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.
A distributed system uses a number of nodes, working together, to perform the same mission or functions as a single node. In a distributed constellation, the end user is not dependent on any single satellite but rather uses multiple satellites to derive a capability. A distributed constellation can complicate an adversary’s counterspace planning by presenting a larger number of targets that must be successfully attacked to achieve the same effects as targeting just one or two satellites in a less-distributed architecture. GPS is an example of a distributed constellation because the functioning of the system is not dependent on any single satellite or ground station; a user can use any four satellites within view to get a time and position fix.*
Proliferated satellite constellations deploy a larger number of the same types of satellites to similar orbits to perform the same missions. While distribution relies on placing more satellites or payloads on orbit that work together to provide a complete capability, proliferation is simply building more systems (or maintaining more on-orbit spares) to increase the constellation size and overall capacity. Proliferation can be an expensive option if the systems being proliferated are individually expensive, although highly proliferated systems may reduce unit costs in production from the learning curve effect and economies of scale.*
In a diversified architecture, multiple systems contribute to the same mission using platforms and payloads that may be operating in different orbits or in different domains. For example, wideband communications to fixed and mobile users can be provided by the military’s WGS system, commercial SATCOM systems, airborne communication nodes, or terrestrial networks. The Chinese BeiDou system for positioning, navigation, and timing uses a diverse set of orbits, with satellites in geostationary orbit (GEO), highly inclined GEO, and medium Earth orbit (MEO). Diversification reduces the incentive for an adversary to attack any one of these systems because the impact on the overall mission will be muted since systems in other orbits or domains can be used to compensate for losses. Moreover, attacking space systems in diversified orbits may require different capabilities for each orbital regime, and the collateral damage from such attacks, such as orbital debris, could have a much broader impact politically and economically.*
A jammer or spoofer can be used to disrupt sensors on an incoming kinetic ASAT weapon so that it cannot steer itself effectively in the terminal phase of flight. When used in conjunction with maneuver, this could allow a satellite to effectively “dodge” a kinetic attack. Similar systems could also be used to deceive SDA sensors by altering the reflected radar signal to change the location, velocity, and number of satellites detected, much like digital radio frequency memory (DRFM) jammers used on many military aircraft today. A spacebased jammer can also be used to disrupt an adversary’s ability to communicate.*
*https://csis-website-prod.s3.amazonaws.com/s3fs-public/publication/210225_Harrison_Defense_Space.pdf?N2KWelzCz3hE3AaUUptSGMprDtBlBSQGate with an ASAT weapon.
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.