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Cyber analysts tend to respond to anomalous events manually, often using subjective judgment that can lead to responses that are less than optimal. Additionally, analysts tend to report on events and share cyber knowledge in unstructured, textual formats, which not only require more time to parse – thus taking more time to respond – but also lead to multiple conclusions from the same input. To remedy this, we have proposed a framework designed to provide an analyst with a set of timely and accurate courses of action in response to events, in some cases automating those responses. As part of this framework, we have created a playbook specification format that allows analysts to specify the right course of action to take in response to events, given certain risk conditions and mission context. In addition to providing the specification format, we have also created an initial ontology to help analysts build their playbook contents and have laid out a notional architecture that can operationalize these playbooks. Our playbook format can help standardize how analysts should respond to events, thus decreasing the time to response and enabling analysts to share key knowledge in a common format. Ultimately, this should increase the efficacy of security operations center personnel.

Electric propulsion may play a crucial role in the implementation of the gravity tractor planetary defense technique. Gravity tractors were devised to take advantage of the mutual gravitational force between a spacecraft flying in formation with the target celestial body to slowly alter the celestial body's trajectory. No physical contact is necessary, which bypasses issues associated with surface contact such as landing, anchoring, or spin compensation. The gravity tractor maneuver can take several forms, from the originally proposed constant thrust in-line hover to the offset halo orbit. Both can be enhanced with the collection of mass at the asteroid. The form of the gravity tractor ultimately impacts the required thrust magnitude to maintain the formation, as well as constraints on the vectoring of the thrust direction. Solar electric propulsion systems provide an efficient mechanism for tugging the spacecraft-asteroid system due to their high specific impulse. Electric propulsion systems can generate thrust continuously at high efficiency, which is an ideal property for gravity tractors that may require years of operation to achieve the desired deflection because of the very low coupling force provided by the gravitational attraction. The performance and feasibility of the deflection are predicated on having the propulsion capability to maintain the gravity tractor. This paper describes the impacts of constraining the solar electric propulsion thrust magnitude and thrust vectoring capability. It is shown that uncertainty in asteroid density and size, when combined with the enforcement of the electric propulsion constraints, can preclude the feasibility of certain gravity tractor configurations. Additionally, odd thruster configurations are shown to drive the gimbal performance and to have major impacts on eroding incident spacecraft surfaces due to plume interaction. Center of gravity movement further exacerbates issues with gimbaling and plume interaction. A tighter plume divergence angle is therefore always desired, but this paper shows that there is an optimal momentum balance between plume interaction and asteroid-plume avoidance. Several gravity tractor techniques are compared based on metrics of time efficacy, as measured by the induced asteroid delta-V per unit time, and mass efficiency, as measured by the induced asteroid delta-V per unit mass of fuel. Given the propulsion constraints, halo orbits can be infeasible for smaller asteroids unless the mass of the spacecraft is augmented with collected material through a technique called the Enhanced Gravity Tractor. Another proposed method is to alter the halo period by canting the thrusters. In-line hover gravity tractors can always be moved along the net thrust direction to conform to the given propulsion system at the expense of performance, except in the case of smaller asteroids with propulsion systems that are limited in lower throttle range or maximum gimbal angle. Alternative strategies, such as on-off pulsing the thrusters to lower the effective thrust are considered. An example is described for deflecting asteroid 2008 EV 5 (341843), which currently serves as the reference asteroid for the proposed Asteroid Redirect Robotic Mission.

Recent technology advancements in Micro Electric Propulsion (MEP) will enable the next generation of small spacecraft to perform trajectory and attitude maneuvers with significant ΔV requirements, provide thrust over long mission durations, and replace reaction wheels for attitude control. These advancements will open up the class of mission architectures achievable by small spacecraft to include formation flying, proximity operations, and precision pointing missions in both LEO and interplanetary destinations. The goal of this study is to establish the optimal performance parameters for future MEP technology that are applicable to a broad range of flight demonstration platforms (e.g. dedicated 3–12U CubeSats to ESPA-class spacecraft ), for a variety of applications, including LEO and Earth escape orbit transfers, travel to interplanetary destinations, hover and drag make-up missions, and performing reaction wheel-free attitude control. An integrated systems-level model for propulsion, spacecraft (power, data, telecommunication, thermal management), and orbit and attitude maneuvers is developed to support solution space exploration. MEP system performance parameters are derived that maximize the performance capability subject to realistic system-level constraints in the context of upcoming mission opportunities where MEP is enabling or advantageous relative to other technologies.