-replay windows. Relay resistance additionally requires authentication to be cryptographically bound to the intended endpoints, security association, session or channel context, and authenticated action. Challenge-response authentication provides replay resistance when fresh challenges are used but does not, by itself, prevent an adversary from relaying the challenge and response between legitimate endpoints. These protections must be applied at both external interface boundaries, including ground-to-spacecraft command links and crosslinks, and internal spacecraft bus connections where component-to-component authentication is implemented. | AC-17(10) IA-2(8) IA-3 IA-3(1) IA-4 IA-7 SC-13 SC-16(1) SC-23 SC-23(1) SC-23(3) SC-7 SC-7(11) SC-7(18) SI-10 SI-10(5) SI-10(6) SI-3(8) | A.5.16 A.5.14 A.8.16 A.8.20 A.8.22 A.8.23 A.8.26 A.8.24 A.8.26 A.5.31 | ||||
| CM0036 | Session Termination | Where session-oriented communications are used between ground systems and spacecraft, between ground system components, or across internal spacecraft interfaces, the associated connection or session must be terminated upon completion or after a period of inactivity exceeding a threshold defined in the mission’s concept of operations (CONOPS). Failure to terminate idle or completed sessions leaves authenticated connections open and exploitable, providing adversaries with an opportunity to inject commands or data into an existing authenticated session without needing to complete the authentication process independently. Inactivity timeout thresholds must be established through the CONOPS process rather than set arbitrarily, balancing the security benefit of rapid session termination against the operational consequences of terminating a session that an operator or automated process may legitimately require across a contact gap or processing delay. Session termination must invalidate the associated session identifiers, authorization state, and cryptographic session state so that the terminated session cannot be reused. Where secure session resumption is operationally required, it must use a mission-approved, cryptographically protected mechanism with defined validity limits and must not permit reuse of expired, revoked, or invalidated session state. | AC-12 AC-12(2) SC-10 SI-14(3) SI-4(7) | A.8.20 | ||||
| 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 | ||||
| CM0032 | On-board Intrusion Detection & Prevention | An on-board intrusion detection and prevention system (IDS/IPS) monitors mission-critical spacecraft components and systems, generates and stores audit records, and supports mission-approved responses to detected threats. Depending on the mission architecture, threat, and availability of ground support, responses may be autonomous, ground-directed, or a combination of both. The system should address both known attack patterns and previously unseen anomalous behavior through complementary signature-based and behavior- or anomaly-based detection methods. Machine learning or adaptive technologies may be used when their performance, resource consumption, and failure behavior have been validated for the mission environment. Detection and response coverage should address applicable adversary activities across the attack lifecycle, including initial access, execution, persistence, defense evasion, and exfiltration. The on-board IDS/IPS must be integrated with the spacecraft's traditional fault management system to provide a unified approach to anomaly response, ensuring that cyber-triggered responses are compatible with fault management logic and do not produce unintended effects or fratricide against the spacecraft's own systems; countermeasures that are incompatible with fault management are considered unsafe and must not be executed autonomously. The response hierarchy must prioritize vehicle safety and continued mission operations. Advanced containment or deception responses may be considered when they can be executed without unacceptable mission risk. The system should preserve evidence that supports post-event analysis, threat characterization, and potential attribution by authorized ground support. | AU-14 AU-2 AU-3 AU-3(1) AU-4 AU-4(1) AU-5 AU-5(2) AU-5(5) AU-6(1) AU-6(4) AU-8 AU-9 AU-9(2) AU-9(3) CA-7(6) CM-11(3) CP-10 CP-10(4) IR-4 IR-4(11) IR-4(12) IR-4(14) IR-4(5) IR-5 IR-5(1) PL-8 PL-8(1) RA-10 RA-3(4) SA-8(21) SA-8(22) SA-8(23) SC-16(2) SC-32(1) SC-5 SC-5(3) SC-7(10) SC-7(9) SI-10(6) SI-16 SI-17 SI-3 SI-3(10) SI-3(8) SI-4 SI-4(1) SI-4(10) SI-4(11) SI-4(13) SI-4(16) SI-4(17) SI-4(2) SI-4(23) SI-4(24) SI-4(25) SI-4(4) SI-4(5) SI-4(7) SI-6 SI-7(17) SI-7(8) | A.8.15 A.8.15 A.8.6 A.8.17 A.5.33 A.8.15 A.8.15 A.5.29 A.5.25 A.5.26 A.5.27 A.5.8 A.5.7 A.8.12 A.8.7 A.8.16 A.8.16 A.8.16 A.8.16 | ||||