Ground ControlGround System’s Basic ElementsMission ElementsDeep Space Network (DSN)Control CentersData FlowPayload Operations Control CenterMission Control CenterGround System Design ProcessKey Design ConsiderationsGround ControlAERSP 401AGround System’s Basic Elements•Mission Elements–Control the space segment or handle mission data, and includes:•Ground Stations•Clocks•Operations Centers•Facility Elements–Support infrastructure that includes:•Physical plant (buildings, utilities, staff)•MaintenanceMission Elements•Ground station–Point of communication with spacecraft–Includes:•Antennas•Communication equipment•Telemetry, Tracking and Control (TT&C)•Data processing and routing•Control centersDeep Space Network (DSN)•Three sites–Goldstone (California)–Madrid (Spain)–Canberra (Australia)–The DSN includes:•3 70-meter stations, •3 26-meter stations, •9 34-meter antennas.Control Centers•SOCC–Spacecraft Operations Control Center–Monitors and commands the spacecraft bus and common systems•POCC–Payload Operations Control Center–Analyzes the telemetry and mission data from onboard payload instruments and issues commands to these instruments •MCC–Mission Control Center–Plans and operates the the entire space missionData FlowSpace Segment (S/C)Data UsersGround SystemSpacecraft and Payload SupportData RelayCommandRequestsMissionDataCommand and Tracking DataTelemetryMissionDataPayload Operations Control CenterNASA Marshall Space Flight Center, Huntsville AlabamaMission Control CenterNASA Johnson Spaceflight Center, Houston TexasGround System Design Process•Establish number and locations of ground stations•Establish space-to-ground data rates•Determine link budget and power requirements•Determine required data handling•Establish data handling location•Decide location of SOCC, POCC and MCC•Determine and select communications links•Evaluate complete or partial use of service-provided ground systems•Iterate as neededKey Design Considerations•How frequently and what duration must the spacecraft communicate with the ground?•What is the required data transmission rate?•How many data users are there?•Do we rent space on a currently existing system or do we build a dedicated