Robust Fault Management

Ensure fault management system cannot be used against the spacecraft. Examples include: safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of telemetry to cause action from ground, or some sort of proximity operation to cause spacecraft to go into safe mode. Understanding the safing procedures and ensuring they do not put the spacecraft in a more vulnerable state is key to building a resilient spacecraft.

NIST Rev5 Controls

D3FEND Techniques

D3FEND Artifacts

ISO 27001

NASA Best Practice Guide

ESA Space Shield Mitigation

None

Related MITRE EMB3D Mitigations

Related CSF 2.0

Related BSI Security Measures

No related BSI Security Measures

ID: CM0042

Tier: I

Onboard SV CM

Created: 2022/10/19

Last Modified: 2025/04/15

Techniques Addressed by Countermeasure

ID		Name	Description
IA-0010		Unauthorized Access During Safe-Mode	Adversaries time their first execution to coincide with safe-mode, when the vehicle prioritizes survival and recovery. In many designs, safe-mode reconfigures attitude, reduces payload activity, lowers data rates, and enables contingency dictionaries or maintenance procedures that are dormant in nominal operations. Authentication, rate/size limits, command interlocks, and anti-replay handling may differ; some implementations reset counters, relax timetag screening, accept broader command sets, or activate alternate receivers and beacons to improve commandability. Ground behavior also shifts: extended passes, emergency scheduling, and atypical station use create predictable windows. An attacker who understands these patterns can present syntactically valid traffic that aligns with safe-mode expectations, maintenance loads, recovery scripts, table edits, or reboot/patch sequences, so the first accepted action appears consistent with fault recovery rather than intrusion.
EX-0006		Disable/Bypass Encryption	The adversary alters how confidentiality or integrity is applied so traffic or data is processed in clear or with weakened protection. Paths include toggling configuration flags that place links or storage into maintenance/test modes; forcing algorithm “fallbacks” or null ciphers; downgrading negotiated suites or keys; manipulating anti-replay/counter state so checks are skipped; substituting crypto libraries or tables during boot/update; and selecting alternate routes that carry the same content without encryption. On some designs, distinct modes handle authentication and confidentiality separately, allowing an actor who obtains authentication material to request unencrypted service or to switch to legacy profiles. The end state is that command, telemetry, or data products traverse a path the spacecraft accepts while cryptographic protection is absent, weakened, or inconsistently applied, enabling subsequent tactics such as inspection, manipulation, or exfiltration.
EX-0008		Time Synchronized Execution	Malicious logic is arranged to run at precise times derived from onboard clocks or distributed time sources. The trigger may be absolute or relative. Spacecraft commonly maintain multiple clocks and counters and schedule autonomous sequences against them. An attacker leverages this machinery to ensure effects occur during tactically advantageous windows. Time-based execution reduces exposure, simplifies coordination across assets, and makes reproduction difficult in lab settings that lack the same temporal context.
	.01	Absolute Time Sequences	Execution is keyed to a fixed wall-clock timestamp or epoch, independent of current vehicle state. The implant watches a trusted time source, GNSS-derived time, crosslink-distributed network time, oscillator-disciplined UTC/TAI, or mission elapsed time anchored at activation, and triggers exactly at a programmed date/time. Absolute triggering supports coordinated multi-asset actions and allows long dormancy with a precise activation moment. Variants incorporate calendar logic (e.g., “first visible pass after YYYY-MM-DD hh:mm:ss”) or guard bands to fire only if the clock is within certain tolerances, ensuring the event occurs even with minor drift yet remains rare enough to blend with scheduled operations.
	.02	Relative Time Sequences	Execution is keyed to elapsed time since a reference event. The implant latches a start point, boot, reset, safing entry/exit, receipt of a particular telemetry/command pattern, achievement of sun-pointing, and arms a countdown or set of offsets (“N seconds after event,” “repeat every M cycles”). Relative sequences are resilient to clock discontinuities and mirror how many spacecraft schedule internal activities (e.g., after boot, run calibrations; after acquisition, start downlink). An attacker exploits this to ensure the trigger fires only within specific operational phases and to survive resets that would thwart absolute timestamps: after every reboot, wait for housekeeping steady state, then act; or, after a wheel unload completes, inject an additional command while control laws are in a known configuration.
EX-0009		Exploit Code Flaws	The adversary executes actions on-board by abusing defects in software that runs on the vehicle, ranging from application logic in flight software to libraries, drivers, and supporting services. Outcomes range from arbitrary code execution and privilege escalation to silent logic manipulation (e.g., bypassing interlocks, suppressing alarms) that appears operationally plausible. The hallmark of this technique is that the attacker co-opts existing code paths, often rarely used ones, to run unintended behavior under nominal interfaces. These attacks may be extremely targeted and tailored to specific coding errors introduced as a result of poor coding practices or they may target known issues in the commercial software components.
	.01	Flight Software	Flight software presents rich attack surface where mission-specific parsing and autonomy live. Vulnerable components include command and telemetry handlers, table loaders, file transfer services, mode management and safing logic, payload control applications, and gateway processes that bridge payload and bus protocols. Typical flaws are unchecked lengths and indices in command fields, arithmetic overflows in rate/size calculations, insufficient validation of table contents, format-string misuse in logging, incomplete state cleanup across rapid mode changes, and race conditions in concurrent message processing. Some FSW suites expose operator-facing APIs or scripting/procedure engines used for automation; malformed invocations can coerce unexpected behaviors or enable arbitrary expressions. Because many subsystems act on “last write wins,” logic errors can yield durable configuration changes without obvious anomalies in protocol syntax. Successful exploitation lets an adversary execute code, alter persistent parameters, or chain effects across partitions that would otherwise be segmented by design.
	.02	Operating System	At the OS layer the attacker targets primitives that schedule work and mediate hardware. Maintenance builds may expose shells or management consoles; misconfigurations around these interfaces can provide paths to command interpreters or privileged syscalls. Exploitation yields kernel-mode execution, arbitrary memory read/write, or control of scheduling and address spaces, letting the actor tamper with FSW processes, intercept command paths, or manipulate storage and bus drivers beneath application checks. The technique leverages generic OS weaknesses adapted to the spacecraft’s particular build, turning low-level control into mission-facing effects that appear to originate from legitimate processes.
EX-0010		Malicious Code	The adversary achieves on-board effects by introducing executable logic that runs on the vehicle, either native binaries and scripts, injected shellcode, or “data payloads” that an interpreter treats as code (e.g., procedure languages, table-driven automations). Delivery commonly piggybacks on legitimate pathways: software/firmware updates, file transfer services, table loaders, maintenance consoles, or command sequences that write to executable regions. Once staged, activation can be explicit (a specific command, mode change, or file open), environmental (time/geometry triggers), or accidental, where operator actions or routine autonomy invoke the implanted logic. Malicious code can target any layer it can reach: altering flight software behavior, manipulating payload controllers, patching boot or device firmware, or installing hooks in drivers and gateways that bridge bus and payload traffic. Effects range from subtle logic changes (quiet data tampering, command filtering) to overt actions (forced mode transitions, resource starvation), and may include secondary capabilities like covert communications, key material harvesting, or persistence across resets by rewriting images or configuration entries.
	.01	Ransomware	Ransomware on a spacecraft encrypts data or critical configuration so that nominal operations can no longer proceed without the attacker’s cooperation. Targets include mass-memory file stores (engineering telemetry, payload data), configuration and command tables, event logs, on-board ephemerides, and even intermediate buffers used by downlink pipelines. Some variants interfere with key services instead of bulk data, e.g., encrypting a command dictionary or table index so valid inputs are rejected, or wrapping the payload data path in an attacker-chosen cipher so downlinked products appear as noise. By denying access to on-board content or control artifacts at scale, attackers convert execution into bargaining power or irreversible mission degradation.
	.02	Wiper Malware	Wipers deliberately destroy or irreversibly corrupt data and, in some cases, executable images to impair or end mission operations. Destructive routines may overwrite with patterns or pseudorandom data, repeatedly reformat volumes, trigger wear mechanisms on non-volatile memory, or manipulate low-level translation layers so recovery tools see a blank or inconsistent device. Activation can be immediate or staged, sleeping until a specific time, pass, or maintenance action, and may be paired with anti-recovery steps such as erasing checksums, undo logs, or golden images. Because wipers operate at storage and image layers that underpin many subsystems, collateral effects can cascade: autonomy enters safing without viable recovery paths, downlinks carry only noise, and subsequent updates cannot be authenticated or applied. The defining feature is irreversible loss of data or executables as the primary objective, rather than concealment or monetization.
	.03	Rootkit	A rootkit hides the presence and activity of other malicious components by interposing on the mechanisms that report system state. On spacecraft this can occur within flight software processes, at OS kernel level, inside separation kernels/hypervisors, or down in system firmware where drivers and initialization routines run. Techniques include API and syscall hooking, patching message queues and inter-process communication paths, altering task lists and scheduler views, filtering telemetry packets and event logs, and rewriting sensor or health values before they are recorded or downlinked. Rootkits may also hook command handlers and gateways so certain opcodes, timetags, or sources are silently accepted or ignored while external observers see normal acknowledgments. Because many missions rely on deterministic procedures and limited observability, even small alterations to reporting can make malicious actions appear as plausible mode transitions or benign anomalies. Persistence often pairs with the concealment layer, with the rootkit reinjecting companions after resets or rebuilds by monitoring for specific files, tables, or image loads and modifying them on the fly.
	.04	Bootkit	A bootkit positions itself in the pre-OS boot chain so that it executes before normal integrity checks and can shape what the system subsequently trusts. After seizing early control, the bootkit can redirect image selection, patch kernels or flight binaries in memory, adjust device trees and driver tables, or install hooks that persist across warm resets. Some variants maintain shadow copies of legitimate images and present them to basic verification routines while steering actual execution to a modified payload; others manipulate fallback logic so recovery modes load attacker-controlled code. Because the boot path initializes memory maps, buses, and authentication material, a bootkit can also influence key/counter setup and gateway configurations, creating conditions favorable to later tactics. The central characteristic is precedence: by running first, the implant defines the reality higher layers observe, ensuring that every subsequent component launches under conditions curated by the attacker.
EX-0011		Exploit Reduced Protections During Safe-Mode	The adversary times on-board actions to the period when the vehicle is in safe-mode and operating with altered guardrails. In many designs, safe-mode enables contingency command dictionaries, activates alternate receivers or antennas, reduces data rates, and prioritizes survival behaviors (sun-pointing, thermal/power conservation). Authentication checks, anti-replay windows, rate/size limits, and interlocks may differ from nominal; counters can be reset, timetag screening relaxed, or maintenance procedures made available for recovery. Ground cadence also changes, longer passes, emergency scheduling, atypical station selection, creating predictable windows for interaction. Using knowledge of these patterns, an attacker issues maintenance-looking loads, recovery scripts, parameter edits, or boot/patch sequences that the spacecraft is primed to accept while safed. Because responses (telemetry beacons, acknowledgments, mode bits) resemble normal anomaly recovery, the first execution event blends with expected behavior, allowing unauthorized reconfiguration, software modification, or state manipulation to occur under the cover of fault response.
EX-0012		Modify On-Board Values	The attacker alters live or persistent data that the spacecraft uses to make decisions and route work. Targets include device and control registers, parameter and limit tables, internal routing/subscriber maps, schedules and timelines, priority/QoS settings, watchdog and timer values, autonomy/FDIR rule tables, ephemeris and attitude references, and power/thermal setpoints. Many missions expose legitimate mechanisms for updating these artifacts, direct memory read/write commands, table load services, file transfers, or maintenance procedures, which can be invoked to steer behavior without changing code. Edits may be transient (until reset) or latched/persistent across boots; they can be narrowly scoped (a single bit flip on an enable mask) or systemic (rewriting a routing table so commands are misdelivered). The effect space spans subtle biasing of control loops, selective blackholing of commands or telemetry, rescheduling of operations, and wholesale changes to mode logic, all accomplished by modifying the values the software already trusts and consumes.
	.01	Registers	Threat actors may target the internal registers of the victim spacecraft in order to modify specific values as the FSW is functioning or prevent certain subsystems from working. Most aspects of the spacecraft rely on internal registers to store important data and temporary values. By modifying these registers at certain points in time, threat actors can disrupt the workflow of the subsystems or onboard payload, causing them to malfunction or behave in an undesired manner.
	.02	Internal Routing Tables	Threat actors may rewrite the maps that tell software where to send and receive things. In publish/subscribe or message-queued flight frameworks, tables map message IDs to subscribers, opcodes to handlers, and pipes to processes; at interfaces, address/port maps define how traffic traverses bridges and gateways (e.g., SpaceWire node/port routes, 1553 RT/subaddress mappings, CAN IDs). By altering these structures, commands can be misdelivered, dropped, duplicated, or routed through unintended paths; telemetry can be redirected or blackholed; and handler bindings can be swapped so an opcode triggers the wrong function. Schedule/routing hybrids, used to sequence activities and distribute results, can be edited to reorder execution or to create feedback loops that occupy bandwidth and processor time. The result is control over who hears what and when, achieved by changing the lookup tables that underpin command/telemetry distribution rather than the code that processes them.
	.03	Memory Write/Loads	The adversary uses legitimate direct-memory commands or load services to place chosen bytes at chosen addresses. Many spacecraft support raw read/write operations, block loads into RAM or non-volatile stores, and table/file loaders that copy content into working memory. With knowledge of address maps and data structures, an attacker can patch function pointers or vtables, alter limit and configuration records, seed scripts or procedures into interpreter buffers, adjust DMA descriptors, or overwrite portions of executable images resident in RAM. Loads may be sized and paced to fit link and queue constraints, then activated by a subsequent command, mode change, or natural reference by the software.
	.04	App/Subscriber Tables	In publish/subscribe flight frameworks, applications and subsystems register interest in specific message classes via subscriber (or application) tables. These tables map message IDs/topics to subscribers, define delivery pipes/queues, and often include filters, priorities, and rate limits. By altering these mappings, an adversary can quietly reshape information flow: critical consumers stop receiving health or sensor messages; non-critical tasks get flooded; handlers are rebound so an opcode or message ID reaches the wrong task; or duplicates create feedback loops that consume bandwidth and CPU. Because subscription state is usually read at init or refreshed on command, subtle edits can persist across reboots or take effect at predictable times. Similar effects appear in legacy MIL-STD-1553 deployments by modifying Remote Terminal (RT), subaddress, or mode-code configurations so that messages are misaddressed or dropped at the bus interface. The net result is control-by-misdirection: the software still “works,” but the right data no longer reaches the right recipient at the right time.
	.05	Scheduling Algorithm	Spacecraft typically rely on real-time scheduling, fixed-priority or deadline/periodic schemes, driven by timers, tick sources, and per-task parameters. Threat actors target these parameters and associated tables to skew execution order and timing. Edits may change priorities, periods, or deadlines; adjust CPU budgets and watchdog thresholds; alter ready-queue disciplines; or reconfigure timer tick rates and clock sources. They may also modify task affinities, message-queue depths, and interrupt masks so preemption and latency characteristics shift. Small changes can have large effects: high-rate control loops see added jitter, estimator updates miss deadlines, command/telemetry handling starves, or low-priority maintenance tasks monopolize cores due to mis-set periods. Manipulated schedules can create intermittent, state-dependent malfunctions that are hard to distinguish from environmental load. The essence of the technique is to weaponize time, reshaping when work happens so that otherwise correct code produces unsafe or exploitable behavior.
	.06	Science/Payload Data	Payload data, and the metadata that gives it meaning, can be altered in place to steal value, mislead users, or degrade mission outputs. Targets include raw detector frames, packetized Level-0 streams, onboard preprocessed products, and file catalogs/directories on mass memory. Adjacent metadata such as timestamps, pointing/attitude tags, calibration coefficients, compression settings, and quality flags are equally potent; slight bias in a calibration table or time tag can skew entire downlink campaigns while appearing routine. An adversary may rewrite frame headers, reorder packets, substitute segments from prior passes, or flip quality bits so ground pipelines silently discard or misclassify products. Recorder index manipulation can orphan files or cause downlinks to serve stale or fabricated content. Because many missions perform some processing or filtering onboard, tampering upstream of downlink propagates forward as “authoritative” truth, jeopardizing mission objectives without obvious protocol anomalies.
	.07	Propulsion Subsystem	Propulsion relies on parameters and sensed values that govern burns, pressure management, and safing. Editable items include thruster calibration and minimum impulse bit, valve timing and duty limits, inhibit masks, delta-V tables, plume keep-out constraints, tank pressure/temperature thresholds, leak-detection limits, and momentum-management coupling with attitude control. By modifying these, an adversary can provoke over-correction, waste propellant through repeated trims, bias orbit maintenance, or trigger protective sequences at inopportune times. False pressure or temperature readings can cause autonomous venting or lockouts; tweaked alignment matrices or misapplied gimbal limits can yield off-axis thrust and attitude excursions; altered desaturation rules can induce frequent wheel unloads that sap resources. Because consumables are finite and margins tight, even modest parameter drift can shorten mission life or violate keep-out and conjunction constraints while presenting as “normal” control activity.
	.08	Attitude Determination & Control Subsystem	ADCS depends on tightly coupled models and parameters: star-tracker catalogs and masks, sensor alignments and bias terms, gyro scale factors and drift rates, estimator covariances and process/measurement noise, controller gains and saturation limits, wheel/CMG torque constants, magnetic torquer maps, and sun sensor thresholds. Editing these values skews estimation or control, producing slow bias, limit cycles, loss of lock, or abrupt safing triggers. For example, a small change to a star-tracker mask can force frequent dropouts; an inflated gyro bias drives the filter away from truth; softened actuator limits or mis-set gains let disturbances accumulate; altered sun-point entry criteria cause unnecessary mode switches. Secondary impacts propagate to power, thermal, and communications because pointing and geometry underpin array generation, radiator view factors, and antenna gain. The technique turns the spacecraft against itself by nudging the parameters that close the loop between what the vehicle believes and how it responds.
	.09	Electrical Power Subsystem	Adversaries alter parameters and sensed values that govern power generation, storage, and distribution so the spacecraft draws or allocates energy in harmful ways. Editable items include bus voltage/current limits, MPPT setpoints and sweep behavior, array and SADA modes, battery charge/discharge thresholds and temperature derates, state-of-charge estimation constants, latching current limiter (LCL) trip/retry settings, load-shed priorities, heater duty limits, and survival/keep-alive rules. By changing these, a threat actor can drive excess consumption (e.g., disabling load shed, raising heater floors), misreport remaining energy (skewed SoC), or push batteries outside healthy ranges, producing brownouts, repeated safing, or premature capacity loss. Manipulating thresholds and hysteresis can also create oscillations where loads repeatedly drop and re-engage, wasting energy and stressing components. The effect is accelerated depletion or misallocation of finite power, degrading mission operations and potentially preventing recovery after eclipse or anomalies.
	.10	Command & Data Handling Subsystem	C&DH relies on tables and runtime values that define how commands are parsed, queued, and dispatched and how telemetry is collected, stored, and forwarded. Targets include opcode-to-handler maps, argument limits and schemas, queue depths and priorities, message ID routing, publish/subscribe bindings, timeline/schedule entries, file catalog indices, compression and packetization settings, and event/telemetry filters. Edits to these artifacts reshape control and visibility: commands are delayed, dropped, or misrouted; telemetry is suppressed or redirected; timelines slip; and housekeeping/data products are repackaged in ways that confuse ground processing. Because many frameworks treat these values as authoritative configuration, small changes can silently propagate across subsystems, degrading responsiveness, creating backlogs, or severing the logical pathways that keep the vehicle coordinated, without modifying the underlying code.
	.11	Watchdog Timer (WDT)	Watchdogs supervise liveness by requiring software to “pet” within defined windows or the system resets. Threat actors manipulate WDT behavior by changing timeout durations, windowed-WDT bounds, reset actions, enable/mask bits, or the source that performs the petting (e.g., moving it into a low-level ISR so higher layers can be stalled indefinitely). Software WDTs can be disabled or starved; hardware WDTs are influenced via control registers, strap pins, or supervisor commands that alter prescalers and reset ladders. Outcomes include preventing intended resets so runaway tasks consume power and bandwidth, or forcing repeated resets at tactically chosen moments, e.g., during updates or handovers, to keep the system in a degraded or easily predictable state. The technique converts a safety mechanism into a tool for either unbounded execution or rhythmic disruption, depending on how the WDT parameters are rewritten.
	.12	System Clock	Spacecraft maintain multiple time bases and distribute time to schedule sequences, validate timetags, manage anti-replay counters, and align navigation/attitude processing. By writing to clock registers, altering time-distribution services, switching disciplining sources, or biasing oscillator parameters, an adversary can skew these references. Effects include reordering or prematurely firing stored command sequences, invalidating timetag checks, desynchronizing counters used by authentication or ranging, misaligning estimator windows, and corrupting timestamped payload data. Even small offsets can accumulate into observable misbehavior when autonomy and scheduling depend on tight temporal guarantees. The result is execution that happens at the wrong moment, or not at all, because the system’s notion of “now” has been shifted.
	.13	Poison AI/ML Training Data	When missions employ AI/ML, for onboard detection/classification, compression, anomaly screening, guidance aids, or ground-side planning, training data becomes a control surface. Data poisoning inserts crafted examples or labels into the training corpus or fine-tuning set so the resulting model behaves incorrectly while appearing valid. Variants include clean-label backdoors (benign-looking samples with a hidden trigger that later induces a targeted response), label flipping and biased sampling (to skew decision boundaries), and corruption of calibration/ground-truth products that the pipeline trusts. For space systems, poisoning may occur in science archives, test vectors, simulated scenes, or housekeeping datasets used to train autonomy/anomaly models; models trained on poisoned corpora are then packaged and uplinked as routine updates. Once fielded, a simple trigger pattern in imagery, telemetry, or RF features can cause misclassification, suppression, or false positives at the time and place the adversary chooses, turning model behavior into an execution mechanism keyed by data rather than code.
EX-0013		Flooding	Flooding overwhelms a communication or processing path by injecting traffic at rates or patterns the system cannot comfortably absorb. In space contexts this can occur across layers: RF/optical links (continuous carriers, wideband noise, or protocol-shaped bursts); link/protocol layers (valid-looking frames at excessive cadence); application layers (command and telemetry messages that saturate parsers and queues); and internal vehicles buses where repeated messages starve critical publishers. Effects range from outright denial of service, dropped commands, lost telemetry, missed windows, to subtler corruption, such as out-of-order processing, watchdog trips, or autonomy entering protective modes due to backlogged health data. Secondary impacts include power and thermal strain as decoders, modems, or software loops spin at maximum duty, storage filling from retries, and control loops jittering when their messages are delayed. Timing matters: floods during handovers, maneuvers, or safing transitions can magnify consequences because margins are thinnest.
	.01	Valid Commands	Here the adversary saturates paths with legitimate telecommands or bus messages so the spacecraft burns scarce resources honoring them. Inputs may be innocuous (no-ops, time queries, telemetry requests) or low-risk configuration edits, but at scale they consume command handler cycles, fill queues, generate events and logs, trigger acknowledgments, and provoke downstream work in subsystems (e.g., repeated state reports, mode toggles, or file listings). On internal buses, valid actuator or housekeeping messages replayed at high rate can starve higher-priority publishers or cause control laws to chase stale stimuli. Because the traffic is syntactically correct, and often contextually plausible, the system attempts to process it rather than discard it early, increasing CPU usage, memory pressure, and power draw. Consequences include delayed or preempted legitimate operations, transient loss of commandability, and knock-on FDIR activity as deadlines slip and telemetry appears inconsistent.
	.02	Erroneous Input	In this variant, the attacker injects non-useful energy or data, noise, malformed frames, or near-valid messages, so receivers and parsers labor to acquire, decode, and reject it. At the RF layer, wideband or protocol-shaped interference drives AGC and clock recovery to hunt, elevates BER, and forces repeated acquisitions; at the link layer, frames with correct preambles but bad CRCs keep decoders busy while yielding no payload; at the application layer, malformed packets force parse/validate/deny cycles that still consume CPU and fill error logs. On internal buses, collisions or bursts of misaddressed traffic reduce effective bandwidth and reorder legitimate messages. Even though little of the injected content passes semantic checks, the effort of dealing with it crowds out real work and may trigger retransmission storms or fallback modes that further increase load. The hallmark is volumetric invalid activity, crafted to engage front ends and parsers just long enough, that degrades integrity and availability without relying on privileged or authenticated commands.
EX-0014		Spoofing	The adversary forges inputs that subsystems treat as trustworthy truth, time tags, sensor measurements, bus messages, or navigation signals, so onboard logic acts on fabricated reality. Because many control loops and autonomy rules assume data authenticity once it passes basic sanity checks, carefully shaped spoofs can trigger mode transitions, safing, actuator commands, or payload behaviors without touching flight code. Spoofing may occur over RF (e.g., GNSS, crosslinks, TT&C beacons), over internal networks/buses (message injection with valid identifiers), or at sensor/actuator interfaces (electrical/optical stimulation that produces plausible readings). Effects range from subtle bias (drifting estimates, skewed calibrations) to acute events (unexpected slews, power reconfiguration, recorder re-indexing), and can also pollute downlinked telemetry or science products so ground controllers interpret a false narrative. The hallmark is that the spacecraft chooses the adversary’s action path because the forged data passes through normal processing chains.
	.01	Time Spoof	Time underpins sequencing, anti-replay, navigation filtering, and data labeling. An attacker that forges or biases the time seen by onboard consumers can reorder stored command execution, break timetag validation, desynchronize counters, and misalign estimation windows. Spoofing vectors include manipulating the distributed time service, introducing a higher-priority/cleaner time source (e.g., GNSS-derived time), or crafting messages that cause clock discipline to slew toward attacker-chosen values. Once time shifts, autonomous routines keyed to epochs, wheel unloads, downlink starts, heater schedules, fire early/late or not at all, and telemetry appears inconsistent to ground analysis. The signature is correct-looking time metadata that steadily or abruptly departs from truth, driving downstream logic to act at the wrong moment.
	.02	Bus Traffic Spoofing	Here the adversary forges messages on internal command/data paths (e.g., 1553, SpaceWire, CAN, custom). By emitting frames with valid identifiers, addresses, and timing, the attacker can make subscribers accept actuator setpoints, power switch toggles, mode changes, or housekeeping values that originated off-path. Because many consumers act on “latest value wins” or on message cadence, forged traffic can mask real publishers, starve critical topics, or force handlers to execute unintended branches. Gateways that translate between networks amplify impact: a spoofed message on one side can propagate to multiple domains as legitimate payload. Outcomes include misdelivered commands, silent configuration drift, and control loops chasing phantom stimuli, all while bus monitors show protocol-conformant traffic.
	.03	Sensor Data	The attacker presents fabricated or biased measurements that estimation and control treat as ground truth. Targets include attitude/position sensors (star trackers, gyros/IMUs, sun sensors, magnetometers, GNSS), environmental and health sensors (temperatures, currents, voltages, pressures), and payload measurements used in autonomy. Spoofs may be injected electrically at interfaces, optically (blinding/dazzling trackers or sun sensors), magnetically, or by crafting packets fed into sensor gateways. Even small, consistent biases can drive filters to incorrect states; stepwise changes can trigger fault responses or mode switches. Downstream, timestamps, quality flags, and derived products inherit the deception, creating uncertainty for operators and potentially inducing temporary loss of service as autonomy reacts to a world that never existed.
	.04	Position, Navigation, and Timing (PNT) Spoofing	The adversary transmits GNSS-like signals (or manipulates crosslink-distributed time/ephemeris) so the spacecraft’s navigation solution reflects attacker-chosen states. With believable code phases, Doppler, and navigation messages, the victim can be pulled to a false position/velocity/time, causing downstream functions, attitude pointing limits, station visibility prediction, eclipse timing, antenna pointing, and anti-replay windows, to misbehave. Even when GNSS is not the primary navigation source, spoofed PNT can bias timekeeping or seed filters that fuse multiple sensors, leading to mis-scheduling and errant control. The defining feature is externally provided navigation/time that passes validity checks yet encodes a crafted trajectory or epoch.
PER-0004		Replace Cryptographic Keys	The adversary cements control by changing the cryptographic material the spacecraft uses to authenticate or protect links and updates. Targets include uplink authentication keys and counters, link-encryption/session keys and key-encryption keys (KEKs), key identifiers/selectors, and algorithm profiles. Using authorized rekey commands or key-loading procedures, often designed for over-the-air use, the attacker installs new values in non-volatile storage and updates selectors so subsequent traffic must use the attacker’s keys to be accepted. Variants desynchronize anti-replay by advancing counters or switching epochs, or strand operators by flipping profiles to a mode for which only the adversary holds parameters. Once replaced, the new material persists across resets and mode changes, turning the spacecraft into a node that recognizes the adversary’s channel while rejecting former controllers.
DE-0001		Disable Fault Management	The adversary suppresses or alters fault detection, isolation, and recovery (FDIR) so unauthorized actions proceed without triggering safing or alerts. Targets include watchdogs and heartbeat monitors; limit and sanity checks on sensor/command values; command interlocks and inhibit masks; voting and redundancy-management logic; and event/alert generation and routing. Techniques range from patching or bypassing checks in flight code, to rewriting parameter/limit tables, to muting publishers that report faults. More subtle variants desensitize thresholds, freeze counters, or delay responses just long enough for a malicious sequence to complete. With FDIR dulled or offline, anomalous states resemble nominal behavior and automated mitigations do not engage, masking the attack from ground oversight.
DE-0002		Disrupt or Deceive Downlink	Threat actors may target ground-side telemetry reception, processing, or display to disrupt the operator’s visibility into spacecraft health and activity. This may involve denial-based attacks that prevent the spacecraft from transmitting telemetry to the ground (e.g., disabling telemetry links or crashing telemetry software), or more subtle deception-based attacks that manipulate telemetry content to conceal unauthorized actions. Since telemetry is the primary method ground controllers rely on to monitor spacecraft status, any disruption or manipulation can delay or prevent detection of malicious activity, suppress automated or manual mitigations, or degrade trust in telemetry-based decision support systems.
	.03	Inhibit Spacecraft Functionality	In this variant, telemetry is suppressed at the source by manipulating on-board generation or transmission. Methods include disabling or pausing telemetry publishers, altering packet filters and rates, muting event/report channels, reconfiguring recorder playback, retuning/muting transmitters, or switching to modes that emit only minimal beacons. The spacecraft continues operating, but the downlink no longer reflects true activity or arrives too sparsely to support monitoring. By constraining what is produced or transmitted, the adversary reduces opportunities for detection while other actions proceed.
DE-0003		On-Board Values Obfuscation	The adversary manipulates housekeeping and control values that operators and autonomy rely on to judge activity, health, and command hygiene. Targets include command/telemetry counters, event/severity flags, downlink/reporting modes, cryptographic-mode indicators, and the system clock. By rewriting, freezing, or biasing these fields, and by selecting reduced or summary telemetry modes, unauthorized actions can proceed while the downlinked picture appears routine or incomplete. The result is delayed recognition, misattribution to environmental effects, or logs that cannot be reconciled post-facto.
	.01	Vehicle Command Counter (VCC)	The VCC tracks how many commands the spacecraft has accepted. An adversary masks activity by zeroing, freezing, or selectively decrementing the VCC, or by steering actions through paths that do not increment it (maintenance dictionaries, alternate receivers, hidden handlers). They may also overwrite the telemetry field that reports the VCC so ground displays show a lower or steady count while high volumes of commands are processed. This breaks simple “command volume” heuristics and makes bursty activity look normal.
	.02	Rejected Command Counter	This counter records commands that failed checks or were refused. To hide probing and trial-and-error, the adversary suppresses increments, periodically clears the value, or forges the downlinked field so rejection rates appear benign. Variants also tamper with associated reason codes or event entries, replacing them with innocuous outcomes. Analysts reviewing telemetry see no evidence of failed attempts even as the system is being exercised aggressively.
	.03	Command Receiver On/Off Mode	By toggling receiver enable states (per-receiver, per-antenna, or per-band), the adversary creates deliberate “quiet windows” in which outside intervention cannot arrive. Turning a command receiver off, or shifting to a configuration that ignores the primary path, allows queued actions or onboard procedures to run without interruption, while operators perceive a transient loss of commandability consistent with geometry or environment. Brief, well-timed toggles can also desynchronize counters and handovers, complicating reconstruction of what occurred.
	.04	Command Receivers Received Signal Strength	Threat actors may target the on-board command receivers received signal parameters (i.e., automatic gain control (AGC)) in order to stop specific commands or signals from being processed by the spacecraft. For ground controllers to communicate with spacecraft in orbit, the on-board receivers need to be configured to receive signals with a specific signal to noise ratio (ratio of signal power to the noise power). Targeting values related to the antenna signaling that are modifiable can prevent the spacecraft from receiving ground commands.
	.05	Command Receiver Lock Modes	Receivers advertise acquisition states, bit lock, frame lock, and command lock, that indicate readiness to accept telecommands. Adversaries leverage these indicators in two ways: (1) use command-lock tests to validate geometry, power, Doppler, and polarization without risking visible command execution; and (2) tamper with the values that report lock status so ground views never show that lock was achieved. Techniques include freezing or clearing lock flags and counters, raising/lowering internal thresholds so lock occurs without being reported (or vice versa), and timing brief lock intervals between telemetry samples. The result is a window where the spacecraft is receptive to commands while downlinked status suggests otherwise.
	.06	Telemetry Downlink Modes	Spacecraft expose modes that control what telemetry is sent and how, real-time channels, recorder playback, beacon/summary only, event-driven reporting, and per-virtual-channel/APID selections. By switching modes or editing the associated parameters (rates, filters, playback queues, index ranges), an adversary can thin, defer, or reroute observability. Typical effects include suppressing high-rate engineering streams in favor of minimal beacons, delaying playback of time periods of interest, replaying benign segments, or redirecting packets to alternate virtual channels that are not routinely monitored. Telemetry continues to flow, but it no longer reflects the activity the operators need to see.
	.07	Cryptographic Modes	Many missions separate authentication from confidentiality and allow on-orbit selection of algorithms, keys, profiles, or “crypto off/clear” states. Adversaries manipulate these mode controls and selectors to desynchronize ground and space or to hide content: flipping to a profile that the ground is not using, requesting clear telemetry while maintaining authenticated uplink, or rotating key IDs so frames validate internally but appear undecodable to external tools. Mode indicators and status words can also be biased so ground displays show expected settings while the link actually operates under attacker-chosen parameters, masking command and data exchanges within normal-looking traffic.
	.08	Received Commands	Spacecraft typically maintain histories of accepted, rejected, and executed commands, buffers, logs, or file records that can be downlinked on demand or periodically. An adversary conceals activity by editing or pruning these artifacts: removing entries, altering opcodes or arguments, rewriting timestamps and source identifiers, rolling logs early, or repopulating with benign-looking commands to balance counters. Related acknowledgments and event records may be suppressed or reclassified so cross-checks appear consistent. After manipulation, the official command history shows a plausible narrative that omits or mischaracterizes the adversary’s actions.
	.09	System Clock for Evasion	The adversary biases the spacecraft’s authoritative time so that telemetry, event logs, and command histories appear shifted or inconsistent. By writing clock registers, altering disciplining sources (e.g., GNSS vs. free-running oscillator), or tweaking distribution services and offsets, they can make stored commands execute “earlier” or “later” on the timeline and misalign acknowledgments with actual actions. Downlinked frames still carry plausible timestamps near packet headers, but those stamps no longer reflect when data was produced, complicating reconstruction of sequences and masking causality during incident analysis.
	.10	GPS Ephemeris	A satellite with a GPS receiver can use ephemeris data from GPS satellites to estimate its own position in space. A hostile actor could spoof the GPS signals to cause erroneous calculations of the satellite’s position. The received ephemeris data is often telemetered and can be monitored for indications of GPS spoofing. Reception of ephemeris data that changes suddenly without a reasonable explanation (such as a known GPS satellite handoff), could provide an indication of GPS spoofing and warrant further analysis. Threat actors could also change the course of the vehicle and falsify the telemetered data to temporarily convince ground operators the vehicle is still on a proper course.
	.11	Watchdog Timer (WDT) for Evasion	By modifying watchdog parameters or who “pets” them, an adversary shapes what evidence survives. Extending or disabling timeouts allows long-running processes to operate without forced resets that would expose abnormal CPU or power usage; conversely, shortening windows or relocating the petting source to a low-level ISR can induce frequent resets that wipe volatile traces, break correlation in logs, and explain anomalies as “spurious reboots.” In both directions, the watchdog becomes a timing tool for hiding activity rather than a guardrail against it.
	.12	Poison AI/ML Training for Evasion	When security monitoring relies on AI/ML (e.g., anomaly detection on telemetry, RF fingerprints, or command semantics), the training data itself is a target. Data-poisoning introduces crafted examples or labels so the learned model embeds false associations, treating attacker behaviors as normal, or flagging benign patterns instead. Variants include clean-label backdoors keyed to subtle triggers, label flipping that shifts decision boundaries, and biased sampling that suppresses rare-but-critical signatures. Models trained on tainted corpora are later deployed as routine updates; once in service, the adversary presents inputs containing the trigger or profile they primed, and the detector omits or downranks the very behaviors that would reveal the intrusion.
DE-0005		Subvert Protections via Safe-Mode	The adversary exploits the spacecraft’s recovery posture to bypass controls that are stricter in nominal operations. During safe-mode, vehicles often accept contingency dictionaries, relax rate/size and timetag checks, activate alternate receivers or antennas, and emit reduced or summary telemetry. By timing actions to this state, or deliberately inducing it, the attacker issues maintenance-looking edits, loads, or mode changes that proceed under broadened acceptance while downlink visibility is thinned. Unauthorized activity blends with anomaly response, evading both automated safeguards and operator suspicion.
DE-0007		Evasion via Rootkit	A rootkit hides malicious activity by interposing on reporting paths after the system has booted. In flight contexts this includes patching flight software APIs, kernel syscalls, message queues, and telemetry publishers so task lists, counters, health channels, and event severities are falsified before downlink. Command handlers can be hooked to suppress evidence of certain opcodes or sources; recorder catalogs and file listings can be rewritten on the fly; and housekeeping can be biased to show nominal temperatures, currents, or voltages while actions proceed. The defining feature is runtime concealment: the observability surfaces operators rely on are altered to present a curated, benign narrative.
DE-0008		Evasion via Bootkit	A bootkit hides activity by running first and shaping what higher layers will later observe. Positioned in boot ROM handoff or early loaders, it can select or patch images in memory, alter device trees and driver tables, seed forged counters and timestamps, and preconfigure telemetry/crypto modes so subsequent components launch into a reality curated by the attacker. Because integrity and logging mechanisms are initialized afterward, the resulting view of processes, files, and histories reflects the bootkit’s choices, allowing long-term evasion that persists across resets and mode transitions.
DE-0010		Overflow Audit Log	The adversary hides activity by exhausting finite on-board logging and telemetry buffers so incriminating events are overwritten before they can be downlinked. Spacecraft typically use ring buffers with severity filters, per-subsystem quotas, and scheduled dump windows; by generating bursts of benign but high-frequency events (file listings, status queries, low-severity housekeeping, repeated mode toggles) or by provoking chatter from chatty subsystems, the attacker accelerates rollover. Variants target recorder indexes and event catalogs so new entries displace older ones, or they align floods with known downlink gaps and pass handovers when retention is shortest. To analysts on the ground, logs appear present but incomplete, showing a plausible narrative that omits the very interval when unauthorized commands or updates occurred.

Space Threats Addressed by Countermeasure

ID	Description
SV-MA-2	Heaters and flow valves of the propulsion subsystem are controlled by electric signals so cyberattacks against these signals could cause propellant lines to freeze, lock valves, waste propellant or even put in de-orbit or unstable spinning
SV-AV-4	Attacking the scheduling table to affect tasking
SV-IT-5	Onboard control procedures (i.e., ATS/RTS) that execute a scripts/sets of commands
SV-MA-3	Attacks on critical software subsystems Attitude Determination and Control (AD&C) subsystem determines and controls the orientation of the satellite. Any cyberattack that could disrupt some portion of the control loop - sensor data, computation of control commands, and receipt of the commands would impact operations Telemetry, Tracking and Commanding (TT&C) subsystem provides interface between satellite and ground system. Computations occur within the RF portion of the TT&C subsystem, presenting cyberattack vector Command and Data Handling (C&DH) subsystem is the brains of the satellite. It interfaces with other subsystems, the payload, and the ground. It receives, validate, decodes, and sends commands to other subsystems, and it receives, processes, formats, and routes data for both the ground and onboard computer. C&DH has the most cyber content and is likely the biggest target for cyberattack. Electrical Power Subsystem (EPS) provides, stores, distributes, and controls power on the satellite. An attack on EPS could disrupt, damage, or destroy the satellite.
SV-SP-1	Exploitation of software vulnerabilities (bugs); Unsecure code, logic errors, etc. in the FSW.
SV-AC-8	Malicious Use of hardware commands - backdoors / critical commands
SV-AV-2	Satellites base many operations on timing especially since many operations are automated. Cyberattack to disrupt timing/timers could affect the vehicle (Time Jamming / Time Spoofing)
SV-AV-3	Affect the watchdog timer onboard the satellite which could force satellite into some sort of recovery mode/protocol
SV-MA-8	Payload (or other component) is told to constantly sense or emit or run whatever mission it had to the point that it drained the battery constantly / operated in a loop at maximum power until the battery is depleted.
SV-AV-5	Using fault management system against you. Understanding the fault response could be leveraged to get satellite in vulnerable state. Example, safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of TLM to cause action from ground, or some sort of RPO to cause S/C to go into safe mode;
SV-DCO-1	Not knowing that you were attacked, or attack was attempted
SV-MA-5	Not being able to recover from cyberattack
SV-CF-1	Tapping of communications links (wireline, RF, network) resulting in loss of confidentiality; Traffic analysis to determine which entities are communicating with each other without being able to read the communicated information
SV-IT-1	Communications system spoofing resulting in denial of service and loss of availability and data integrity
SV-AV-1	Communications system jamming resulting in denial of service and loss of availability and data integrity
SV-MA-6	Not planning for security on SV or designing in security from the beginning

Sample Requirements

SPARTA ID	Requirement	Rationale/Additional Guidance/Notes
SPR-4	The [spacecraft] security implementation shall ensure that information should not be allowed to flow between partitioned applications unless explicitly permitted by the system.{SV-AC-6,SV-MA-3,SV-SP-7}{AC-3(3),AC-3(4),AC-4,AC-4(6),AC-4(21),CA-9,IA-9,SA-8(3),SA-8(18),SA-8(19),SC-2(2),SC-7(29),SC-16,SC-32}	Strict partitioning prevents compromise of one application from cascading into mission-critical subsystems. Many spacecraft attacks exploit flat architectures where subsystems implicitly trust one another. Explicit inter-partition authorization limits lateral movement and privilege escalation. This supports containment and fault isolation under both cyber and fault conditions.
SPR-7	The [organization] shall document and design a security architecture using a defense-in-depth approach that allocates the [organization]s defined safeguards to the indicated locations and layers: [Examples include: operating system abstractions and hardware mechanisms to the separate processors in the platform, internal components, and the FSW].{SV-MA-6}{CA-9,PL-7,PL-8,PL-8(1),SA-8(3),SA-8(4),SA-8(7),SA-8(9),SA-8(11),SA-8(13),SA-8(19),SA-8(29),SA-8(30)}	Spacecraft security cannot rely on a single control; layered defenses reduce the likelihood of catastrophic compromise. Documenting safeguard allocation across hardware, OS, firmware, and FSW ensures coverage across attack surfaces. This supports resiliency against both cyber intrusion and supply chain weaknesses. Clear documentation enables verification and independent assessment.
SPR-8	The [organization] shall ensure that the allocated security safeguards operate in a coordinated and mutually reinforcing manner.{SV-MA-6}{CA-7(5),PL-7,PL-8(1),SA-8(19)}	Independent controls that operate in isolation may create security gaps or conflicting behaviors. Coordinated safeguards ensure that encryption, authentication, partitioning, and monitoring functions reinforce each other rather than undermine availability or safety. This reduces bypass risk and improves fault/cyber response integration. Cohesive operation is essential for resilient mission assurance.
SPR-9	The [organization] shall implement a security architecture and design that provides the required security functionality, allocates security controls among physical and logical components, and integrates individual security functions, mechanisms, and processes together to provide required security capabilities and a unified approach to protection.{SV-MA-6}{PL-7,SA-2,SA-8,SA-8(1),SA-8(2),SA-8(3),SA-8(4),SA-8(5),SA-8(6),SA-8(7),SA-8(9),SA-8(11),SA-8(13),SA-8(19),SA-8(29),SA-8(30),SC-32,SC-32(1)}	Security functionality must be intentionally distributed across physical and logical components rather than bolted on post-design. A unified architecture prevents inconsistent enforcement, duplicated controls, or unprotected interfaces. Integrated design reduces attack surface and improves verification of mission-critical protections.
SPR-14	The [spacecraft] shall authenticate the ground station (and all commands) and other spacecraft before establishing remote connections using bidirectional authentication that is cryptographically based.{SV-AC-1,SV-AC-2}{AC-3,AC-17,AC-17(2),AC-17(10),AC-18(1),AC-20,IA-3(1),IA-4,IA-4(9),IA-7,IA-9,SA-8(18),SA-8(19),SA-9(2),SC-7(11),SC-16(1),SC-16(2),SC-16(3),SC-23(3),SI-3(9)}	Authorization can include embedding opcodes in command strings, using trusted authentication protocols, identifying proper link characteristics such as emitter location, expected range of receive power, expected modulation, data rates, communication protocols, beamwidth, etc.; and tracking command counter increments against expected values.
SPR-15	The [spacecraft] shall implement cryptographic mechanisms to identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.{SV-AV-1,SV-IT-1}{AC-3,AC-20,SA-8(19),SC-8(1),SC-23(3),SC-40(3),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}	Adversaries may attempt imitative RF signals to inject commands or manipulate spacecraft behavior. Signal parameter validation (modulation, power, timing, waveform characteristics) strengthens command authentication beyond cryptographic validation alone. This helps mitigate spoofing, replay, and rogue emitter attacks. RF-layer validation complements cryptographic controls.
SPR-20	The [spacecraft] shall prevent use of a mode of operations where cryptography on the TT&C link can be disabled; encryption and authentication shall remain enabled even when automated access control mechanisms are overridden.{SV-AC-1,SV-CF-1,SV-CF-2}{AC-3(10),SA-8(18),SA-8(19),SC-16(2),SC-16(3),SC-40,SC-40(4)}	Emergency or override modes often become attack vectors if protections are weakened. Cryptography must remain enforced even during safe-mode or degraded operations. Removing encryption capability creates a single-point catastrophic exposure. Persistent protection ensures no operational shortcut undermines mission assurance.
SPR-22	The [spacecraft] shall implement boundary protections to separate bus, communications, and payload components supporting their respective functions.{SV-AC-6}{AC-3(3),AC-3(4),CA-9,SA-8(3),SA-8(14),SA-8(18),SA-8(19),SA-17(7),SC-2,SC-2(2),SC-7(13),SC-7(21),SC-7(29),SC-16(3),SC-32,SI-3,SI-4(13),SI-4(25)}	Flat architectures allow compromise of one subsystem to impact all others. Segregated boundaries reduce lateral movement and mission degradation. Isolation ensures payload compromise does not impact TT&C or bus control. This supports containment and survivability.
SPR-23	The [spacecraft] shall isolate mission critical functionality from non-mission critical functionality.{SV-AC-6}{AC-3(3),AC-3(4),CA-9,SA-8(3),SA-8(19),SA-17(7),SC-2,SC-3,SC-3(4),SC-7(13),SC-7(29),SC-32,SC-32(1),SI-3,SI-7(10),SI-7(12)}	Non-critical functions often expand attack surface. Isolation prevents less-trusted components from affecting propulsion, attitude control, or power systems. This reduces cascading failure risk under compromise. Mission-critical systems must maintain operational continuity.
SPR-28	The [spacecraft] shall provide the capability to enter the platform into a known good, operational cyber-safe mode from a tamper-resistant, configuration-controlled (“gold”) image that is authenticated as coming from an acceptable supplier, and has its integrity verified. The [spacecraft] shall refresh only from cryptographically authenticated [organization]-approved sources.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4(3),SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-13,SI-17}	Cyber-safe mode is an operating mode of a spacecraft during which all nonessential systems are shut down and the spacecraft is placed in a known good state using validated software and configuration settings. Within cyber-safe mode authentication and encryption should still be enabled. The spacecraft should be capable of reconstituting firmware and SW functions to preattack levels to allow for the recovery of functional capabilities. This can be performed by self-healing, or the healing can be aided from the ground. However, the spacecraft needs to have the capability to replan, based on available equipment still available after a cyberattack. The goal is for the vehicle to resume full mission operations. If not possible, a reduced level of mission capability should be achieved.
SPR-29	The [spacecraft] shall enter cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.{CP-10(6),CP-13,SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-17}
SPR-30	The [spacecraft] shall fail to a known secure state for failures during initialization, and aborts preserving information necessary to return to operations in failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-13,SA-8(16),SA-8(19),SA-8(24),SC-24,SI-13,SI-17}
SPR-31	The [spacecraft] shall fail securely to a secondary device in the event of an operational failure of a primary boundary protection device (i.e., crypto solution).{SV-AC-1,SV-AC-2,SV-CF-1,SV-CF-2}{CP-13,SA-8(19),SA-8(24),SC-7(18),SI-13,SI-13(4)}	If a primary boundary protection device fails, the spacecraft must not revert to insecure operation. Secure failover ensures continuity of confidentiality and integrity protections. This prevents adversaries from inducing failure states to bypass encryption. Redundancy strengthens mission resilience.
SPR-32	The [spacecraft] shall provide or support the capability for recovery and reconstitution to a known state after a disruption, compromise, or failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-4(4),CP-10,CP-10(4),CP-10(6),CP-13,IR-4,IR-4(1),SA-8(16),SA-8(19),SA-8(24)}
SPR-33	The [spacecraft] shall utilize TRANSEC. TRANSEC shall be implemented and verified as a distinct layer in coordination with Traffic Flow Security and RF anti‑fingerprinting.{SV-AV-1}{CP-8,RA-5(4),SA-8(18),SA-8(19),SC-8(1),SC-8(4),SC-16,SC-16(1),SC-16(2),SC-16(3),SC-40,SC-40(4)}	Transmission Security (TRANSEC) is used to ensure the availability of transmissions and limit intelligence collection from the transmissions. TRANSEC is secured through burst encoding, frequency hopping, or spread spectrum methods where the required pseudorandom sequence generation is controlled by a cryptographic algorithm and key. Such keys are known as transmission security keys (TSK). The objectives of transmission security are low probability of interception (LPI), low probability of detection (LPD), and antijam which means resistance to jamming (EPM or ECCM).
SPR-34	The [spacecraft] shall recover to a known cyber-safe state when an anomaly is detected.{IR-4,IR-4(1),SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-3,SI-4(7),SI-10(6),SI-13,SI-17}
SPR-35	The [spacecraft] shall perform an orderly, controlled system shut-down to a known cyber-safe state upon receipt of a termination command or condition.{PE-11,PE-11(1),SA-8(16),SA-8(19),SA-8(24),SI-17}
SPR-36	The [spacecraft] shall operate securely in off-nominal power conditions, including loss of power and spurious power transients.{SV-AV-6,SV-MA-2}{PE-11,PE-11(1),SA-8(16),SA-8(19),SI-13,SI-17}	Power anomalies may induce undefined states exploitable by attackers. Cryptographic and security mechanisms must not degrade into insecure configurations during brownout or transient conditions. This mitigates fault-induced bypass attacks. Resilient operation preserves trust chain continuity.
SPR-37	The [spacecraft] shall protect system components, associated data communications, and communication buses in accordance with: (i) national emissions and TEMPEST policies and procedures, and (ii) the security category or sensitivity of the transmitted information, and shall demonstrate compliance via pre‑launch TEMPEST‑like evaluation for co‑located payload configurations.{SV-CF-2,SV-MA-2}{PE-14,PE-19,PE-19(1),RA-5(4),SA-8(18),SA-8(19),SC-8(1)}	The measures taken to protect against compromising emanations must be in accordance with DODD S-5200.19, or superseding requirements. The concerns addressed by this control during operation are emanations leakage between multiple payloads within a single space platform, and between payloads and the bus.
SPR-43	The [spacecraft] shall initialize the platform to a known safe state.{SA-8(19),SA-8(23),SA-8(24),SI-17}
SPR-46	The [spacecraft] shall monitor [Program‑defined telemetry points] for malicious commanding attempts and alert ground operators upon detection.{SV-AC-2,SV-IT-1,SV-DCO-1}{AC-17,AC-17(1),AC-17(10),AU-3(1),RA-10,SC-7,SC-16,SC-16(2),SC-16(3),SI-3(8),SI-4,SI-4(1),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}	Telemetry-based detection enables identification of anomalous command patterns, replay attempts, and injection attacks. Early detection allows rapid containment before mission impact escalates. Onboard monitoring is critical when ground latency limits intervention. This supports proactive defense.
SPR-47	The [spacecraft] shall implement relay and replay-resistant authentication mechanisms for establishing a remote connection.{SV-AC-1,SV-AC-2}{AC-3,IA-2(8),IA-2(9),SA-8(18),SC-8(1),SC-16(1),SC-16(2),SC-23(3),SC-40(4)}	Replay attacks can reuse valid command packets to manipulate spacecraft behavior. Freshness checks, nonces, and sequence enforcement prevent reuse of captured transmissions. Relay resistance mitigates man-in-the-middle exploitation. This protects command integrity over RF links.
SPR-53	The [organization] shall employ automated tools that provide notification to ground operators upon discovering discrepancies during integrity verification.{CM-3(5),CM-6,IR-6,IR-6(2),SA-8(21),SC-51,SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(2)}
SPR-54	The [spacecraft] shall retain the capability to update/upgrade operating systems while on-orbit.{SV-SP-7}{SA-4(5),SA-8(8),SA-8(31),SA-10(2),SI-3}	The operating system updates should be performed using multi-factor authorization and should only be performed when risk of compromise/exploitation of identified vulnerability outweighs the risk of not performing the update.
SPR-56	The [spacecraft] shall provide automated onboard mechanisms that integrate audit review, analysis, and reporting processes to support mission processes for investigation and response to suspicious activities to determine the attack class in the event of a cyber attack.{SV-DCO-1}{AU-6(1),IR-4,IR-4(1),IR-4(12),IR-4(13),PM-16(1),RA-10,SA-8(21),SA-8(22),SC-5(3),SI-3,SI-3(10),SI-4(7),SI-4(24),SI-7(7)}	* Identifying the class (e.g., exfiltration, Trojans, etc.), nature, or effect of cyberattack (e.g., exfiltration, subverted control, or mission interruption) is necessary to determine the type of response. The first order of identification may be to determine whether the event is an attack or a non-threat event (anomaly). The objective requirement would be to predict the impact of the detected signature. * Unexpected conditions can include RF lockups, loss of lock, failure to acquire an expected contact and unexpected reports of acquisition, unusual AGC and ACS control excursions, unforeseen actuator enabling's or actions, thermal stresses, power aberrations, failure to authenticate, software or counter resets, etc. Mitigation might include additional TMONs, more detailed AGC and PLL thresholds to alert operators, auto-capturing state snapshot images in memory when unexpected conditions occur, signal spectra measurements, and expanded default diagnostic telemetry modes to help in identifying and resolving anomalous conditions.
SPR-57	The [spacecraft] shall monitor and collect all onboard cyber- data (from multiple system components), including identification of potential attacks and information about the attack for subsequent analysis.{SV-DCO-1}{AC-6(9),AC-20,AC-20(1),AU-2,AU-12,IR-4,IR-4(1),RA-10,SI-3,SI-3(10),SI-4,SI-4(1),SI-4(2),SI-4(7),SI-4(24)}	The spacecraft will monitor and collect data that provides accountability of activity occurring onboard the spacecraft. Due to resource limitations on the spacecraft, analysis must be performed to determine which data is critical for retention and which can be filtered. Full system coverage of data and actions is desired as an objective; it will likely be impractical due to the resource limitations. “Cyber-relevant data” refers to all data and actions deemed necessary to support accountability and awareness of onboard cyber activities for the mission. This would include data that may indicate abnormal activities, critical configuration parameters, transmissions on onboard networks, command logging, or other such data items. This set of data items should be identified early in the system requirements and design phase. Cyber-relevant data should support the ability to assess whether abnormal events are unintended anomalies or actual cyber threats. Actual cyber threats may rarely or never occur, but non-threat anomalies occur regularly. The ability to filter out cyber threats for non-cyber threats in relevant time would provide a needed capability. Examples could include successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels).
SPR-58	The [spacecraft] shall generate cyber related audit records containing information that establishes what type of event occurred, when the event occurred, where the event occurred, the source of the event, and the outcome of the event. For privileged or hazardous commands, the audit record shall include the approver identifiers and the command identifier.{SV-DCO-1}{AU-3,AU-3(1),AU-12,IR-4,IR-4(1),RA-10,SI-3,SI-3(10),SI-4(7),SI-4(24)}	Detailed audit records are essential for attribution, anomaly detection, and post-incident forensic reconstruction. Capturing what occurred, when, where, and by whom enables rapid differentiation between system fault and adversarial activity. Including approver identifiers for privileged or hazardous commands strengthens accountability and insider threat mitigation. Without complete audit context, recovery and containment decisions may be delayed or misinformed.
SPR-59	The [spacecraft] shall attribute cyber attacks and identify unauthorized use of the platform by downlinking onboard cyber information to the mission ground station within [Program‑defined time ≤ 3 minutes].{SV-DCO-1,SV-IT-1,SV-IT-2}{AU-4(1),IR-4,IR-4(1),IR-4(12),IR-4(13),RA-10,SA-8(22),SI-3,SI-3(10),SI-4,SI-4(5),SI-4(7),SI-4(12),SI-4(24)}	Rapid transmission of cyber-relevant telemetry supports near-real-time ground-based fusion and correlation with enterprise security events. Delayed reporting increases risk of adversary persistence or mission degradation. Early attribution enables containment actions before cascading effects occur. Defined timeliness ensures detection capability aligns with operational tempo.
SPR-60	The [spacecraft] shall integrate cyber related detection and responses with existing fault management capabilities to ensure tight integration between traditional fault management and cyber intrusion detection and prevention.{SV-DCO-1}{AU-6(4),IR-4,IR-4(1),RA-10,SA-8(21),SA-8(26),SC-3(4),SI-3,SI-3(10),SI-4(7),SI-4(13),SI-4(16),SI-4(24),SI-4(25),SI-7(7),SI-13}	The onboard IPS system should be integrated into the existing onboard spacecraft fault management system (FMS) because the FMS has its own fault detection and response system built in. SV corrective behavior is usually limited to automated fault responses and ground commanded recovery actions. Intrusion prevention and response methods will inform resilient cybersecurity design. These methods enable detected threat activity to trigger defensive responses and resilient SV recovery.
SPR-61	The [spacecraft] shall protect information obtained from logging/intrusion-monitoring from unauthorized access, modification, and deletion.{SV-DCO-1}{AU-9,AU-9(3),RA-10,SI-4(7),SI-4(24)}	Monitoring data is a high-value target for attackers seeking to evade detection or erase traces of compromise. Protecting log integrity preserves evidentiary value and detection continuity. Unauthorized modification or deletion could mask malicious behavior or delay response. Cryptographic protection and access controls ensure monitoring mechanisms cannot be silently disabled.
SPR-62	The [spacecraft] shall enter a cyber-safe mode when conditions that threaten the platform are detected, enters a cyber-safe mode of operation with restrictions as defined based on the cyber-safe mode.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4,IR-4(1),IR-4(3),PE-10,RA-10,SA-8(16),SA-8(21),SA-8(24),SI-3,SI-4(7),SI-13,SI-17}	Cyber-safe mode provides a deterministic fallback posture when compromise or anomalous conditions threaten mission integrity. Restricting non-essential functions reduces attack surface and prevents further propagation of malicious activity. Defined restrictions ensure predictable behavior under cyber stress conditions. This supports survivability and controlled recovery rather than uncontrolled degradation.
SPR-63	The [spacecraft] shall be able to locate the onboard origin of a cyber attack and alert ground operators within [Program‑defined time ≤ 3 minutes].{SV-DCO-1}{IR-4,IR-4(1),IR-4(12),IR-4(13),RA-10,SA-8(22),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(16),SI-4(24)}	The origin of any attack onboard the vehicle should be identifiable to support mitigation. At the very least, attacks from critical element (safety-critical or higher-attack surface) components should be locatable quickly so that timely action can occur.
SPR-64	The [spacecraft] shall detect and deny unauthorized outgoing communications posing a threat to the spacecraft.{SV-DCO-1}{IR-4,IR-4(1),RA-5(4),RA-10,SC-7(9),SC-7(10),SI-4,SI-4(1),SI-4(4),SI-4(7),SI-4(11),SI-4(13),SI-4(24),SI-4(25)}	Outbound communications may indicate data exfiltration, covert channels, or compromised subsystem behavior. Monitoring and blocking unauthorized egress prevents leakage of mission data or cryptographic material. Many attacks rely on command-and-control or data extraction channels; egress control disrupts this persistence mechanism. Outbound traffic should be as tightly controlled as inbound command paths.
SPR-65	The [spacecraft] shall select and execute safe countermeasures against cyber attacks prior to entering cyber-safe mode.{SV-DCO-1}{IR-4,RA-10,SA-8(21),SA-8(24),SI-4(7),SI-17}	These countermeasures are a ready supply of options to triage against the specific types of attack and mission priorities. Minimally, the response should ensure vehicle safety and continued operations. Ideally, the goal is to trap the threat, convince the threat that it is successful, and trace and track the attacker exquisitely—with or without ground aiding. This would support successful attribution and evolving countermeasures to mitigate the threat in the future. “Safe countermeasures” are those that are compatible with the system’s fault management system to avoid unintended effects or fratricide on the system." These countermeasures are likely executed prior to entering into a cyber-safe mode.
SPR-66	The [spacecraft] shall be designed and configured so that encrypted communications traffic and data is visible to on-board security monitoring tools.{SV-DCO-1}{RA-10,SA-8(21),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(10),SI-4(13),SI-4(24),SI-4(25)}	Encryption must not blind onboard intrusion detection capabilities. Security tools require access to sufficient context (pre-encryption or post-decryption inspection points) to detect malicious patterns. Without visibility, encrypted channels become covert channels. Proper architectural placement ensures both confidentiality and detectability are preserved.
SPR-68	The [spacecraft] shall have on-board intrusion detection/prevention system that monitors the mission critical components or systems.{SV-AC-1,SV-AC-2,SV-MA-4}{RA-10,SC-7,SI-3,SI-3(8),SI-4,SI-4(1),SI-4(7),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}	The mission critical components or systems could be GNC/Attitude Control, C&DH, TT&C, Fault Management.
SPR-69	The [spacecraft] shall alert in the event of the audit/logging processing failures.{SV-DCO-1}{AU-5,AU-5(1),AU-5(2),SI-3,SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(24)}	Failure of logging mechanisms may signal active tampering or resource exhaustion attacks. Immediate alerting ensures loss of visibility does not go unnoticed. Silent failure of audit systems creates blind spots exploitable by adversaries. Monitoring the monitors is critical to resilient detection.
SPR-70	The [spacecraft] shall provide an alert immediately to [at a minimum the mission director, administrators, and security officers] when the following failure events occur: [minimally but not limited to: auditing software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity reaching 95%, 99%, and 100%] of allocated capacity, including security component failover events; alerts shall include component identity, time, and fault reason.{SV-DCO-1}{AU-5,AU-5(1),AU-5(2),SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(24),SI-7(7)}	Intent is to have human on the ground be alerted to failures. This can be decomposed to SV to generate telemetry and to Ground to alert.
SPR-71	The [spacecraft] shall provide the capability of a cyber “black-box” to capture necessary data for cyber forensics of threat signatures and anomaly resolution when cyber attacks are detected. The [spacecraft] shall automatically route audit events to the alternate audit logging capability upon primary audit failure and shall resynchronize the alternate store to the primary upon recovery.{SV-DCO-1}{AU-5(5),AU-9(2),AU-9(3),AU-12,IR-4(12),IR-4(13),IR-5(1),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(7),SI-4(24),SI-7(7)}	Similar concept of a "black box" on an aircraft where all critical information is stored for post forensic analysis. Black box can be used to record CPU utilization, GNC physical parameters, audit records, memory contents, TT&C data points, etc. The timeframe is dependent upon implementation but needs to meet the intent of the requirement. For example, 30 days may suffice.
SPR-72	The [spacecraft] shall automatically notify ground operators when onboard integrity verification detects discrepancies.{SV-IT-2}{CM-3(5),SA-8(21),SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(2),SI-7(12)}	Integrity check failures may indicate unauthorized modification, corruption, or hardware faults induced by malicious activity. Automatic notification ensures ground teams can rapidly assess risk and initiate recovery procedures. Delay in reporting increases mission impact. Transparency between onboard detection and ground response is essential for coordinated defense.
SPR-73	The [spacecraft], upon detection of a potential integrity violation, shall provide the capability to [audit the event and alert ground operators].{SV-DCO-1}{CM-3(5),SA-8(21),SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(8)}	One example would be for bad commands where the system would reject the command and not increment the Vehicle Command Counter (VCC) and include the information in telemetry.
SPR-74	The [organization] shall define the security safeguards that are to be automatically employed when integrity violations are discovered.{SV-IT-2}{CP-2,SA-8(21),SI-3,SI-4(7),SI-4(12),SI-7(5),SI-7(8)}	Predefined safeguards ensure consistent and timely response to detected integrity violations. Ad hoc response increases uncertainty and recovery time. Automated actions may include isolation, reconstitution from gold images, or transition to cyber-safe mode. Defined response paths improve resilience and reduce operator burden during crisis.
SPR-78	The [spacecraft] shall provide independent mission/cyber critical threads such that any one credible event will not corrupt another mission/cyber critical thread.{SV-AC-6,SV-MA-3,SV-SP-7}{SC-3,SC-32,SC-32(1),SI-3,SI-13}	Segregating mission-critical and cyber-critical execution paths prevents a single failure or compromise from corrupting other critical functions. Thread independence supports fault containment and resilience under attack. This ensures availability of essential functions even during partial compromise. Isolation strengthens both safety and cybersecurity.
SPR-87	The [spacecraft] shall be configured to provide only essential capabilities.{SV-SP-7,SV-SP-1}{CM-6,CM-7,SA-8(2),SA-8(7),SA-8(13),SA-8(23),SA-8(26),SA-15(5)}	Minimizing enabled functionality reduces attack surface and complexity. Unused services create unnecessary exposure. Essential-only configuration aligns with least functionality principles. This simplifies validation and reduces exploit vectors.
SPR-88	The [spacecraft] shall detect and recover from detected memory errors or transitions to a known cyber-safe state.{SV-IT-4,SV-AV-6}{IR-4,IR-4(1),SA-8(16),SA-8(24),SI-3,SI-4(7),SI-10(6),SI-13,SI-17}	Memory corruption may result from radiation, fault injection, or malicious manipulation. Detection prevents silent data corruption from propagating to mission-critical functions. Recovery mechanisms or safe-state transitions preserve availability. Rapid containment supports mission survivability.
SPR-97	All [spacecraft] commands which have unrecoverable consequence must have dual authentication prior to command execution. The [spacecraft] shall verify two independent cryptographic approvals prior to execution and shall generate an audit record binding both approver identifiers to the command identifier, time, and outcome.{SV-AC-4,SV-AC-8,SV-AC-2}{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13}	Commands with irreversible impact require heightened assurance to prevent catastrophic mission loss. Dual independent cryptographic approvals mitigate insider threat, key compromise, and single-point credential abuse. Binding approver identifiers to the audit trail strengthens accountability and deterrence. This reduces the probability of unauthorized hazardous command execution.
SPR-98	The [spacecraft] shall have a method to ensure the integrity of which have unrecoverable consequence and validate their authenticity before execution.{SV-AC-2,SV-IT-2,SV-IT-1}{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13}	Hazardous commands must be cryptographically protected and validated prior to execution. Integrity and authenticity checks prevent replay, modification, or injection of destructive instructions. Without validation, RF interception or command path compromise could result in mission-ending actions. This ensures critical commands are both authorized and unaltered.
SPR-99	The [spacecraft] shall recover from cyber-safe mode to mission operations within 20 minutes.{SV-MA-5}{CP-2(3),CP-2(5),IR-4,SA-8(24)}	Upon conclusion of addressing the threat, the system should be capable of recovering from the minimal survival mode back into a mission-ready state within defined timelines. The intent is to define the timelines and the capability to return back to mission operations.
SPR-105	The [spacecraft] shall provide two independent and unique command messages to deactivate a fault tolerant capability for a critical or catastrophic hazard.{AC-3(2),PE-10,SA-8(15)}
SPR-106	The [spacecraft] shall provide non-identical methods, or functionally independent methods, for commanding a mission critical function when the software is the sole control of that function.{AC-3(2),SI-3(8),SI-13}
SPR-107	The [spacecraft] shall have multiple uplink paths {SV-AV-1}{CP-8,CP-11,SA-8(18),SC-5,SC-47}	Redundant uplink paths preserve command capability during jamming, interference, or subsystem failure. Availability is a core mission assurance objective. Diverse communication channels reduce single-point failure risk. This enhances resiliency in contested RF environments.
SPR-109	The [spacecraft] shall be constructed with electromagnetic shielding to protect electronic components from damage to the degree deemed acceptable. Verification for EMP/HANE shall be distinct from EMSEC/TEMPEST, anti‑jam/anti‑spoof, and EMI/EPM protections.{SV-MA-2,SV-IT-4}{PE-9,PE-14,PE-18,PE-21}	EMP and HANE events can induce systemic failures independent of cyber exploitation. Shielding protects electronics from catastrophic damage and fault-induced vulnerabilities. Distinguishing EMP/HANE from EMSEC and anti-jam ensures correct threat modeling and verification. Physical resilience complements cyber defenses.
SPR-113	The [spacecraft] shall implement protections against external and internal communications from jamming attempts; verification for anti‑jam shall be distinct from EMI/EPM, EMP/HANE hardness, and anti‑spoof protections.{SV-AV-1}{SC-5,SC-40,SC-40(1)}	Jamming disrupts availability and can mask other malicious activities. Dedicated anti-jam mechanisms preserve command and telemetry continuity. Distinguishing from EMI/EPM and anti-spoof ensures comprehensive RF threat coverage. Availability protections must be validated independently.
SPR-114	The [spacecraft] shall protect external and internal communications from jamming and spoofing attempts; verification for anti‑spoof shall be distinct from EMI/EPM and EMP/HANE hardness.{SV-AV-1,SV-IT-1}{SC-5,SC-40,SC-40(1)}	Can be aided via the Crosslink, S-Band, and L-Band subsystems
SPR-117	The [spacecraft] shall provide the capability to restrict command lock based on geographic location of ground stations.{SV-AC-1}{AC-2(11),IA-10,SI-4(13),SI-4(25)}	This could be performed using command lockout based upon when the spacecraft is over selected regions. This should be configurable so that when conflicts arise, the Program can update. The goal is so the spacecraft won't accept a command when the spacecraft determines it is in a certain region.
SPR-130	The [spacecraft] shall discriminate between valid and invalid input into the software and rejects invalid input.{SV-SP-1,SV-IT-2}{SC-16(2),SI-3(8),SI-10,SI-10(3),SI-10(6)}	Input validation prevents buffer overflows, injection, and parser exploitation. Rejecting malformed or unexpected data reduces denial-of-service and corruption risks. Deterministic validation improves resilience. Robust input handling is fundamental to secure software.
SPR-131	The [spacecraft] shall identify and reject commands received out-of-sequence when the out-of-sequence commands can cause a hazard/failure or degrade the control of a hazard or mission.{SV-AC-2,SV-AV-4}{SC-16(2),SI-4(13),SI-4(25),SI-10,SI-10(6),SI-13}	Command sequencing enforces operational logic and safety interlocks. Out-of-sequence commands may bypass safeguards. Sequence enforcement prevents replay and control manipulation. This preserves control flow integrity.
SPR-141	The [spacecraft] shall perform prerequisite checks for the execution of hazardous commands.{SI-10,SI-10(6),SI-13}
SPR-144	The [spacecraft] shall validate a functionally independent parameter prior to the issuance of any sequence that could remove an inhibit, or perform a hazardous action.{SV-AC-8,SV-MA-3}{SI-10(3),SI-10(6),SI-13}	Redundant validation mechanisms ensure hazardous transitions cannot occur through single-point compromise. Independent parameters strengthen control integrity. This reduces exploit paths for inhibit removal. Critical operations demand dual validation logic.
SPR-186	The [spacecraft] shall have fault-tolerant authoritative time sourcing for the platform's clock.{SV-IT-1}{AU-8(2),SC-45,SC-45(1),SC-45(2),SI-13}	* Adopt voting schemes (triple modular redundancy) that include inputs from backup sources. Consider providing a second reference frame against which short-term changes or interferences can be compared. * Atomic clocks, crystal oscillators and/or GPS receivers are often used as time sources. GPS should not be used as the only source due to spoofing/jamming concerns.
SPR-202	The [organization] shall define the security safeguards to be employed to protect the availability of system resources.{SV-AC-6}{SC-6,SI-17}	Explicit availability planning ensures defensive resources are provisioned. Clear safeguards prevent ad hoc reactions during incidents. Structured resilience planning supports mission assurance. Availability is often a primary operational objective.
SPR-203	The [spacecraft] shall have failure tolerance on sensors used by software to make mission-critical decisions.{SV-MA-3,SV-AV-7}{SI-13,SI-17}	Sensor compromise or failure must not directly lead to hazardous action. Redundancy and validation ensure trustworthy inputs. Independent verification reduces risk of manipulation. Critical decisions require reliable sensing.
SPR-204	The [spacecraft] cyber-safe mode software/configuration shall be stored onboard the spacecraft in memory with hardware-based controls and shall not be modifiable.{SV-AV-5,SV-AV-6,SV-AV-7}{SI-17}	Cyber-safe mode is using a fail-secure mentality where if there is a malfunction that the spacecraft goes into a fail-secure state where cyber protections like authentication and encryption are still employed (instead of bypassed) and the spacecraft can be restored by authorized commands. The cyber-safe mode should be stored in a high integrity location of the on-board SV so that it cannot be modified by attackers.
SPR-205	The [spacecraft] shall safely transition between all predefined, known states.{SV-AV-5,SV-AV-3,SV-AV-6}{SI-17}	Deterministic transitions prevent undefined or unstable states. Controlled state management limits exploitation windows. Safety logic must anticipate abnormal conditions. Predictable behavior enhances resilience.
SPR-206	The [spacecraft] software subsystems shall detect and recover/transition from detected memory errors to a known cyber-safe state.{SV-MA-3,SV-AV-7}{SI-17}	Memory corruption can degrade or hijack execution. Automated detection and transition to safe state prevents escalation. Recovery mechanisms reduce persistent compromise risk. Resilience requires automatic containment.
SPR-207	The [spacecraft] software subsystems shall initialize the spacecraft to a known safe state.{SV-MA-3,SV-AV-7}{SI-17}	Startup is a vulnerable period for tampering. Initialization ensures clean baseline before operations begin. Safe defaults prevent unauthorized persistence. Boot integrity establishes trust.
SPR-208	The [spacecraft] software subsystems shall operate securely in off-nominal power conditions, including loss of power and spurious power transients.{SV-MA-3,SV-AV-7}{SI-17}	Power instability may disrupt security controls. Robust design prevents exploit via induced power anomalies. Controlled behavior during transients preserves integrity. Cyber resilience must consider physical fault conditions.
SPR-209	The [spacecraft] software subsystems shall perform an orderly, controlled system shutdown to a known cyber-safe state upon receipt of a termination command or condition.{SV-MA-3,SV-AV-7}{SI-17}	Graceful shutdown prevents data corruption and incomplete processes. Controlled transitions reduce recovery complexity. Secure shutdown blocks adversary exploitation during failure states. Predictable termination supports resilience.
SPR-210	The [spacecraft] software subsystems shall recover to a known cyber-safe state when an anomaly is detected.{SV-MA-3,SV-AV-7}{SI-17}	Anomaly-triggered containment reduces attacker dwell time. Safe fallback states preserve mission viability. Autonomous response is essential given communication latency. Rapid isolation prevents lateral spread.
SPR-211	The [spacecraft] software subsystems shall safely transition between all predefined, known states.{SV-MA-3,SV-AV-7}{SI-17}	Safe and deterministic state transitions prevent undefined behavior that could be exploited during abnormal or adversarial conditions. Many cyber and fault-based attacks attempt to force systems into unexpected transitional states where validation checks may be bypassed. By ensuring transitions only occur along predefined, verified paths, the spacecraft reduces opportunities for logic corruption or hazardous command execution. Controlled state management strengthens both safety assurance and cybersecurity resilience.
SPR-212	The [spacecraft] shall be capable of shutting off specific subsystems or payloads to isolate malicious activity or protect the platform.{SV-MA-3,SV-AC-6,SV-SP-3,SV-MA-8}{PE-10}	Isolation limits impact of compromised components. Segmentation prevents systemic compromise. Controlled shutdown preserves overall platform health. Modular containment strengthens survivability.
SPR-229	The [organization] shall protect documentation and Controlled Unclassified Information (CUI) as required, in accordance with the risk management strategy.{SV-CF-3,SV-SP-4,SV-SP-10}{AC-3,CM-12,CP-2,PM-17,RA-5(4),SA-3,SA-3(1),SA-5,SA-10,SC-8(1),SC-28(3),SI-12}	Documentation may reveal architecture details exploitable by adversaries. Proper handling prevents leakage. Protection of CUI supports regulatory compliance. Information governance complements technical controls.
SPR-230	The [organization] shall identify and properly classify mission sensitive design/operations information and access control shall be applied in accordance with classification guides and applicable federal laws, Executive Orders, directives, policies, regulations, and standards.{SV-CF-3,SV-AV-5}{AC-3,CM-12,CP-2,PM-17,RA-5(4),SA-3,SA-3(1),SA-5,SA-8(19),SC-8(1),SC-28(3),SI-12}	* Mission sensitive information should be classified as Controlled Unclassified Information (CUI) or formally known as Sensitive but Unclassified. Ideally these artifacts would be rated SECRET or higher and stored on classified networks. Mission sensitive information can typically include a wide range of candidate material: the functional and performance specifications, the RF ICDs, databases, scripts, simulation and rehearsal results/reports, descriptions of uplink protection including any disabling/bypass features, failure/anomaly resolution, and any other sensitive information related to architecture, software, and flight/ground /mission operations. This could all need protection at the appropriate level (e.g., unclassified, SBU, classified, etc.) to mitigate levels of cyber intrusions that may be conducted against the project’s networks. Stand-alone systems and/or separate database encryption may be needed with controlled access and on-going Configuration Management to ensure changes in command procedures and critical database areas are tracked, controlled, and fully tested to avoid loss of science or the entire mission.
SPR-231	The [organization] shall distribute documentation to only personnel with defined roles and a need to know.{SV-CF-3,SV-AV-5}{CM-12,CP-2,SA-5,SA-10}	Least privilege and need to know should be employed with the protection of all documentation. Documentation can contain sensitive information that can aid in vulnerability discovery, detection, and exploitation. For example, command dictionaries for ground and space systems should be handles with extreme care. Additionally, design documents for missions contain many key elements that if compromised could aid in an attacker successfully exploiting the system.
SPR-232	The [organization] shall conduct a criticality analysis to identify mission critical functions and critical components and reduce the vulnerability of such functions and components through secure system design.{SV-SP-3,SV-SP-4,SV-AV-7,SV-MA-4}{CP-2,CP-2(8),PL-7,PM-11,PM-30(1),RA-3(1),RA-9,SA-8(9),SA-8(11),SA-8(25),SA-12,SA-14,SA-15(3),SC-7(29),SR-1}	During SCRM, criticality analysis will aid in determining supply chain risk. For mission critical functions/components, extra scrutiny must be applied to ensure supply chain is secured.
SPR-233	The [organization] shall identify the applicable physical and environmental protection policies covering the development environment and spacecraft hardware. {SV-SP-4,SV-SP-5,SV-SP-10}{PE-1,PE-14,SA-3,SA-3(1),SA-10(3)}	Development environments must be protected from tampering. Physical controls prevent hardware supply chain compromise. Policy clarity ensures consistent safeguards. Secure development underpins secure deployment.
SPR-234	The [organization] shall develop and document program-specific identification and authentication policies for accessing the development environment and spacecraft. {SV-SP-10,SV-AC-4}{AC-3,AC-14,IA-1,SA-3,SA-3(1)}	Strong authentication prevents unauthorized development access. Development compromise can introduce malicious code. Documented policies ensure consistent enforcement. Identity governance supports supply chain integrity.
SPR-235	The [organization] shall ensure security requirements/configurations are placed in accordance with NIST 800-171 with enhancements in 800-172 on the development environments to prevent the compromise of source code from supply chain or information leakage perspective.{SV-SP-4,SV-SP-10,SV-CF-3}{AC-3,SA-3,SA-3(1),SA-15}	Supply chain threats target development environments. Enhanced controls reduce risk of source code exfiltration. Compliance strengthens contractual and regulatory assurance. Development security directly impacts spacecraft integrity.
SPR-236	The [organization] shall implement a verifiable flaw remediation process into the developmental and operational configuration management process.{SV-SP-1,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CA-2,CA-5,SA-3,SA-3(1),SA-11,SI-3,SI-3(10)}	The verifiable process should also include a cross reference to mission objectives and impact statements. Understanding the flaws discovered and how they correlate to mission objectives will aid in prioritization.
SPR-237	The [organization] shall establish robust procedures and technical methods to perform testing to include adversarial testing (i.e.abuse cases) of the platform hardware and software.{SV-SP-2,SV-SP-1}{CA-8,CP-4(5),RA-5,RA-5(1),RA-5(2),SA-3,SA-4(3),SA-11,SA-11(1),SA-11(2),SA-11(5),SA-11(7),SA-11(8),SA-15(7)}	Abuse-case testing reveals design weaknesses before deployment. Red-teaming strengthens defensive posture. Proactive validation reduces operational risk. Testing must simulate realistic threat scenarios.
SPR-238	The [organization] shall require subcontractors developing information system components or providing information system services (as appropriate) to demonstrate the use of a system development life cycle that includes [state-of-the-practice system/security engineering methods, software development methods, testing/evaluation/validation techniques, and quality control processes].{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-9}{SA-3,SA-4(3)}	Select the particular subcontractors, software vendors, and manufacturers based on the criticality analysis performed for the Program Protection Plan and the criticality of the components that they supply. Examples of good security practices would be using defense-in-depth tactics across the board, least-privilege being implemented, two factor authentication everywhere possible, using DevSecOps, implementing and validating adherence to secure coding standards, performing static code analysis, component/origin analysis for open source, fuzzing/dynamic analysis with abuse cases, etc.
SPR-245	The [organization] shall define processes and procedures to be followed when integrity verification tools detect unauthorized changes to software, firmware, and information.{SV-IT-2}{CM-3,CM-3(1),CM-3(5),CM-5(6),CM-6,CP-2,IR-6,IR-6(2),PM-30,SC-16(1),SC-51,SI-3,SI-4(7),SI-4(24),SI-7,SI-7(7),SI-7(10)}	Predefined response procedures reduce reaction time. Clear escalation paths improve containment. Consistent handling prevents confusion during incidents. Preparedness strengthens resilience.
SPR-253	The [organization] shall coordinate penetration testing on mission critical spacecraft components (hardware and/or software).{SV-MA-4}{CA-8,CA-8(1),CP-4(5)}	Not all defects (i.e., buffer overflows, race conditions, and memory leaks) can be discovered statically and require execution of the system. This is where space-centric cyber testbeds (i.e., cyber ranges) are imperative as they provide an environment to maliciously attack components in a controlled environment to discover these undesirable conditions. Technology has improved to where digital twins for spacecraft are achievable, which provides an avenue for cyber testing that was often not performed due to perceived risk to the flight hardware.
SPR-259	The [organization] shall develop an incident response and forensics plan that covers the spacecrafts.{SV-MA-5}{CP-2,IR-1,IR-3,IR-3(2),IR-4(12),IR-4(13),IR-8,SA-15(10),SI-4(24)}	A structured response plan enables coordinated containment and recovery. Forensics planning ensures evidence preservation. Defined procedures reduce confusion during crisis. Incident readiness enhances resilience.
SPR-260	The [organization] shall test the incident response capabilities of the spacecraft to determine the effectiveness of the plan and readiness to execute the plan.{SV-MA-5}{IR-3}	Practical exercises validate plan effectiveness. Testing ensures spacecraft systems can support containment, telemetry capture, and recovery actions. Simulation reduces uncertainty during real events. Readiness must be demonstrated, not assumed.
SPR-261	The [organization] shall coordinate testing of the incident response plan with organizational elements responsible for related plans.{SV-MA-5}{IR-3(2)}	Cyber incidents span mission, enterprise, and supplier boundaries. Coordinated exercises ensure interoperability and shared understanding. Integrated testing reduces response friction. Cross-organizational alignment improves containment.
SPR-280	The [organization] shall require the developer of the system, system component, or system service to deliver the system, component, or service with [Program-defined security configurations] implemented.{SV-SP-1,SV-SP-9}{SA-4(5)}	For the spacecraft FSW, the defined security configuration could include to ensure the software does not contain a pre-defined list of Common Weakness Enumerations (CWEs)and/or CAT I/II Application STIGs.
SPR-292	The [organization] shall ensure that role-based security-related training is provided to personnel with assigned security roles and responsibilities: (i) before authorizing access to the system or performing assigned duties; (ii) when required by system changes; and (iii) at least annually thereafter.{SV-AC-4}{AT-3,CP-2}	Personnel must understand role-specific responsibilities. Tailored training reduces misuse. Continuous reinforcement maintains awareness. Human factors are central to defense.
SPR-293	The [organization] shall employ techniques to limit harm from potential adversaries identifying and targeting the [organization]s supply chain.{SV-SP-4,SV-SP-5,SV-SP-6}{CP-2,PM-30,SA-9,SA-12(5),SC-38,SR-3,SR-3(1),SR-3(2),SR-5(2)}	Adversaries often exploit supplier relationships. Protective measures reduce reconnaissance and manipulation. Supply chain resilience strengthens mission integrity. Proactive defense mitigates systemic exposure.
SPR-299	The [organization] shall develop, document, and maintain under configuration control, a current baseline configuration of the spacecrafts.{SV-SP-9,SV-MA-6}{CM-2,CM-3(7),CM-4(2),CM-6,SA-8(30),SA-10}	Configuration control ensures traceability of hardware and software states. Unauthorized changes undermine security posture. Accurate baselines enable recovery and audit. Governance depends on configuration integrity.
SPR-300	The [organization] shall maintain the integrity of the mapping between the master build data (hardware drawings and software/firmware code) describing the current version of hardware, software, and firmware and the on-site master copy of the data for the current version.{SV-SP-4,SV-SP-9}{CM-6,SA-8(21),SA-8(30),SA-10,SA-10(3),SA-10(4),SA-10(5),SI-7(10),SR-4(4)}	Build data linkage ensures reproducibility and traceability. Tampering detection depends on accurate mapping. Integrity of master copies prevents unauthorized modification. Configuration discipline supports resilience.
SPR-301	The [organization] shall develop a security plan for the spacecraft.{SV-MA-6}{PL-2,PL-7,PM-1,SA-8(29),SA-8(30)}	A comprehensive security plan aligns controls with mission objectives. Clear articulation ensures consistent implementation. Planning integrates security into operations. Formal documentation strengthens accountability.
SPR-302	The [organization] shall document the platform's security architecture, and how it is established within and is an integrated part of the overall [organization] mission security architecture.{SV-MA-6,SV-MA-4}{PL-7,SA-8(7),SA-8(13),SA-8(29),SA-8(30),SA-17}	Architecture documentation provides structural clarity. Integration into enterprise mission security ensures alignment. Clear documentation reduces misinterpretation. Transparency strengthens lifecycle governance.
SPR-357	The [organization] defines the security safeguards to be employed to protect the availability of system resources.{CP-2(2),SC-6,SI-13,SI-17}
SPR-408	The [organization] shall produce a plan for the continuous monitoring of security control effectiveness. The plan shall explicitly cover the space platform and link segment telemetry, automated anomaly detection, and SOC correlation of uplink, crosslink, and payload communications.{SV-DCO-1,SV-IT-1,SV-AV-1}{SA-4(8),CP-4(5),PM-31}	Comprehensive coverage ensures both onboard and communication segments are monitored. Telemetry-driven detection strengthens anomaly awareness. SOC correlation integrates space and ground visibility. Structured planning enhances detection capability.
SPR-435	For FPGA pre-silicon artifacts that are developed, coded, and tested by a developer that is not accredited, the [organization] shall be subjected to a development environment and pre-silicon artifacts risk assessment by [organization]. Based on the results of the risk assessment, the [organization] may need to implement protective measures or other processes to ensure the integrity of the FPGA pre-silicon artifacts.{SV-SP-5}{SA-3,SA-3(1),SA-8(9),SA-8(11),SA-12,SA-12(1),SR-1,SR-5}	DOD-I-5200.44 requires the following: 4.c.2 “Control the quality, configuration, and security of software, firmware, hardware, and systems throughout their lifecycles... Employ protections that manage risk in the supply chain… (e.g., integrated circuits, field-programmable gate arrays (FPGA), printed circuit boards) when they are identifiable (to the supplier) as having a DOD end-use. “ 4.e “In applicable systems, integrated circuit-related products and services shall be procured from a Trusted supplier accredited by the Defense Microelectronics Activity (DMEA) when they are custom-designed, custommanufactured, or tailored for a specific DOD military end use (generally referred to as application-specific integrated circuits (ASIC)). “ 1.g “In coordination with the DOD CIO, the Director, Defense Intelligence Agency (DIA), and the Heads of the DOD Components, develop a strategy for managing risk in the supply chain for integrated circuit-related products and services (e.g., FPGAs, printed circuit boards) that are identifiable to the supplier as specifically created or modified for DOD (e.g., military temperature range, radiation hardened).
SPR-436	The [organization] shall require the developer of the system, system component, or system services to demonstrate the use of a system development life cycle that includes [state-of-the-practice system/security engineering methods, software development methods, testing/evaluation/validation techniques, and quality control processes].{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-9}{SA-3,SA-4(3)}	Examples of good security practices would be using defense-in-depth tactics across the board, least-privilege being implemented, two factor authentication everywhere possible, using DevSecOps, implementing and validating adherence to secure coding standards, performing static code analysis, component/origin analysis for open source, fuzzing/dynamic analysis with abuse cases, etc.
SPR-479	The [organization] shall define, baseline, and maintain the purposing of the space platform and link segment, including intended objectives, authorized capabilities, prohibited functions, and operational constraints, and shall use this baseline to bound requirements, updates, and on-orbit operations.{SV-AC-8,SV-MA-6}{PM-32,PL-8}	Defining authorized and prohibited functions prevents scope creep. Clear purposing bounds updates and operational use. Governance limits misuse potential. Structured baseline supports disciplined operations.
SPR-493	The [spacecraft] shall ensure that security-critical functions, including cryptographic processing, key storage, secure boot, and audit logging, continue under single-component failure by providing redundancy, graceful degradation, or verified fallback modes.{SV-MA-5}{SI-13,SC-24}	Single-point failure in security undermines mission assurance. Redundancy ensures continued enforcement. Graceful degradation maintains CIA protections. Fault tolerance supports resilience.
SPR-494	The [spacecraft] shall preserve and protect a golden backup of security credentials and integrity anchors and shall restore them automatically when corruption is detected.{SV-AC-3,SV-IT-3}{SI-13,CP-9}	Protected backups enable secure recovery from corruption. Automatic restoration reduces downtime. Integrity anchors preserve trust. Backup governance strengthens resilience.
SPR-495	The [spacecraft] shall detect impending failure of security components and initiate controlled failover to preserve confidentiality, integrity, and availability.{SV-MA-5,SV-DCO-1}{SI-4,SI-13,CP-10}	Early detection prevents cascading compromise. Controlled switchover maintains CIA properties. Structured alerting enhances situational awareness. Fault handling preserves assurance.
SPR-496	The [spacecraft] shall provide standby instances for [organization]-defined high-criticality security components and automatically switch to the standby upon failure detection, generating an immediate alert that includes the component identity, time, and fault reason.{SV-MA-5}{SI-13(4),CP-10,AU-5}	Automatic failover reduces human delay. Immediate alerts support oversight. Identity and fault logging strengthen accountability. Resilient architecture supports mission continuity.
SPR-497	The [spacecraft] shall verify the standby component integrity before activation using stored signatures and shall revert if verification fails.{SV-SP-4,SV-AC-3}{SI-13(4)}	Failover to compromised standby defeats purpose. Signature verification ensures trust continuity. Reversion prevents propagation of corruption. Validation strengthens resilience.
SPR-530	The [spacecraft] shall enable selected maintenance capabilities only within time‑bounded and mode‑bounded windows, audit enable/disable events, auto‑revert on timeout/reset, and expose enabled/disabled capability state in telemetry.{SV-AC-8,SV-AC-4}{CM-7,CM-7(2),SA-8,SA-8(14),AC-3}	Maintenance capabilities expand risk surface. Time-limited activation reduces abuse window. Telemetry exposure ensures oversight. Auto-revert strengthens containment.
SPR-538	The [spacecraft] shall budget CPU/power/memory for security functions (crypto, logging, verification), implement graceful degradation (e.g., summarize logs, throttle verification) that preserves TT&C and safing, and expose telemetry showing throttling decisions and residual capacity.{SV-AV-1,SV-DCO-1}{PE-9,SA-8(8),SC-6,CP-2}	Security must not starve essential TT&C. Explicit resource budgeting ensures sustained enforcement. Graceful degradation preserves mission priority. Telemetry visibility supports oversight.
SPR-540	The [spacecraft] shall employ deterministic scheduling where feasible and bound retries/timeouts on command/telemetry paths by mode, exposing retry counters, backoff state, and finite‑state transitions in telemetry with consistent error/reject reason codes.{SV-IT-4,SV-AV-1}{SA-8(12),SI-10(3),SI-13}	Determinism prevents runaway retries or timing exploitation. Exposed counters support diagnosis. Finite-state transitions strengthen transparency. Predictable behavior improves assurance.
SPR-541	The [spacecraft] shall provide a trusted path for sensitive actions (e.g., key management, image activation) with strengthened authentication/integrity checks, narrow interfaces, and explicit telemetry cues (trusted‑path active, preconditions satisfied); operations shall confirm trusted‑path use before proceeding.{SV-AC-1,SV-SP-9}{SA-8(13),SC-11,SC-12}	Narrow interfaces reduce attack vectors. Explicit trusted-path indicators prevent misuse. Strengthened authentication protects critical operations. Procedural confirmation ensures compliance.
SPR-542	The [spacecraft] shall reserve CPU/memory/link budget for essential TT&C (command authentication, attitude/power control loops, critical telemetry) and preempt/shape payload and nonessential traffic under stress.{SV-AV-1,SV-AC-8}{SC-5,SC-5(2),SC-6,CP-10}	Command authentication and attitude control may take precedence. Traffic shaping prevents payload starvation attacks. Priority enforcement preserves safe operations. Resource governance strengthens availability.
SPR-550	The [spacecraft] shall provide authenticated, auditable commands to inhibit or narrow subsystems/functions without risking loss of recovery paths, with explicit telemetry confirming resultant state; ground systems shall provide authenticated RF‑transmitter inhibits and rack‑level power controls with audit.{SV-AC-8,SV-MA-7}{PE-10,AC-6,AC-6(5),IA-2}	Controlled inhibit functions enable safe containment. Explicit telemetry confirms resultant state. Ground RF inhibits add physical-layer safety. Auditable containment strengthens operational control.