Some of the definitions included herein are based on the ECSS-S-ST-00-01C.
- AIV [acr.]: Assembly, Integration, and Verification
- Applicable document [noun]: document that contains provisions which, through reference in the source document, constitute additional provisions of the source document. It can also be reffered to as a "necessary" document.
- CDF [acr.]: Concurrent Design Facility.
- CDHS [acr.]: Command and Data Handling System.
- CE [acr.]: Concurrent Engineering.
- CE Software [noun]: Program made to share data during a CE session. Examples: COMET (with Excel extension), ValiSpace, etc.
- CoG [acr.]: Center of Gravity, also called center of mass, fictive coordinate where the resulting gravitational force applies
- Concurrent [adj.]: Design done in parallel, at the same time, and with conflicting requirements for all subsystems that force trade-offs and compromises.
- ConOps [acr., noun]: Concept of Operations. High-level, visual description of the phases of the mission.
- COTS [acr., adj.]: Commercial Off the Shelf (opposite of "developed in house" or SRAD)
- CP [acr.]: Chemical Propulsion
- Customer [noun]: Person, or company asking for the session to take place. They bring the needs and high level requirements and can accompagny the experts and SEs during the session to answer questions, validate chocies, refine requirements, etc.
- Domain of Expertise [on COMET]: subsystem on which a Participant is working during the session. Domains of expertise in the CE tool shall match the subystems represented in the CDF layout.
- ECLSS [acr.]: Environmental Control and Life Support System.
- Element [noun]: combination of integrated equipment, components and parts of a subsystem. An element fulfils a major, self-contained, subset of a segment's objectives. Each element is defined by parameters.
- Element Definition [on COMET]: the building blocks of an COMET model, characterised by parameters. Can represent mission - (element, equipment, function, subsystem, manoeuvre, etc...). All Element Definitions are made on the same level.
- Element Usage [on COMET]: created to use an Element Definition B as part of another Element Definition A. Elements Usages inherit any modifications done to the Element Definition and Parameters on the Element Definition level, and change automatically.
- EP [acr.]: Electrical Propulsion
- Expert [noun]: Participant to the CE session. Usually assigned to one subsystem.
- Facilitator [noun]: Systems engineer that conduct the CE session, make sure every experts follow the synchronization process, that data is up-to-date, exchanged, and that the team's morale creates an efficient and pleasant working atmosphere.
- Finite States [noun]: List of states in which the system, or the subsystems, can be. E.g: mission phases, system modes, etc. Finite states can be combined to create sub classes of states, some of which can be forbidden (impossible).
- GS [acr.]: Ground Station.
- GTO [acr.]: Geostationary Transfer Orbit.
- ISL [acr.]: Inter satellite link
- Isp [acr., parameter]: Specific Impulse [s]
- LCROSS [acr.] Lunar CRater Observation and Sensing Satellite
- LLO [acr.] Low Lunar Orbit
- LOI [acr.] Lunar Orbit Insertion
- LRO [acr.] Lunar Reconnaissance Orbiter
- MLI [acr.]: Multi Layer Insulation
- Model [noun]: The model of a system includes all information used to define it. All the subsystems, elements, parameters, states rules, etc. [on COMET] Specifically, a COMET model comprises the information of all disciplines / domains of expertise pertinent to the space mission in study.
- Modes [noun]: System modes. State in which an equipment, subsystem, or system, can be. E.g: Launch mode, Nominal, Safe, Standby, Active, Passivated, On, Off, etc.
- MoI [acr.] Moment of Inertia [kg*m2]
- OBC [acr.]: On-Board Computer
- OBDH [acr.]: On-Board Data Handling
- Ownership [on COMET]: the Domain of Expertise that has created an Element Definition or a new parameter has ownership over it. The [persons] assigned to this domain are responsible for their existance and to keep them up to date.
- Parameter [noun]: Physical properties of an element that allow to describe it. Each parameter has a unit. E.g: mass [kg], volume [m3], power [W]. New parameters can be defined in the CE software. Domain of Expertise can subscribe to parameters.
- Parameter types [on COMET], predefined parameters in the RDL (eg. mass, volume, power, ...) with an assiciated unit (and scale).
- Participant [on COMET]: (Role on COMET): working on an engineering model, a participant can usually either be a "Domain Expert", or a "Design Authority". Both may read anything, but the former can modify / delete only things owned by his/her Domain of Expertise, while the latter can modify / delete anything and perform publications. New participant role can be create in COMET>Directory>Roles (customer, observer, author, ...).
- PCDU [acr.]: Power Conditioning and Distribution Unit
- Person [on COMET]: (Role on COMET): when accessing a COMET site, a person can usually either be a "Site Administrator", or a "Concurrent Design Team Member". The former has access to everything (should be the systems engineer(s) and study facilitator(s)). The latter can modify their own Person account, list and open Engineering Models in which he/she is a Participant. New person role can be create in COMET>Directory>Roles.
- Phase [noun]: Mission phase, a list of possible phases a mission can be in along the whole duration of the mission, eg. from launch and early operations, commissionning, insertion, deployment, operations, science, transit, end-of-life, etc.
- Publication [noun]: The outcome of the "publish" step. Stored in COMET.
- Publish (onto) [verb]: A task for the systems engineers. Once experts have pushed their newest values, SEs will verify them, make sure they are reasonable (in the expected order of magnitude). SEs can use the values to create budgets estimate and compile them to push the values of the parameters they own. Finally once verified, SEs will publish the values which will in fact share them onto the CE software and allow all experts to satrt a new iteration by pulling the new values.
- Pull (from) [verb]: To synchronize from the CE software, to one local, working copy. After pulling, experts can design their subsystems but their newest values are not synchronized with the others.
- Push (to) [verb]: Once experts get at the end of one design iteration, they can push their newest values to the CE software. Values are not yet shared with other experts, not until they are published by the SEs.
- RDL [acr.], reference data library (on COMET)
- Redundancy [noun]: Scheme can be hot (all units always on – fast switch-over) or cold (k units on, n-k off, meaning less wear / less power consumption). Type can be internal (redundant units all in single package / box) or external (redundant units explicitly modelled in design).
- Reference Data [on COMET]: consists of predefined generic data that can be used across many studies / projects. For instance parameter types (length, mass, power, energy, launch date, …), measurement units, measurement scales, categories (Functions, Products, Equipment, Components, …).
- Reference Data Library (RDL) [on COMET]: Each Engineering Model has one Model RDL to define reference data local to the model, and links one or more Site RDLs for generic reference data.
- Reference document [noun]: a document that provides pertinent details for consultation about a subject.
- Roles [on COMET]: Roles are assigned to participants to give them permissions on the model. Two types of roles exist: Person - (about the site) and Participant - (about the engineering model).
- SE [acr.]: Systems Engineer(ing).
- Session [noun]: A design session is attended by experts, SEs, facilitators, and customers, to design a product/mission/service using concurrent engineering. Sessions have a defined duration, several sessions are usually required to perform a study.
- SF [acr.]: Safety Factor (Acceptable value over max value). Not the same as a Margin of Safety.
- Site [on COMET]: Synonym for server.
- SRAD [acr., adj.]: Student Researched and Developed (opposite of COTS)
- Study [noun]: Whole concurrent engineering process for one project, with its own objectives. A study lasts several sessions, usually spread on several days.
- Subscribe (to) [verb]: For parameters that have an impact on one's subsystem's design, ask the CE software to pull the updated value of the parameter at each synchronization. The subscription process shall be done at the beginning of the session, but experts can subscribe to a parameter at anytime. The value will be updated only after a full round of synchronization: push, publish, pull.
- Subsystem [noun]: Part of the system being designed by concurrent engineering. Each subsystem has one or more expert(s) assigned to them to design them. Subsystems are made of elements (equipment level).
- TRL [acr.]: Technology Readiness Level.
- Workstation [noun]: Place equipped with a computer, useful software, and communication means, that allow an expert to work during a CE session.