Spacecraft Operations Course

, DLR Spacecraft Operations Course Course Content The following subjects and topics will be addressed during the Spacecraft Operations Course

Table of Content Spacecraft Operations Course, DLR TABLE OF CONTENT... 2 INTRODUCTION AND OVERVIEW... 2 BACKGROUND... 3 SPACE ENVIRONMENT... 3 SATELLITE DESIGN... 3 FLIGHT DYNAMICS... 3 ORBIT ASPECTS... 3 MISSION ANALYSIS... 4 ATTITUDE DYNAMICS... 5 FLIGHT DYNAMICS ON-CONSOLE TRAINING... 5 MISSION PLANNING... 5 CONCEPTS AND METHODS... 5 MISSION PLANNING ON-CONSOLE TRAINING... 5 SATELLITE OPERATIONS... 6 PROJECT MANAGEMENT... 6 MISSION OPERATIONS... 6 TELEMETRY, COMMAND, RANGING SUBSYSTEM (TCR) ONBOARD SUBSYSTEM... 7 DATA HANDLING (DH) SUBSYSTEM... 7 AOCS SUBSYSTEM OPERATIONS... 7 PROPULSION SUBSYSTEM OPERATIONS... 8 PWR SUBSYSTEM OPERATIONS... 8 THM SUBSYSTEM OPERATIONS... 9 REPEATER SUBSYSTEM OPERATIONS... 9 SCIENTIFIC INSTRUMENTS OPERATIONS... 10 ON CONSOLE TRAINING... 11 GROUND SEGMENT... 12 GROUND STATION NETWORKS... 12 GROUND STATION DESIGN... 12 CONTROL CENTRE FUNCTIONS... 13 Introduction and Overview Organisation of the Course o Welcome o Time plan o Transportation o Structure of Lectures

, DLR Overview of DLR o General Overview o Site Oberpfaffenhofen/Weilheim GSOC Tasks o Experience o Ongoing and Future Missions Background Space Environment The range of environment encountered o Pre-launch o Launch vehicle o Operational The effects on spacecraft design o Vacuum o Electromagnetic Radiation o Particle radiation o Zero gravity o Atmospheric drag o Debris o Atomic oxygen o Solar wind o Radiation pressure Satellite Design The definition of space system engineering Mission Requirements Mission Objectives Specific System Design Tools o Design Drivers o Trade-offs Concurrent Engineering Examples of satellite system design for a range of spacecraft missions Alternative approaches to spacecraft system design Flight Dynamics Orbit Aspects Introduction Orbit Determination o Concept of orbit determination o Tracking data types

, DLR Angle measurements Range measurements Doppler measurements GPS measurements o Achieved accuracy Support of Operations o Ground System Network Support Scheduling support Antenna pointing predictions o Mission Operations Support Event prediction, support of SOE generation Loading of on-board orbit propagator Manoeuvre Planning o Orbit maintenance of a LEO Node, eccentricity and inclination control Separation control o Geostationary injection manoeuvres o Geostationary station keeping Mission Analysis Introduction Orbital Mechanics o Orbital Elements o Co-ordinate Systems Types of Missions o Earth observation missions o Scientific missions o Geostationary missions o Constellations Mission Analysis Examples o Earth Observation Mission First acquisition Ground track Repeatability Station visibility Coverage Shadows Lifetime o Geostationary Mission Scenario Transfer orbit Ground station network First acquisition Injection strategies Constraints Launch window Fine station acquisition

Attitude Dynamics Spacecraft Operations Course, DLR Definition of attitude Coordinate systems Parametrisation o Direction cosine matrix o Euler angles o Quaternions Attitude determination o a simple algorithm and its application Attitude control o the loop and how to work with it Flight Dynamics On-Console Training Launch and Early Orbit Phase of a Low Earth Orbiting satellite o Mission preparation (Ground station scheduling with nominal injection elements) o Sequence of orbit determinations (over 4 orbits) o Replanning of ground station schedule o Display of CHAMP orbit with the LEO software Station Acquisition of a geostationary satellite: o Planning of station acquisition maneuvers A demonstration with examples and a training how to use flight dynamic tools will be included in this session. Mission Planning Concepts and Methods Overview Fundamentals Meta Language & Problem Modelling Increment planning o long-term o short-term o re-planning Envelope Method Optimisation Methods Mission Planning On-Console Training GSOC's generic Mission Planning System: ATLAS PINTA

PLATO TIMON Spacecraft Operations Course, DLR A demonstration with examples and a training how to use the mission planning tools will be included in this session. Satellite Operations Project Management Tasks and Tools from Project Preparation through Execution o tasks of the Project Management necessary for acquisition, preparation and execution of a commercial project (reference project: EUTELSAT W Series) o tools and facilities necessary for successful completion of this type of mission Management Tasks and Tools during: o Acquisition Phase Marketing and Creation of the Proposal Contract Negotiations and Signature o Preparation Phase From Kick-Off to Operational Readiness Review (ORR) In-house activities and management of the project Management of subcontracts and execution of options; conflict management Customer Interface Management (formal reviews) From ORR to Lift-Off Administrative activities required for LEOP preparation and execution Technical management to secure the Launch Readiness and LEOP performance o Mission Execution Phase the Project Manager will act as the Mission Operations Director Management of the LEOP (on console position) Management of the Stand By Phase Mission Operations Mission Preparation Phase o Definition, generation and implementation of operational tools Operational documentation (Hard- and Software) o Test and training Test and validation of all tools End-to-end tests Cross-training Simulations Rehearsals Mission Execution Phase o General tasks, Staffing Profile o LEOP operations

, DLR o IOT Operations o Routine Operations (different orbits - different mission scenarios) LEO (e.g. CHAMP) High eccentric (e.g. EQUATOR-S) Geostationary Deep Space Post Mission Phase o Data Archiving and Analysis o Mission Reports o Lessons Learned o Stand-By Telemetry, Command, Ranging Subsystem (TCR) Onboard Subsystem Subsystem overview o Specific Functions (geostationary and scientific Satellites) o Automated operations functions (U/L, D/L) o Operation performed via ground control o Modifications (coding, coherent, ranging etc.) Initial Acquisition and Commissioning Phases o Problem conditions and actions required o Differences between geostationary and scientific missions Routine Phases o On board operations planning o Monitoring (ground station parameters, Beacon, derived parameters) o Deviation from normal operations and impact o Trouble shooting Data Handling (DH) Subsystem Subsystem overview o Specific Functions (Geostationary and Scientific Satellites) o Automated operations o Operation performed via ground control o CCSDS (influence on operations) o Software uploads o Deviation from normal operations and impact Time tagged commands o Sequence management Onboard data management o Payload data distribution o Storage o Memory dump AOCS Subsystem Operations Introduction to AOC subsystem o Components o Functions

, DLR o Structure Description of sensors (optical, inertial, etc.) Description of actuators (thrusters, wheels, magnetic torquer) Discussion of onboard control algorithm and complexity of the control unit w.r.t.: o the mission profile (commercial broadcasting, scientific, deep space, etc.) o levels of on-board autonomy o and required ground support Description of operational modes with reference to the current mission phase Discussion of failure detection and solution (on-board, on-ground) Examples of routine and contingency subsystem operations o Launch and Early Orbit Phase o Commissioning Phase o Routine Phase Tendencies of future AOC subsystem development Propulsion Subsystem Operations Typical Layout of a bipropellant propulsion system o Pressurisation System o Propellant System o Thruster Configuration o Pressure and temperature sensors Rules and Guidelines for subsystem operations o Operational Modes Autonomous operation Deterministic activities o FDIR Pressurisation system leaks Thruster failure Sensor failure o Real-time monitoring Outside activities During activities o Offline analysis Propellant budget Thruster performance Helium budget Hardware characterisation, e.g. pressure regulator, check valves o Performance prediction PWR Subsystem Operations Introduction Typical Layout o Power Generation o Power Storage o Power Control and Distribution o Redundancy Rules and Guidelines for subsystem operations

, DLR o Operational Modes and Associated Procedures o Ground Support Software Derived / Calculated Parameters Configuration and Range Checks Pre-Pass, R/T and Post-Pass Operations o Comparison of Different Missions GEO Missions vs. LEO Missions Scientific vs. Commercial Missions Past vs. Present Missions, and Future Trends THM Subsystem Operations Typical Layout o Passive Control Methods o Active Control Methods o Temperature Sensors o Analysis and Simulation Techniques o Redundancy Rules and Guidelines for subsystem operations o Operational Modes and Associated Procedures o Links to the Power Subsystem o Ground Support Software Derived / Calculated Parameters Configuration and Range Checks Pre-Pass, R/T and Post-Pass Operations o Comparison of Different Missions GEO Missions vs. LEO Missions Scientific vs. Commercial Missions Past vs. Present Missions, and Future Trends Repeater Subsystem Operations Typical Layout o Low Noise Amplifier o Down Converter o Input Multiplexer (Demultiplexer) o High Power Amplifier o Switching Matrix o Up Converter o Output Multiplexer Rules and Guidelines for subsystem operations o Launch and Early Orbit Phase (LEOP) No operations (Repeater is switched off) o In Orbit Test (IOT) Phase Initial Switch-on Test all nominal and redundant equipment Test all pathways Perform antenna mapping (Minimise the number of on-board switching and changes of configurations)

, DLR o On Orbit Control(OOC) Routine control of the repeater configuration Check-out of the correct position and attitude of the satellite by monitoring the link quality Scientific Instruments Operations Example: ROSAT low earth orbit Transmission of Telecommand (TC) o High Power (HP) commands; Low Power (LP) commands Power ON/OFF o Single commands Configuration of the Payload o Time-Tagged (TT) commands Low earth orbit Contact times and scheduled payload activities Monitoring of Telemetry (TM) o House Keeping Data checks (HK) on ground (R/T, NRT, Off-line) within the instrument or the S/C bus o Failure Detection, Isolation and Recovery (FDIR) Real-time check on board (normally S/C bus) for FDIR (example: CHAMP) o Real-time Checks during contacts for health monitoring o Near-Real-time Checks for monitoring data collected between two passes (quick-check) o Offline Checks done by the experimentator for decisions like 'replanning last task' Optional Interfaces o Time Information, Time correlation (example: ROSAT) o Keep alive or health signals for reactions within the experiment o Request for power off within the S/C bus because of serious problems within the experiment Operations o Routine Operations TT Ops (example: ROSAT) Mission planning cycle (example: ROSAT) o Long term planning o Short term planning o Replanning (very short term) Command Scheduling (example: ROSAT) o Contingency operations; errors detected by HK data during contacts and handled by: Procedures by the Ops Team On-call by the engineers On-call by the payload experts Access to the S/C manufacturer for S/W changes within the S/C bus

, DLR o Contingency Operations; errors detected by Science data and handled by: Replanning of tasks Reprocessing of data o Critical Phases: Launch and Early Orbit Phase (LEOP) Commissioning Phase / In Orbit Test Phase Contingencies o Documentation o ICD Interface Control Document Description for the exchange of data and information between control centre and payload experts Distribution of tasks and responsibilities o Requirements Documents Collection of external requirements according (examples): Telecommand database Number of commands per contact Number of TT s per 24 hours Telemetry database Number of TM Values Planning; scheduling; orbit; contact times; attitude manoeuvre; constraints; data dumps Interface S/C bus - Payload o Spacecraft User Manual Short overview (content) On Console Training Familiarisation on Console o Control Room Environment o Tools Intercom System and Voice Procedures o Login Procedure o Configuration o Subsets Telemetry System o Databases o TM Processor o Alarms- / N/A- and N/S-flagging o Operator Inputs Command System o Operational Modes/Uplink Patterns o Verification Methods (BD/AD Modes, A priori/a posteriori Conditions) Rules and Guideline for Routine Operations o Anomaly Processing o Logging and Reporting o Procedures as the leading element in operations o Scientific Missions and their pass profile (example: CHAMP) o Pre/Post Pass Activities o NRT Tools

, DLR o Offline Tools o GEO satellites and their profile Products and Sources o Orbit o Schedule o Science Simulation with the following key positions (role models): o Mission Operations Manager (MOS) o Command operator (CMD) o Subsystem expert (e.g. TCR or PWR) Two to three consoles involved Procedure for switching transponders Procedure for switching heaters Ground Segment Ground Station Networks Network Requirements and Characteristics o Spacecraft Operability and Safety Support Spacecraft with Telemetry and Command capability More than one station to allow longer contact periods with the spacecraft Required Locations (depending on orbit characteristics) Get tracking information for orbit determination High availability (Redundancy) o Support of required Frequency Bands, Modulations and Spacecraft characteristics Downlink in KU-Band, S-Band, X-Band etc. Support of the required Bandwidth (Uplink, Downlink) Different Uplink Modulations Other Antenna characteristics required for Satellites in Low Earth, Transfer, Geostationary, or Deep Space Orbits o Network examples NASA Deep Space Network (Goldstone, Canberra, Madrid) NASA Polar Network (Poker Flat, Wallops, McMurdo, Svalbord) ESA, CNES Networks Integrated DLR network (connecting different networks) Private Networks of Industry (LORAL, Hughes) Ground Station Design Tasks o Telemetry o Telecommand o Tracking Location

, DLR o Terrain o Soil o RF-Interference Main Components o Antenna o RF Equipment o Baseband Equipment o Time and Standard Frequency Equipment o Station Computer Network Design Aspects o Link Budget o Antenna Size o G/T o EIRP o Pointing, Autotracking o Component Location o Interface Antenna Site/Operations Building Electrical Power Supply o Requirements and Availability o Public Power Supply o Solutions for Non-Interrupted Supply Monitoring and Control o Time Behaviour o Network Aspects o Man Machine interface (MMI) Operational Aspects o Routine Operations, LEOP Support o Operations Personnel o Maintenance and Repair Control Centre Functions Communication Links o Public carrier links (ISDN, Leased lines) o Private Satellite links (roof to roof) o Link usage o Real-time data (Telemetry, Command) o Offline data (Telemetry, Tracking data, Orbit information, SOEs) o Voice, Video o Telex o Telephone o Gateway functions for different user and communication protocols SCC Internal Communication o Structure of the internal communication network LAN system o Different network components and nodes (Routers, Gateways, Firewalls, Data distribution and processing nodes) o Network security concept Hardware Components o Architecture and tasks of processors

, DLR o Voice system o Video system o Telephone system o Consoles o Power System o Printing and Xerox o Office Communication o Access Control and Security o Internal Communication Equipment o External Communication Equipment Software Components o Operating Systems (OPEN_VMS, NT, LINUX, UNIX) o Network Software (DECnet, TCP/IP) o Archiving- and Retrieval systems (GDS-Log) o Data Distribution (Routing, Flow Control) o External Gateway Software (EDI) o Process monitor- and control systems for ground equipment o Office Communication and Documentation Ground Station Network and SCC Mission Preparation o SCC and Network Specification Phase o Detailed Design Phase o Integration Phase o Testing and Verification Ground Station Network and Mission Execution Operational Aspects o Station interface handling o Redundancy switching o Software System Configuration o Pass Preparation o Controlling (Discrepancy Reports) o Accounting o Reporting o Scheduling