The Space Wire protocol is a intra-satellite communication protocol. It allows different components of spacecraft to communicate with each other.

An ASIC is a custom chip, designed for a specific purpose.

An error detection and correction (EDAC) code, or error correcting code (ECC), is a mechanism to detect and correct memory errors.

An FPGA is chip where instead of re-programming the firmware, the actual layout of the gates can be re-programmed. This makes it possible to implement logic that runs significantly faster than what can be achieved on a micro-controller.

A Latching Current Limiter is a resettable fuse, an electronic component that detects over-current events, and interrupts the flow of current, preventing damage to downstream components.

Magnetoresistive Random-Access Memory (MRAM) is a type of Non-Volatile Memory where data is stored as a magnetic field. It offers the speed of SRAM, a density similar to DRAM, the non-volatility of Flash Memory and unlimited read/write cycles, and low power consumption.

Static RAM (SRAM) is a type of volatile Random Access Memory. Volatile memory needs to be regularly refreshed otherwise its contents is erased.

Synchronous Dynamic Random-Access Memory is a type of Volatile Memory. It is the ancestor of the common DDR, or Double Data-Rate memory technologies found in RAM sticks in modern computers.

A twisted pair, as indicated by the name, is composed of two wires, twisted together. They are often used in communication protocols because they reduce the amount of electro-magnetic noise emitted by the cable.

Volatile memory is memory that forgets the information stored in it when it is powered down (e.g. SDRAM). Non-volatile memory is memory that retains information when powered down (e.g. a hard-drive, or a solid-state drive).

In manned spaceflight missions, the Capsule Communicator (CAPCOM) is the person in the Mission Control Centre (MCC) that talks, or authorises others, to talk to the astronauts.

The Mission Control Centre (MCC) is the location from which a satellite is controlled.

A sun-synchronous orbit is an orbit in which the spacecraft passes over any given point on the planet's surface at the same local solar time.

A cryptographically relevant quantum computer is a notional quantum computer that would be able to break classical encryption keys in a reasonable amount of time.

Quantum Key Distribution (QKD) is the process of distributing secret keys, usually used for encryption and authentication, in such a way that any attempt to eavsdrop on the exchange is immediately detected.

A multiple-bit upset is a single-event upset that affects multiple memory bits.

A single-event transient is is a radiation-induced failure, where a high-energy particle causes an electrical pulse inside a device. Unlike a single-event latchup, it is temporary, and causes no damage to the device.

A single-event latchup is a radiation-induced failure in which a transistor allows excessive current to flow, potentially damaging connected components.

A Single-Event Upset (SEU) or Single-Bit Upset (SBU), is a radiation-induced failure, where one or more values stored in memory are corrupted.

A parity bit, or check bit, is added to a data stream as an Error Detection and Correction Code.

RTEMS is a Real-Time Operating System commonly used in ESA missions. It is the only Space Qualified operating system approved by ESA.

A real-time operating system ensures that tasks executed at consistent times, with minimal jitter.

The European Space Agency (ESA) is Europe's civilian space agency. It is sometimes disparagingly referred to as the _other NASA.

The National Aeronautics and Space Administration is the Space Agency of the United States of America.

The Command Pulse Distribution Unit (CPDU) is a simple equipment designed to provide direct access to equipment on a spacecraft from ground.

A Heater Latching Current Limiter (HLCL), is a type of Latching Current Limiter (LCL) protecting one-or-more heaters.

A Hold-Down and Release Mechanism (HDRM) is an equipment on a spacecraft used to hold a part in a fixed position, and release when commanded.

The On-Board Computer (OBC) of an instrument or payload.

The On-Board Computer is the heart of the space craft, it is the main computer, it commands the operation of the sensors, actuators, and payloads of the spacecraft.

Component of space craft that manages power distribution throughout the spacecraft.

A Retriggerable Latching Current Limiter (RLCL), is a Latching Current Limiter (LCL) that automatically re-enables when the current overload is removed.

The Space AVionics Open Interface aRchitecture (SAVOIR) is an initiative to federate the space avionics community and to work together in order to improve the way that the European Space community builds avionics sub-systems.

The Spacecraft Onboard Interface Services (SOIS) standard is a CCSDS document, that aims to standardise the interfaces between items of a spacecraft.

Triple-modular redundancy is a form of spatial redundancy in which logic is replicated three times, and their outputs are compared in a comparator.

Telecommands (TC) are the commands sent to a system or spacecraft.

Telemetry (TM) is information about the state of a system or spacecraft.

Telemetry, Tracking, and Command (TT&C) data refers to the Telemetry (TM) downloaded from a spacecraft, and the Telecommand (TC) uploaded to it.

The Consultative Committee for Space Data Systems (CCSDS) is a multi-national forum for the development of communications & data systems standards for spaceflight.

The European Cooperation for Space Standardization is an initiative established to develop a coherent, single set of user-friendly standards for use in all European space activities.

The gray (Gy) is the SI unit for the Total Ionizing Dose (TiD), defined as the absorption of one Joule of radiation energy per kilogram of matter. The corresponding unit in the CGS system is the Rad.

The Rad is a measure of the Total Ionising Dose (TiD) in the CGS system. In SI units, it has been replaced by the Gray (Gy), and its use is strongly discouraged, but it is still common in the US.