# High-Tech Defense Industries: Developing Autonomous Intelligent Systems
## 2 Conceptual Background
### Military Applications of Autonomous Intelligent Systems  
The defense industry is increasingly conducting autonomous defense systems research and development in several domains: space, cyberspace, air, sea, and land. It is in that regard that we present an overview of military application of autonomous defense systems in each of the aforementioned domains:  
* Space robotics and autonomous intelligent systems;
* Autonomous intelligent cyber-defense agents;
* Intelligent unmanned autonomous systems--in the air, at sea, and on land. Space robotics autonomous intelligent systems are presented as machines capable of operating in space and carrying out exploration in adverse environments that may not be found in the natural conditions of earth. In general, space robots are divided into two types: (1) orbital robots [40], which are characterized by robotics in low earth orbit or robotics in geostationary orbit; and (2) planetary robots [41], which are capable of closely examining extraterrestrial surfaces. As mentioned by [PERSON] et al. [42], depending on the applications (orbital or planetary), space robots are often designed to be mobile, manipulate, grab, drill and/or collect samples, such as the National Aeronautics and Space Administration's recent Mars 2021 Perseverance Rover [43]. These robots are expected to have several levels of autonomy, from tele-operation by humans to fully autonomous operations. Depending on the level of autonomy, a space robot can act as [42]: (1) a robotic agent (or human proxy) that can perform tele-operation up to semi-autonomous operations; (2) a robotic assistant, who can help human astronauts that range from semi- to fully-autonomous operations; or (3) a robotic explorer capable of exploring unknown territory in space using fully autonomous operations. As an exemplary method, [PERSON] et al. [40] is presented as a validating benchmark. They reported an efficient fuel control strategy for a spacecraft equipped with a manipulator. Their key findings are associated with the strategy of using the thrusters, the reaction wheels, and the arm drives in a coordinated way to limit the use of the thrusters and achieve the ideal zero fuel consumption in non-contact maneuvers. The authors were able to validate the method via a hardware-in-the-loop simulator composed of a seven degrees of freedom arm mounted on a simulated six degrees of freedom spacecraft. Some military space robotics autonomous intelligent systems are related to spy satellites of some military powers and space-based missile defense systems. Autonomous cyber defense is an area that has been driven by the defense sector in anticipation of threats to military infrastructures, systems, and operations [44]. These systems will be implemented through autonomous and intelligent cyber-defense agents that will fight against intelligent autonomous malware [44] and are likely to become primary cyber fighters on the future battlefield [45]. The popularity of advanced applications in the domains of air, land, and sea has also been steadily increasing [46] with the intelligent unmanned autonomous systems, which can perform operations without human intervention with the help of artificial intelligence [8]. In that regard, intelligent unmanned aircraft systems have aimed at autonomous flight, navigation, sensory, and decision-making capabilities [47] above conventional unmanned aircraft systems or unmanned aerial vehicles. Currently, unmanned aircraft systems and unmanned aerial vehicles systems have often been used for intelligence, surveillance, and reconnaissance activities or to carry out attack missions against high-value targets [48]. In addition, several methodologies have been targeted to these systems, such as [PERSON] et al. [49], who designed an approach to mitigate common unmanned aerial vehicle failures, including primary control surface damage, airframe damage, and complete engine failure.