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
The spacecraft shall protect mission critical subsystems from electric signal interference.
Low-Level Requirements
Requirement
Rationale/Additional Guidance/Notes
See threat ID SV-AC-1 for crypto and auth requirements. But to protect for TEMPEST. The spacecraft shall be designed such that it protects itself from information leakage due to electromagnetic signals emanations. {SV-CF-2,SV-MA-2} {PE-19,PE-19(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.
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. {SV-CF-2,SV-MA-2} {PE-19,PE-19(1)}
The Program shall describe (a) the separation between RED and BLACK cables, (b) the filtering on RED power lines, (c) the grounding criteria for the RED safety grounds, (d) and the approach for dielectric separators on any potential fortuitous conductors. {SV-CF-2,SV-MA-2} {PE-19,PE-19(1)}
Threat actors may gather information about the victim spacecraft's design that can be used for future campaigns or to help perpetuate other techniques. Information about the spacecraft can include software, firmware, encryption type, purpose, as well as various makes and models of subsystems.
Threat actors may gather information about the station-keeping control systems within the victim spacecraft that can be used for future campaigns or to help perpetuate other techniques. Information gathered can include thruster types, propulsion types, attitude sensors, and data flows associated with the relevant subsystems.
Threat actors may perform specific commands in order to modify onboard values that the victim spacecraft relies on. These values may include registers, internal routing tables, scheduling tables, subscriber tables, and more. Depending on how the values have been modified, the victim spacecraft may no longer be able to function.
Measures designed to temporarily impair the use or access to a system for a period of time. Threat actors may seek to disrupt communications from the victim spacecraft to the ground controllers or other interested parties. By disrupting communications during critical times, there is the potential impact of data being lost or critical actions not being performed. This could cause the spacecraft's purpose to be put into jeopardy depending on what communications were lost during the disruption. This behavior is different than Denial as this attack can also attempt to modify the data and messages as they are passed as a way to disrupt communications.
Measures designed to temporarily eliminate the use, access, or operation of a system for a period of time, usually without physical damage to the affected system. Threat actors may seek to deny ground controllers and other interested parties access to the victim spacecraft. This would be done exhausting system resource, degrading subsystems, or blocking communications entirely. This behavior is different from Disruption as this seeks to deny communications entirely, rather than stop them for a length of time.
Measures designed to permanently impair (either partially or totally) the use of a system. Threat actors may target various subsystems or the hosted payload in such a way to rapidly increase it's degradation. This could potentially shorten the lifespan of the victim spacecraft.
This technique is a result of utilizing TTPs to create an impact and the applicable countermeasures are associated with the TTPs leveraged to achieve the impact
Organizations should look to identify and properly classify mission sensitive design/operations information (e.g., fault management approach) and apply access control accordingly. Any location (ground system, contractor networks, etc.) storing design information needs to ensure design info is protected from exposure, exfiltration, etc. Space system sensitive information may be classified as Controlled Unclassified Information (CUI) or Company Proprietary. Space system sensitive information can typically include a wide range of candidate material: the functional and performance specifications, any ICDs (like radio frequency, ground-to-space, etc.), command and telemetry 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, CUI, proprietary, 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. Sensitive documentation should only be accessed by personnel with defined roles and a need to know. Well established access controls (roles, encryption at rest and transit, etc.) and data loss prevention (DLP) technology are key countermeasures. The DLP should be configured for the specific data types in question.
The credibility and effectiveness of many other types of defenses are enabled or enhanced by the ability to quickly detect, characterize, and attribute attacks against space systems. Space domain awareness (SDA) includes identifying and tracking space objects, predicting where objects will be in the future, monitoring the space environment and space weather, and characterizing the capabilities of space objects and how they are being used. Exquisite SDA—information that is more timely, precise, and comprehensive than what is publicly available—can help distinguish between accidental and intentional actions in space. SDA systems include terrestrial-based optical, infrared, and radar systems as well as space-based sensors, such as the U.S. military’s Geosynchronous Space Situational Awareness Program (GSSAP) inspector satellites. Many nations have SDA systems with various levels of capability, and an increasing number of private companies (and amateur space trackers) are developing their own space surveillance systems, making the space environment more transparent to all users.*
*https://csis-website-prod.s3.amazonaws.com/s3fs-public/publication/210225_Harrison_Defense_Space.pdf?N2KWelzCz3hE3AaUUptSGMprDtBlBSQG
The spacecraft should protect system components, associated data communications, and communication buses in accordance with TEMPEST controls to prevent side channel / proximity attacks. Encompass the spacecraft critical components with a casing/shielding so as to prevent access to the individual critical components.
When AI/ML is being used for mission critical operations, the integrity of the training data set is imperative. Data poisoning against the training data set can have detrimental effects on the functionality of the AI/ML. Fixing poisoned models is very difficult so model developers need to focus on countermeasures that could either block attack attempts or detect malicious inputs before the training cycle occurs. Regression testing over time, validity checking on data sets, manual analysis, as well as using statistical analysis to find potential injects can help detect anomalies.
Employ the principle of least privilege, allowing only authorized processes which are necessary to accomplish assigned tasks in accordance with system functions. Ideally maintain a separate execution domain for each executing process.
This countermeasure is focused on the protection of terrestrial assets like ground networks and development environments/contractor networks, etc. Traditional detection technologies and capabilities would be applicable here. Utilizing resources from NIST CSF to properly secure these environments using identify, protect, detect, recover, and respond is likely warranted. Additionally, NISTIR 8401 may provide resources as well since it was developed to focus on ground-based security for space systems (https://nvlpubs.nist.gov/nistpubs/ir/2022/NIST.IR.8401.ipd.pdf). Furthermore, the MITRE ATT&CK framework provides IT focused TTPs and their mitigations https://attack.mitre.org/mitigations/enterprise/. Several recommended NIST 800-53 Rev5 controls are provided for reference when designing ground systems/networks.
Implement disaster recovery plans that contain procedures for taking regular data backups that can be used to restore critical data. Ensure backups are stored off system and is protected from common methods adversaries may use to gain access and destroy the backups to prevent recovery.
Utilize on-board intrusion detection/prevention system that monitors the mission critical components or systems and audit/logs actions. The IDS/IPS should have the capability to respond to threats (initial access, execution, persistence, evasion, exfiltration, etc.) and it should address signature-based attacks along with dynamic never-before seen attacks using machine learning/adaptive technologies. The IDS/IPS must integrate with traditional fault management to provide a wholistic approach to faults on-board the spacecraft. Spacecraft should select and execute safe countermeasures against cyber-attacks. 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 — with or without ground support. 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.
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.
Provide the capability to enter the spacecraft into a configuration-controlled and integrity-protected state representing a known, operational cyber-safe state (e.g., cyber-safe mode). Spacecraft should enter a cyber-safe mode when conditions that threaten the platform are detected. 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 software functions to pre-attack 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 equipment still available after a cyber-attack. The goal is for the spacecraft to resume full mission operations. If not possible, a reduced level of mission capability should be achieved. Cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.
Identify the key system components or capabilities that require isolation through physical or logical means. Information should not be allowed to flow between partitioned applications unless explicitly permitted by security policy. Isolate mission critical functionality from non-mission critical functionality by means of an isolation boundary (implemented via partitions) that controls access to and protects the integrity of, the hardware, software, and firmware that provides that functionality. Enforce approved authorizations for controlling the flow of information within the spacecraft and between interconnected systems based on the defined security policy that information does not leave the spacecraft boundary unless it is encrypted. Implement boundary protections to separate bus, communications, and payload components supporting their respective functions.
If available, use an authentication mechanism that allows GNSS receivers to verify the authenticity of the GNSS information and of the entity transmitting it, to ensure that it comes from a trusted source. Have fault-tolerant authoritative time sourcing for the spacecraft's clock. The spacecraft should synchronize the internal system clocks for each processor to the authoritative time source when the time difference is greater than the FSW-defined interval. If Spacewire is utilized, then the spacecraft should adhere to mission-defined time synchronization standard/protocol to synchronize time across a Spacewire network with an accuracy around 1 microsecond.