Artificial Intelligence (AI) is a branch of computer science that focuses on creating systems capable of performing tasks that typically require human intelligence. The main capabilities of an AI system are perception, reasoning, learning and decision-making. It has demonstrated its ability to carry out very complex tasks with great proficiency. 

AI can be used in extremely diverse application in all the domains of space system developments covering the full engineering process, operations and exploitation as well as legal and management aspects. The aim of the process is to harmonise the development of these AI techniques in view of their application to the different domains of space systems. 

The coverage of this topic is classified as below:

• Perception: the ability to transform raw sensorial inputs (e.g., images, sounds, etc.) into usable information.
• Knowledge: the ability to represent and understand the world.
• Learning: the ability to learn patterns, trends, and features from data and make associated inferences.
• Reasoning: the capability to solve problems.
• Planning: the capability of setting and achieving goals.
• Communication: the ability to understand language and communicate.

The topic is not expected to cover the development of new AI applications, which are instead the focus of the domain-specific harmonisation topics, neither is it intended to perform fundamental research into AI. Rather it will focus on harmonisation of the AI technology, paradigms and techniques common across the development, operations and exploitation of space systems in various application domains. 

Actuators in space are broadly used to operate satellite platform and payload devices. Despite their common use, actuators still represent a critical component as their failure might often lead to severe, or even catastrophic, effects on spacecraft operations. This topic covers motors, transmission stages and position sensors, but not guiding system technologies (e.g. bearing), drive electronics, or force and torque sensors. The appeal of Harmonisation lies in establishing generic component building blocks that reduce the time and cost of developing actuation systems for specific missions.

- Actuators based on electric motors

• Electric motors: brushed motors, brushless motors, stepper motors
• Transmission stages
• Position and speed sensors: switches, low accuracy position sensors, high accuracy position sensors, speed sensors

- Piezo-actuators

• Smart material actuators
• Shape memory alloy actuators
• Other smart material actuators

- Limited stroke actuators

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Additive Manufacturing (AM) is widely regarded as a revolutionary technology that promises to transform design and production in many industries, including. This topic covers manufacturing technologies by additive processing of materials, as well as hybrid manufacturing by combining additively made appendices onto conventionally made parts or by mixing two additive manufacturing processes to make a single part. Hybrid manufacturing also includes aspects such as machining of interfaces, surface finishing, assembling and joining (e.g. welding of Al alloys) and thermal treatments. The topic addresses the areas listed below.

- Design tools, guidelines and rules based on geometrical capabilities of AM.

- Development of materials for AM:

• New/specific materials best suited to AM (e.g. low CTE alloys, new ceramics, high strength aluminium alloys, MMC, hybrid polymers compatible with C fibres).
• Adaptation of conventional materials to make them compatible with AM.

- Material procurement, characterisation and recycling.

- PA and QA requirements and verification tools required to reach the quality level for space use.

- Out-of-Earth AM technologies.

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The guidance, navigation, and control (GNC) or attitude and orbit control subsystem (AOCS) of a space vehicle relies on estimating the state of the spacecraft from measurements made by sensors, deriving the required control actions by comparing with the guidance profile to change the current state of the spacecraft into the desired state via control actions using actuators. This topic covers the hardware elements of the GNC/AOCS system.

• Active Pixel Sensor (APS) detectors for AOCS
• Star trackers
• Inertial Measurement Units (IMU), gyroscopes and accelerometers
• Magnetometers
• Magnetic Torquers
• Sun sensors
• Earth sensors
• Hybrid navigation sensors
• 3D cameras, altimeters and LIDARs for AOCS
• Optical navigation sensors
• Reaction wheels
• Control moment gyroscopes

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An array antenna is a system obtained by connecting a group of small radiating sources and organising them in such a way that their received or transmitted signals are in the correct and desired electrical relationship (in terms of phase and amplitude). While reflector antennas with a single feed usually scan the beam mechanically by moving the reflector, a phased array can scan the beam electronically by changing the relative excitation of its elements. This topic covers space-borne and ground-based Array Antennas including transmit and receive array antennas categorised as listed below.

- Passive arrays:

• Direct Radiating Arrays in transmission or reception
• Reflectarrays & Transmitarrays
• Lenses

- Active arrays:

• Direct Radiating Arrays in transmission or reception
• Reflectarrays & Transmitarrays
• Lenses

- Hybrid arrays:

• Arrays with hybrid Electronic and Mechanical scanning
• Arrays with hybrid RF & Digital and/or Photonic beamforming
• Semi-Active Direct Radiating Arrays in Tx or Rx
• Arrays organized in Overlapped Subarrays

In terms of applications, the topic addresses broadband and broadcast active/flexible antennas for GEO (L to Ku/Ka/ Q/V), government satcom active antennas including anti-jamming and source location, constellations mainly active antennas including mobile and radar DRA’s (L to Ka), intersatellite link high-speed data transmission antennas, Very High Throughput Satellites (VHTS) and digital HTS/VHTS, mobile and Science missions (array fed reflector up to 12m), passive multi beam antennas for GEO (L to Q/V) including feeder link/gateway antenna, mobile communication (mainly L/S- band, broadcast), navigation, Synthetic Aperture Radar (high performance SAR EO systems in L-, C- and X-Band), passive radiometers and interferometers (multiband L to Ka and up to mm wave) and Earth Observation/Science high-speed data transmission antennas.

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This topic covers the technologies needed for the implementation of space robotics missions. It is structured in the areas listed below.

- Space robotics applications

• Orbital robotics: Active debris removal and in-orbit servicing, manufacturing, and assembly
• Planetary robotics (handling/assembly of surface infrastructure elements, novel aerobot concepts, novel robot concepts for exploration, micro and nano rover concepts and swarms, interaction/support with in-situ resource utilisation for manufacturing)

- Automation and robotics systems

• Manipulation systems: large (>3m) and medium to small (<3m) robot arms, end-effectors, tools, tool exchangers, and system interconnects for orbital use
• Mobility systems: underground, surface, and aerial mobility, and payload automation
• Automation and robotics components
• Sensing and perception processing
• Control, autonomy and intelligence
• Motion and actuation
• Human-Robot interaction
• Robot ground testing

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Avionics Embedded Systems control all on-board functions that manage a spacecraft and its communications, payload and mission. This topic includes the areas listed below.

- Architectures and interfaces: avionics architecture covers software, hardware and communications architectures

- Avionics system functions

• On-board communication
• On-board autonomy
• Fault detection, isolation and recovery
• Distributed systems (for systems formed by 2 or more satellites)
• Operability

- Development process and related methods and tools

• Model based avionics engineering (see also Model Based for System Engineering)
• Advanced control techniques
• Evolvable/reconfigurable avionics systems
• Multicore processors
• Verification and validation

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This topic focuses on the whole data lifecycle, from data acquisition (e.g. by space-borne, low or high altitude sensors, ground-based sensors) retrieved directly or via satellite and ground relay, to successive data management, analysis and exploitation in various domains and applications such as Earth Observation, Space Science, Satellite Telecommunications, Satellite Navigation, and Space Safety. The topic covers four main layers of the space data lifecycle.

• Data Acquisition: collection and acquisition of different types of data, sources, actors and methods.
• Data Organisation: formats, structure and storage methods.
• Data Analysis: processing and transformation (algorithms, libraries, toolboxes) including visualisation methods and tools.
• Information Provision: services based on the extracted information and value-added processing for decision making.

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Chemical Propulsion includes different types of propulsion systems and components for space systems, from simple cold gas systems to monopropellant and bipropellant systems with increasing complexity. The corresponding thrust levels range from a several milli-Newton up to several kilo-Newton, as required for exploration activities. This topic covers the areas listed below.

- Chemical thrusters

• Cold Gas
• Mono-propellant (catalytic decomposition)
• Bi-propellant (Unified and Dual-mode), including green propellant compounds 
• High thrust hydrocarbon engines (e.g. LOX/kerosene, LOX/ethanol)
• Solid propellant motors
• Hybrid thrusters (solid and liquid propellants in bipropellant combination)

- Thin walled tanks

• Propellant and pressurant tanks
• Electric propulsion Xenon tanks
• Smart tanks (with integrated sensors)

- Pressure regulators and sensors

- Filters

- Valves: service valves, isolation valves (pyrotechnic valves, and shape memory alloy valves), latching valves, check valves

- Electric pumps

- Micro-launcher, in-space transportation and return from space engines (for de-orbiting and landing)

For chemical propulsion technologies intended for CubeSat applications (equal or below 0.5N per thruster) please see CubeSat Propulsion.

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This topic addresses the design, modelling, manufacturing, and characterisation of coatings for use in space. A classification of the covered technologies is done in three categories, based on the objective of the coating.

• Coatings for ground and space environment protection: includes, among others, coatings for corrosion, radiation, or atomic oxygen protection.
• Coatings for operational environment protection: includes coatings to protect materials from the constraints imposed by the application. E.g. environmental barrier coatings for high temperature applications (e.g. propulsion, re-entry) and conformal coatings for electronic components.
• Functional coatings: to impart a specific function to material on which they are deposited. This category includes, among others, coatings for antennas and RF components, optical components, and variable emissivity coatings for thermal control.

Transversal aspects to the three coating categories such as design, modelling, manufacture, characterisation and verification are also covered.

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