telecommand
Telecommand is the transmission of commands to a remote system to perform actions. In spaceflight, telecommand (TC) refers to instructions from ground stations or mission control to a spacecraft or its subsystems, enabling operations such as attitude adjustments, mode changes, instrument activation, or safe-mode entry. Telemetry (TM) is the reverse data flow, from spacecraft to ground.
Telecommands are digital and typically packetized data sent over radio or optical links. The spacecraft decodes,
Standards and encoding: Telecommand structure is defined in space data system standards, notably the CCSDS Telecommand
Security and reliability: Command transmission includes error detection, often with CRCs or parity checks, and may
Applications and scope: Telecommands are essential for spacecraft operations, payload control, and testing. The ground segment