The terms used throughout this documentation, in alphabetical order. Each entry links to the page that explains it in full.
| Term | Meaning |
|---|---|
| ACK 1, ACK 2, ACK 3 | The three acknowledgements of a telecommand: encoded by the driver (ENCODED), sent by the gateway (SENT), verified on telemetry (VERIFIED). See Telecommand Lifecycle. |
| Alarm | A limit violation or a named condition on measures, with a lifecycle (NORMAL, ACTIVE_UNACK, ACTIVE_ACK, CLEARED_UNACK), acknowledgement, shelving and an optional automatic reaction. See Alarm Handling. |
| AOS / LOS | Acquisition and loss of signal: start and end of a pass. |
| Binding | The instances of driver, transport and gateway the reconciler assigns to a link of a target, stored in stellar_bindings. See Links and Bindings. |
| Calibration | The conversion from a raw value to a physical value, declared in the catalogue (polynomial, table, enumeration). See Measures, Limits and Calibration. |
| Catalogue | A versioned package describing a platform: components, measures, derived measures, telecommands, alarms, files and streams. See Catalogue Packages. |
| Cell | One tenant of a shared platform: a NATS account and a dedicated set of services. See Cells. |
| CFDP | The CCSDS File Delivery Protocol (727.0), one of the two transfer protocols of the files component. See File Transfers. |
| Component | A part of a platform in a catalogue (tcu, psu), possibly with several instances (tcu[TCU2]). |
| Configuration repository | The Git repository holding the desired state: catalogues, topology, libraries, simulations. See Configuration Repository. |
| COP-1 | The CCSDS retransmission protocol of telecommand frames, run by a transport and exposed through the link component. See COP-1 and the Link Component. |
| Current value | The latest sample of a measure, kept in the current value table (stellar_values). See Measures and Current Values. |
| Decision | What a run waits for when a step cannot be replayed automatically: replay, skip or abort. See Questions, Decisions and Control. |
| Deferred | Telemetry recorded on board and downloaded later (LTTM, playback), as opposed to real-time. See Time and Freshness. |
| Derived measure | A measure computed from others by an expression, pure or temporal. See Derived Measures. |
| Direct telecommand | A telecommand sent by hand (API, CLI, web console), outside a procedure. See Direct Telecommands and Values. |
| Driver | The component that translates semantic telecommands into bytes and frames into raw values, following the ICD of a target. See Writing a Driver. |
| Dry run | A run on ephemeral simulated targets, with a local NATS server started by the CLI (stellar run --dry). |
| Echo | The on-board copy of a received telecommand, compared by the driver with what it encoded (verify: [echo]). |
| Environment | A phase of the life of a target with its policies: SIM, AIT, IVV, in_orbit. See Environments and Policies. |
| Evidence | What a run records for each step: resolved inputs, acknowledgement chains, samples that decided each check, confirmations. See Evidence and Reports. |
| Feeder | A script that pushes passes to the MCS, as the flight dynamics system (fds) or the station provider (provider). See Writing a Pass Feeder. |
| Gateway | The component that carries frames to and from the medium: ground station, RF bench, CAN bus, laboratory network. See Writing a Gateway. |
| Hazardous | A telecommand that needs a confirmation before each send, by the roles the environment names. See Hazardous Confirmations. |
| Human orchestration | The block of policies of an environment about people: identity, confirmations, mandatory planning. off disables them all. |
| ICD | Interface Control Document: the binary interface of a target, implemented by its driver. |
| IR | Intermediate representation: the typed, compiled form of the configuration, encoded with postcard and addressed by its SHA-256. See Compilation, Snapshots and Locks. |
| Lease | A claim of a run on a target (stellar_leases), exclusive or shared, that keeps other runs and direct telecommands away. See Leases and Crash Recovery. |
| Library | A package of steps and procedures, with its package.yaml and stellar.lock. See Libraries and Validation. |
| Link | A way to reach a target: a driver, an optional transport and a gateway, with parameters. See Links and Bindings. |
| Lock | The stellar.lock file of a library: the hashes of the validated steps and procedures and of their dependencies. |
| LTTM | Long-term telemetry file recorded on board, downloaded and decoded into deferred samples. |
| Measure | A typed value of a component, produced by telemetry or computed (tcu[TCU1].anode_voltage). |
| Mode | A mode of operation declared by the topology (Nominal, Survival); each target has a current mode, applied by configure. See Modes and Parameters. |
| Output connector | An external process that consumes data of the MCS to store it or relay it. See Output Connectors. |
| Parameter | An on-board setting of a component (tcu.anode_voltage), whose value per target and mode the topology gives; read with param. See Modes and Parameters. |
| Pass | A window of visibility of a target over a ground station, with AOS, LOS and elevation. See Passes. |
| Platform | A model of spacecraft or equipment, described by a catalogue (platform-v3@1.4.0). |
| Procedure | A composition of steps and sub-procedures, with failure handling and allowed environments. See Steps and Procedures. |
| Readiness | Whether every link of a target is bound, with a reason per link otherwise (stellar_readiness). |
| Reconciler | The service that compares desired and observed state, binds instances and issues their credentials. |
| Role | A name a procedure gives to a target it uses, typed by platform (uses sat: platform-v3), bound at launch. |
| Run | One execution of a procedure, bound to targets in an environment, with its log. See Running Procedures. |
| Run request | The YAML or JSON document that launches a run: run, environment, targets, inputs. |
| Safe point | A moment where a target can switch to a new configuration revision: no run holding it, no pass in progress. |
| Sample | One value of a measure with its times, link and delivery. |
| Schedule | A run bound to a pass, fired by the scheduler at its start. See Scheduling. |
| Snapshot | The compiled configuration of a repository, stored in stellar_ir under its hash; the current one is named by stellar_config. |
| Step | A reusable action and its success criterion: the unit of execution, report and retry. |
| Stream | Continuous payload data carried and archived without decoding. See Continuous Streams. |
| Target | Something the MCS controls, which implements a platform: a satellite, a flatsat, a power supply, a bench. See Targets. |
| Transfer | A file transfer, download or upload, possibly spanning several passes. See File Transfers. |
| Transport | The optional component between driver and gateway that frames the units of the driver for a medium, and back. See Writing a Transport. |