THEMIS Mission Operations Manfred Bester THEMIS Mission Operations Manager THEMIS Mission Operations Peer Review Mission Operations − 1 UCB, November 4, 2003
Mission Operations Overview − − − Mission Operations Concept Ground System Requirements Lessons Learned Ground System Design Mission Operations Center Software Tools Berkeley Ground Station Mission Operations Staffing Telemetry Recovery NTIA License IT Security THEMIS Mission Operations Peer Review Mission Operations − 2 UCB, November 4, 2003
Mission Operations Concept Space Segment − − − 5 Spinning Probes in High Earth Orbits Simultaneous Release from LV Initial Orbits Close to Nominal Mission Orbits of Probes 3 and 4 Probes 1, 2 and 5 Move to Nominal Mission Orbits Prior to First Tail Season Store and Forward Strategy for Science Data Recovery All Probes Share Same Frequency − Contact One Probe at a Time Ground Stations Berkeley Ground Station as Prime Facility − Wallops GN or Universal Space Network as Secondary − TDRSS SSA for Ascent, Maneuver and Contingency Support − Operations Centers THEMIS Mission Operations Peer Review − Mission Operations − 3 UCB, November 4, 2003 Mission and Science Operations Centers Co-located at U. C.
Ground System Requirements for the THEMIS Ground System − − − Support of Simultaneous Mission and Science Operations for 5 Probes Complete Flight Dynamics Support Including Maneuver Planning Automated Pass Scheduling Functions Secure Network Links to Local and Remote Ground Stations Completely Isolated Network Link for TDRSS Support Real-time Command Control Functions Generation of Command Loads Databases for Probe Configuration & Status and Telemetry History Web Based Tools for Probe Status Displays and Trend Plots Detection of Limit Violations and Anomalies Emergency Notification via Pagers and Email THEMIS Mission Operations Peer Review Mission Operations − 4 UCB, November 4, 2003
Lessons Learned from Previous Berkeley Missions − EUVE, FAST, RHESSI, CHIPS Lessons Learned from Existing Constellation Missions − − − Globalstar Iridium Cluster Consult with Operations Personnel Find Out How Other Constellation Missions Operate Consult with Scientists Working with Cluster Data Take Advantage of Ideas and Concepts and Lessons Learned THEMIS Ground System Design − THEMIS Mission and Science Operations − THEMIS Mission Operations Peer Review Mission Operations − 5 UCB, November 4, 2003
Constellation Operations Questions for Globalstar / Iridium / Cluster Operations Personnel − − − − − How are operations of a satellite constellation organized? How many engineers and other support staff are required and what are their team roles? Which software tools are used operationally? What types of databases are used and what are their benefits and shortfalls? How are individual spacecraft monitored and commanded? How are operational status and configuration of each spacecraft maintained? How are ground images of the flight software organized? How is the overall constellation organized and maintained? How are orbit maneuvers planned and executed? Are spacecraft grouped operationally, e. g. by functions or by orbit plane or otherwise? How are data flows organized? How are individual spacecraft distinguished for telemetry and commanding? Which spacecraft designators are used and how are they used? What types of communications are used between control centers and ground stations? Which operations functions are automated and to what extent? How are anomalies reported and tracked? How are contingencies handled? What is planned for end-of-life operations? What pitfalls or sources of confusion were encountered and how should they be avoided? What lessons were learned and what should be done differently? THEMIS Mission Operations Peer Review Mission Operations − 6 UCB, November 4, 2003
Globalstar Lessons Learned − Test Each Spacecraft Carefully Before Launch − − Test Flight Software Patches Carefully Prior to Uplink − − Save Operations Costs and Enhance Reliability Provide Diagnostic Tools − − Assembly Line Approach Caused Multiple Spacecraft to Lose Attitude Control Before Automated Uplink Process Could Be Stopped Employ Modern Automation Techniques − − Assembly Line Approach Led to Multiple Wrongly Wired Magnetometers Flexible Tools Allow Engineers and Scientists to Compare Trends Between Different Spacecraft Some Great Engineering Ideas Turned Out to NOT Be Useful − − Plan for Contingencies on Routine Basis in Daily Pass Schedules Plot Trends for Multiple Spacecraft on Top of Each Other Allow Operators to Set Their Own Limits Sophisticated Database to Track Anomalies Across Satellites THEMIS Mission Operations Peer Review Mission Operations − 7 UCB, November 4, 2003
Operations Org Chart All Aspects of THEMIS Operations Are Performed at UCB / SSL NASA / GSFC GNCD Provides Support in Form of Consulting THEMIS Mission Operations Peer Review Mission Operations − 8 UCB, November 4, 2003
Ground System Block Diagram THEMIS Mission Operations Peer Review Mission Operations − 9 UCB, November 4, 2003
MOC Expansion Expanded 900 ft 2 MOC Facility at SSL THEMIS Mission Operations Peer Review Mission Operations − 10 UCB, November 4, 2003
Mission Operations Center THEMIS Mission Operations Peer Review BGS Antenna, Equipment Racks and FOT Workstations at the Mission Operations Center Mission Operations − 11 UCB, November 4, 2003
Overview of Software Tools Tool Develop er Function Platform Comments GTDS GSFC Ephemeris Generation, Orbit Determination Solaris In Operation at MOC Already GMAN GSFC Maneuver Planning Solaris, Linux In Operation at MOC Already MSASS GSFC Attitude Determination Windows In Operation at MOC Already Sat. Track BTS Orbit Analysis, Pass Scheduling, Networking, Visualization Solaris, Linux In Operation at MOC Already ITOS Hammers Probe Command Control Solaris, Linux In Operation at MOC Already MPS GSFC Command Load Generation Solaris In Operation at MOC Already BEARS UCB Emergency Response System Solaris, Linux Under Development at SSL THEMIS Operations Peer. Task and Event Scheduling − 12 Review Mission Operations Solaris APGENMission. JPL UCB, at MOC In Operation November 4, 2003 Already
Operational Databases Probe Configuration and Status Database Relational Database − Complete State-of-health History in Raw Telemetry Units for Each Probe − Complete Probe Configuration History (Tables, ATS Loads, FSW Versions) − Support of Trend and Command History Analysis − Pass Scheduling Database Sat. Track Provides Automated Pass Scheduling Functions − Ingests Confirmed Schedules of Remote Facilities (NASA/GN, USN, Others) − Interfaces Between Databases − Scheduling System Needs to Know Various Probe Status Parameters THEMIS Mission Operations Peer Review Mission Operations − 13 UCB, November 4, 2003
Probe Identification Type of Probe ID CCSDS V 1 Command SCID (e. g. 0 x 151) Assign ed By Purpose WDC-A- Command R&S Verification Assignment Type Location Where Stored at MOC on Probe Permanent With Probe Bus Probe Specific ITOS & MPS Configuration Probe Uplink Card (Jumpers) Probe BAU EPROM CCSDS V 1 Telemetry SCID (e. g. 0 x 151) WDC-A- Telemetry R&S Verification Permanent With Probe Bus Probe Specific ITOS Configuration & Ground Station FEPs Satellite Catalog Number (e. g. 29501, Assigned after launch) Identificatio NORAD n of Orbital Elements Permanent With Probe Bus Flight Dynamics Object Database N/A International Designator (e. g. 2006 -001 A, Assigned after launch) COSPAR Internation / WWAS al & Reference NORAD Permanent With Probe Bus Flight Dynamics Object Database N/A Constellati Operations − 14 Mission Permanent on With Probe Ground System THEMIS Bus Operations Probe Mission. Name Peer Review (e. g. THEMIS 1 and UCB, November 4, 2003 N/A
Probe Identification Matrix Probe Bus Name CCSDS V 1 Command SCID CCSDS V 1 Telemetry SCID Satellite Catalog Number THEMIS 1 Red Probe 0 x 151 29501 2006 -001 A P 1 THEMIS 2 Yellow Probe 0 x 152 29502 2006 -001 B P 2 THEMIS 3 Green Probe 0 x 153 29503 2006 -001 C P 3 THEMIS 4 Blue Probe 0 x 154 29504 2006 -001 D P 4 THEMIS 5 Purple Probe 0 x 155 29505 2006 -001 E P 5 THEMIS SIM White Probe 0 x 156 N/A Simulator International Constellation Designator Note: Only the Constellation Designator in the last column will change as a result of a probe replacement. THEMIS Mission Operations Peer Review Mission Operations − 15 UCB, November 4, 2003
Usage of Probe Identifiers Telemetry File Naming Conventions Format: − FACILITY. PROBE_BUS_NAME. TLM_VCN. YYYY_DDD_HHMM SS. dat Examples: − BGS. THEMIS_1. TLM_VC 0. 2007_028_060312. dat − BGS. THEMIS_1. TLM_VC 1. 2007_028_060312. dat − BGS. THEMIS_1. TLM_VC 2. 2007_028_060312. dat − BGS. THEMIS_1. TLM_VC 3. 2007_028_060312. dat THEMIS Mission Operations Peer Review Mission Operations − 16 UCB, November 4, 2003
ITOS Requirements General ITOS Requirements − Same as with FAST and RHESSI (See ITOS Standard Documentation) Performance Improvements − Configuration Monitors Built Into ITOS Implementation of New Features Collected Suggestions from Flight Controllers and Other Missions − New Desirable Features for Constellation Operations − − − Batch Mode for Telemetry Processing (May Be Possible Already Via Scripting) Telemetry Server for Distribution of Data Streams to Multiple ITOS Clients Joined Status Displays for Multiple Probes New Features Hammers Is Planning to Incorporate Mission Operations Arrays of Mnemonics (1 -D or 2 -D) − 17 THEMIS Mission Operations Peer Review − UCB, November 4, 2003
ITOS Configuration Dedicated Workstations Basic Configuration Is One Dedicated ITOS System per Probe − Additional Flexibility Built Into System for Dynamic Allocation of Workstations − TLM/CMD Connections Initiated from ITOS to Ground Station Supporting Probe − Multiple Backup Systems − Future Options for System Automation Envision Upgrade Path Towards More Complex Future Missions − ITOS Connects to Sat. Track Gateway Server (SGS) − ITOS Specifies Mission (e. g. THEMIS) and Leaves Individual Object and Facility Unspecified − SGS Assigns Individual ITOS System to a Particular Pass Support − Routing of Telemetry and Command Connections Via Frame. Link or Netcat THEMIS Mission Operations Peer Review Mission Operations − 18 UCB, November 4, 2003 − ITOS in Turn Loads TLM/CMD Databases and Procs and Supports −
ITOS Page Layout Rules for ITOS Telemetry and Status Page Layout − Uniform Page Header − − − − Probe Identifier with Unique Color Coding UNIX System Time Probe System Time Uniform Page Layout (Sub-headers, Data Columns, Grouping of Parameters) Usage of SI Units Only (V, A, s, m, kg, G, N, …) Assigned Button Colors for Particular Functions Usage of Templates Incorporate Feedback from Flight Controllers THEMIS Mission Operations Peer Review Mission Operations − 19 UCB, November 4, 2003
Sample ITOS Page Standard Features: − Color Coding for Probe Identification − UTC and Spacecraft Clocks − Telemetry Update Status − Unified Color Scheme − Color Coding for Green, Yellow and Red Limits − Button Control to Start Additional Pages − Button Control to Start Configuration Monitors THEMIS Mission Operations Peer Review Mission Operations − 20 UCB, November 4, 2003
TLM & CMD Naming Conventions Rules for Telemetry & Command Naming in ITOS Database Identify Subsystems in Telemetry Mnemonics and Commands − Use CLEAR Commands Only to Clear Counters or Status Flags − Use RESET Commands Only to Power Cycle or Reboot Subsystems − THEMIS Mission Operations Peer Review Mission Operations − 21 UCB, November 4, 2003
Mission Control Network Architecture All Ground Stations Connect to Different Ports on IP Router to Establish TLM and CMD Socket Connections Router Patches Socket Connections Through to ITOS Systems, Process Controlled by Automated Scheduling System THEMIS Mission Operations Peer Review Mission Operations − 22 UCB, November 4, 2003
Pass Scheduling Advanced Pass Scheduling Functions Sat. Track Generates View and Link Access Periods for All Satellite / Ground Station Combinations − Population of Scheduling Database with View and Link Access Periods − Scheduling Engine Calculates Support Priorities by Maximizing a Figure of Merit − Interfaces to Remote Scheduling Offices Allow for Automated Schedule Exchange − Submission of Proposed Straw Man Schedule − Reception of Confirmed Pass Supports − Iterative Procedure to Satisfy As Many Constraints As Possible − Freeze Committed Passes − Extraction of Confirmed Multi-mission Schedule from Database − Generation and Distribution of Schedule Files (SMEX Schedule, SGS Timeline File) Mission Operations − 23 THEMIS Mission Operations Peer Review UCB, November 4, 2003 − Real-time Scheduling of Passes via SGS Client Connections −
Sat. Track Scheduling Engine Calculates Support Priorities Conflict Resolution Will Be Based on Calculated Priorities − Operators Have Override Privileges for Emergencies − Calculated Priorities Based on Various Constraints Geometric View and Dynamic Link Access Periods − Interference Avoidance When Using Multiple Ground Stations Simultaneously − Probe Status (Memory Fill, Anomalous Conditions, Emergencies) − Time Since Last Contact for Each Spacecraft or Probe − Minimum Number of Contacts Per Day and Per Orbit − Maximum Time Between Contacts for Each Spacecraft or Probe − Maximum Transmit Time Per Pass, Per Day and Per Orbit − Data Replay Requests − Assignment of Fixed Priorities in Special Cases THEMIS Mission Operations Peer Review Mission Operations − 24 UCB, November 4, 2003 − Ground Station Availability (Other Spacecraft Supports, −
Pass Scheduling System Multi-mission Pass Scheduling System THEMIS Mission Operations Peer Review Mission Operations − 25 UCB, November 4, 2003
Remote Probe Status Monitoring Sat. Track Interface to ITOS Data Point Server (DPS) − − − − Sat. Track DPS Client Program Connects to Sat. Track Gateway Server One Instance of DPS Client Can Handle Multiple Probes Simultaneously Receives Pass Schedule Information in Real-time Connects/Disconnects to/from ITOS Supporting a Pass for a Given Probe Connects/Disconnects Can Be Interleaved for Multiple ITOS Systems Polls Values for List of Mnemonics and Saves Values in Local Database Periodically Updates Probe Specific Web Pages Generates Constellation Overview Page with Hyperlinks to Pages for Individual Probes Probe Status (Overall Green/Yellow/Red Condition, Battery November 4, 2003 Mission Operations − 26 UCB, Charge, SSR Fill, Tank Pressure, Various Temperatures, Attitude, THEMIS Mission− Operations Peer Review
Probe Clock Adjustment Proposed Probe Clock Adjustment − − − ITOS Compares Frame Transmit and Receive Times and Adjusts Clock Delta in Real-time During Pass Supports: ΔT = Tframe received − Tframe transmitted − Trange delay ATS Loads Include Commands to Periodically Adjust Clock Drift in Small Steps Requires Time Stamping of Telemetry Transfer Frames on Probes and by All Ground Stations (Ideally with Accuracy of 1 ms) Requires Range Information from Sat. Track Gateway Server for Specified Time (e. g. Frame Receive Time at Ground Station) When Requested by ITOS Requires Certain Flight Software Features − − − Capability to Set Coarse UTC Offset to Mission Elapsed Time Capability to Set Fine UTC Offset (Small Delta to Coarse Offset) Capability to Add Small Delta Offsets from ATS Load to Eliminate Clock Drift THEMIS Mission Operations Peer Review − Mission Operations − 27 UCB, November 4, 2003 Scheme with Both Ground Controlled and ATS Controlled Options
Ground Controlled Clock Adjustment THEMIS Mission Operations Peer Review Mission Operations − 28 UCB, November 4, 2003
Attitude Determination Real-time, Ground-based and On-orbit Attitude Determination Slew Monitoring During Maneuvers for Fault Protection − Data Provided by Sun Sensor and Inertial Reference Units − Sensor Data Processed in Real-time − Cross-calibration of Sun Sensor with FGM Near Perigee − Post-pass, Ground-based Attitude Determination Required for Science Data Analysis − Data Provided by Sun Sensor and FGM − Determine Attitude Accurately for Selected Orbit Arcs and/or Back Orbits − Attitude Solution Obtained with MSASS − THEMIS Mission Operations Peer Review Mission Operations − 29 UCB, November 4, 2003
Attitude Determination Pre-flight Testing and Validation Representative Command Profile Required to Perform End-to-end Tests for All Operational Scenarios for Each Probe − Post-test Analysis of Virtual. Sat Archive Files and Captured Telemetry Used to Validate ACS Flight Software for Thruster Control, On-orbit Attitude Determination and Fault Protection − Captured Telemetry from Virtual. Sat Used to Validate Groundbased Attitude Determination Software − On-orbit Calibration Test Fire All Thrusters and Assess Attitude and Spin Rate Changes − Align Magnetometer to Probe Spin Axis With 0. 5 deg Accuracy − Average IRU Measurements to Determine Bias − Perform Trending Analysis to Determine Precession Versus Time − THEMIS Mission Operations Peer Review Mission Operations − 30 UCB, November 4, 2003
Orbit Determination Based on Two-way Doppler Tracking − − − Ground Stations Provide Tracking Data in Universal Tracking Data Format (UTDF) One Station Sufficient to Provide Required Accuracy (10 km at Perigee, 100 km at Apogee) Data from Multiple Stations Yield Better Solution UTDF Files Processed with GTDS to Obtain New Orbit Solutions New State Vectors Used in Turn to Generate Updated Planning Products Digital Range Measurement System Technology Demonstration During Second Year − Measures Round-trip Delay of Digital Data Stream − Sat. Track/ODT Performs DRMS Based Orbit Determination THEMIS Mission Operations Peer Review Mission Operations − 31 UCB, November 4, 2003 Functions −
DRMS Design THEMIS Mission Operations Peer Review Mission Operations − 32 UCB, November 4, 2003
DRMS Implementation DRMS Hardware Implementation − − − Use Dual PTP NTs for Simultaneous Probe Commanding and DRMS Operations Uplink Uses Two Subcarriers at 16 k. Hz and 128 k. Hz Downlink Uses Two Subcarriers at 1024 and 128 k. Hz Pseudo-random Sequence of 216 -1 Bits Transmitted at Rate of 32 kbps Unique Range Determination to 300, 000 km or 47 RE DRMS Software Development − − − Simultaneously Read Outgoing and Incoming Data Streams Perform Automated Shifting of Delay to Find Maximum Correlation Restrict Delay Search Once Delay Found with High Confidence Required BGS System Upgrades for DRMS Hardware (Linux Computer) for Signal Analysis Upgrade of Existing Backup PTP (Subcarrier Demodulator and Bit Synchronizer) THEMIS Mission Operations Peer Review Mission Operations − 33 − Additional Matrix Switch for Baseband Signal Routing UCB, November 4, 2003 − −
BGS Requirements RF Compatibility Close S-Band Forward and Return Link with Any Probe at Any Range, Using Appropriate Data Rates Circular Polarization (RHCP or LHCP) Figure of Merit (G/T) > 24. 0 d. B/K at 5 º Elevation Transmit Power 200 W (EIRP > 66 d. BW) Two-way Doppler Tracking Digital Range Measurement System as Technology Demonstration Data Compatibility BGS 11 -m Antenna THEMIS Mission Operations Peer Review Viterbi Plus Reed-Solomon Decoding and Error Correction CCSDS Transfer Frame Processing Telemetry Data Routing by Virtual Channel IDs Mission Operations − 34 UCB, November 4, 2003 Command Forwarding
BGS Upgrades Apogee Labs Doppler Tracking System Carrier Doppler Measurement System (CDMS) and Track Data Formatter (TDF) − Time Code Generator Needs 10 pps Output − ACU-21 C Hardware and Software Upgrades − Parallel Interface for Fast Angle Readout Transmit Chain Upgrade SSPA Upgrade to 250 W − Low-loss Transmit Coax Cable − Additional Fiber-optic Cables − Optional Receive Chain Upgrade − Replace LNAs to Improve G/T Pedestal Environment Monitor Backup Power Via Existing Generator and UPS THEMIS Mission Operations Peer Review Mission Operations − 35 UCB, November 4, 2003
BGS Control Software Upgrades Sat. Track/MCS Software Upgrades − − − Control Apogee Labs Model 7701 CDMS Control Apogee Labs Model 2208 TDF Control DRMS System Via Network Sockets Control Dual SSPAs via RS-232 Interfaces Read-out Second Environment Monitor in Pedestal Read-out Status from Multiple UPS THEMIS Mission Operations Peer Review Mission Operations − 36 UCB, November 4, 2003
Doppler Tracking Tests Rationale for Doppler Accuracy Tests − − − THEMIS Orbit Determination Based on Two-way Doppler Tracking Doppler Accuracy Difficult to Predict for THEMIS Ground System Configuration Doppler Signal Extracted from 2 nd Local Oscillator in Telemetry Receivers Perform Tests to Establish Baseline to Predict Accuracy of Range Rate Measurements as Function of CNR for BPSK and PSK/PCM/PM Modulation Predicted Accuracy Will Tell How Many Tracking Arcs Are Needed to Perform Orbit Determination for the THEMIS Mission Required Accuracy 10 km at Perigee and 100 km at Apogee Test Sequence Functional Checkout of Equipment THEMIS Mission Operations Peer RF Tests Mission Operations − 37 UCB, November − Long Loop Review with Unmodulated Carrier and Telemetry 4, 2003 −
Test Schematic Diagram for Doppler Accuracy Tests THEMIS Mission Operations Peer Review Mission Operations − 38 UCB, November 4, 2003
Sources for Doppler Errors Potential Sources for Doppler Errors Synchronization of Timing Signals Is Very Critical − All Reference Signals Need to Be Generated By the Same Source − − − Lack of Synchronization Causes Errors − − − 5 MHz RF Reference for Phase-lock Loops 10 pps Clock for Triggering Measurements IRIG-B Time Code for Time Tagging Measurements Lack of Synchronization Between 5 MHz Reference and 10 pps Clock Causes Doppler Bias and Large Fluctuations in Doppler Signal Lack of Accuracy in IRIG-B Time Code Causes Doppler Bias Receivers Need to Lock Cleanly − Receiver Firmware Can Cause False or Imperfect Lock Under Certain Conditions Related to Remote Control Functions False Lock Causes Large Doppler Bias − THEMIS Mission Operations Peer Review Mission Operations − 39 UCB, November 4, 2003
Loop-back Doppler Tests Initial Loop-back Tests Performed − − − − Unmodulated Carrier Signal Transmitted at Low Power from Test Dipole at Apex of 11 -m Reflector RHCP Receiver in BPSK Mode, 3 k. Hz Loop Bandwidth AGC Level in Receiver 20 d. B Recorded Tracking Data for 6 min Measured Average Range Rate: − 0. 00000470 km/s Measured Range Rate Error (1 -σ): 0. 00012869 km/s THEMIS Mission Operations Peer Review Mission Operations − 40 UCB, November 4, 2003
Loop-back Doppler Tests THEMIS Mission Operations Peer Review Mission Operations − 41 UCB, November 4, 2003
On-Orbit Doppler Tests Initial On-Orbit Test Performed With HESSI Spacecraft − − − HESSI Has a Transceiver – Two-way Doppler Tracking Not Possible TDF Was Configured for Two-way Mode in Preparation of Tests with FAST Graphs on Following Slides Are Therefore Not Scaled Properly Test However Demonstrates Functionality of System Brief Data Drop-out Occurred When Spacecraft Switched Antennas (2 nd Graph) THEMIS Mission Operations Peer Review Mission Operations − 42 UCB, November 4, 2003
On-Orbit Doppler Tests THEMIS Mission Operations Peer Review Mission Operations − 43 UCB, November 4, 2003
On-Orbit Doppler Tests THEMIS Mission Operations Peer Review Mission Operations − 44 UCB, November 4, 2003
Mission Operations Phases Launch & Early Orbit Operations Probe and Instrument Checkout − Maneuver Operations for Initial Orbit Placement − Contingency Operations − Normal Operations Science Data Acquisition − Maneuver Operations for Orbit Optimization − Contingency Operations − Mission Termination Operations Maneuver Operations to Initiate Re-entry − Instrument Shutdown − THEMIS Mission Operations Peer Review Mission Operations − 45 UCB, November 4, 2003
L&EO Operations Launch & Early Orbit Operations Delta II Launch Sequence with Release of Probes − Round Robin State-of-Health Monitoring − Initial Attitude and Orbit Determination − Uplink of First Set of Command Loads to Each Probe − IDPU and FGM Power-up With Pre-deployment Calibration − Deployment of Magnetometer Booms − Cross-calibration of Magnetometers While Probe Separations Are Still Small − Systematic Instrument Power-up and Check-out − Test Fire and Calibrate Each Thruster on Each Probe − Spin Up to 30 r. p. m. with Calibration of Tangential Thrusters as Byproduct − Decision of Probe Placement − Discrete Pairs of Apogee and Perigee Maneuvers for Placement into Final Mission Orbits (Reorientation – Continuous Burn – Reorientation Sequence) Operations − 46 THEMIS Mission Operations Peer Review Mission UCB, November 4, 2003 − Maneuvers Performed While in Contact with Ground Stations −
Launch & Early Orbit Profile 13 -Oct-2006 23 -Dec-2006 THEMIS Mission Operations Peer Review Mission Operations − 47 UCB, November 4, 2003
Maneuver Planning and Execution Determine Pre-maneuver State Vector and Probe Attitude − Perform Maneuver Analysis with Current and Target State Vectors − Verify Delta V Budget − Develop Detailed Thruster Firing Sequence − Perform Contact Schedule and Shadow Analysis − Validate Probe Configuration and Maneuver Sequence on Probe Simulator − Establish Two-way Communications with Probe − Turn off ESA and SST High-voltage Supplies, Place SST into Attenuated Mode − Uplink Command Sequence to Perform Reorientation and Orbit Maneuvers − Download and Verify Command Buffer − Verify Firing Attitude − Monitor Peer Review THEMIS Mission Operations Maneuver Execution in Real-time (Tank Pressure, Mission Operations − 48 UCB, November 4, 2003 Attitude, Temps. ) −
Typical Maneuver Sequence Flight Operations Functions Power Down Gyros Turn Off Transmitter Determine New Orbit and New Attitude Execute Burn Sequence Power-off Catalyst Bed Heaters On-Board Failure Detection/Correcti on (FDC) Logic (gyro rates, sunsensor attitude limits, etc) Aborts Sequence if Anomaly is Detected Power-up Gyro’s, Catalyst Bed Heaters (Pre-Heat) Verify CMD & TLM link via GN, TDRSS, USN, or DSN Verify Tank Pressure, General Probe Health & Safety, 2 Way Ranging Monitor Key Temperatures, Attitude, and State Vector Verify Gyro Performance, Catalyst Bed Heater Functionality, Propellant Tank Pressure, Valve/Fuel Line Temperatures & States, and Pre. Maneuver Attitude Verify Current Attitude via Sun Sensor Data Downlink On-Board CMD Buffer Compare Flight to Ground Reference Image to Verify Proper Sequence Load Upload TLM Table, Firing Sequence, & Downlink Rate Selection Periodic Long. Term Calibration of Pulse Timing and Thruster Performance “Look Ahead” Orbit Propagation Indicates Upcoming Maintenance Maneuver is Desired Current/Desi red Orbit/Attitude used in GMAN Specific Maneuver Events, Attitudes, and Durations Formulated Discrete Thruster Profile and Pulse Sequence Formed Discrete Stored Command Sequence Generated via MPS Offline Validation of Entire Stored Command Sequence Performed on Probe Hi-Fidelity Test-bed Ground Operations Functions THEMIS Mission Operations Peer Review Mission Operations − 49 UCB, November 4, 2003
Instrument Commissioning 1. IDPU Turn-on As Soon As Probe Power System Is Stable and Temperature Below Maximum Operating Limit, Verification of Nominal Voltages and Currents, Command Communications and DCB Functionality 2. FGM Turn-on, Power Verification and Uplink of Parameter Load for 32 Hz Bx, By and Bz, Verification of Sensitivity Control on Each Axis, Select Sensitivity 3. EFI Turn-on, Power Verification and Configuration for 32 Hz E & B Sample Rates 4. SCM Turn-on, Power Verification and Activation of Calibration Sequence 5. Magnetometer Boom Deployment With FGM at 32 Hz Real-time Science TLM 6. SST Turn-on After Initial Outgasing Phase, Power Verification, Highvoltage Ramp-up and Attenuator Functional Test THEMIS Mission Operations Peer Review Mission Operations 50 UCB, November 4, 2003 7. ESA Turn-on After Initial Outgasing−Phase, Power Verification, Cover
Normal Operations Mission Planning During Normal Operations Preparation of the Conjunction Season − Ground Station Contact Schedules − Probe Command Control Probe Health and Safety Monitoring − Recovery of Science and Engineering Data − Command Load Uplink Twice Per Week − Instrument Configuration and Data Trending − Attitude & Orbit Determination − Routinely Performed Multiple Times per Week Maneuver Planning and Execution Orbits of Probes 1, 2, 5 Adjusted Few Times Per Year to Optimize Conjunctions − Orbits of Probes 1 & 2 Adjusted Annually to Counteract Lunar THEMIS Mission Operations Peer Review Mission Operations − 51 UCB, November 4, 2003 Perturbations −
MOC Staffing During Launch & Early Orbit Operations − − − UCB Flight Operations Team 24 Hour Staffing with Prime and Secondary Shifts Critical Commanding During Prime Shift Only Swales and UCB Engineering Team on Console During Prime Shift Instrument Scientists on Console During Instrument Commissioning MOC Staffing During Normal Operations THEMIS Follows FAST / RHESSI / CHIPS Model − Normal Operations Eventually Run with 8 x 5 Staffing − Lights-out Operations During Off-hours Successfully Demonstrated − Transition to Autonomous Operations After First Tail Season THEMIS Mission Operations Peer Review Mission Operations − 52 UCB, November 4, 2003 − Attitude & Orbit Maneuvers Always Treated as Special −
Telemetry Requirements Baseline Requirements for Instrument and Probe Bus Data Recovery − − − Each Probe Accumulates Up to 750 Mbits of Instrument Data per Orbit Data Compressed by Factor of 1. 5− 2. 0 Prior to Transmission to the Ground Apply 12% Overhead for CCSDS Formatting, 14% for RS Code Symbols Resulting Science Telemetry Data Volume 480− 640 Mbits / Orbit / Probe Required Downlink Time 16− 21 min Orbit / Probe at Data Rate of 512 kbps Each Probe Bus Accumulates Up to 87 Mbits of Engineering Data per Orbit − Apply 12% Overhead for CCSDS Formatting, 14% for RS Code Symbols THEMIS Mission Operations Peer Review − Resulting Engineering. Mission Operations − 53 Telemetry Data Volume 111 Mbits UCB, November 4, 2003 / Orbit / Probe −
Science Modes & Data Compression Science Modes − − − Slow Survey (SS) Fast Survey (FS) Particle Burst (PB) Wave Burst (WB) Mode Control Via ATS and/or On-board Triggers Data Compression − − − − Selectively Enabled / Disabled Applied Prior to Downlink Segmentation into 64 Byte Input Blocks Output Blocks Are Variable in Length Relatively Short Block Size Minimizes Impact from Bit Errors Compression Factor of 1. 5 -2. 0 Achievable Depends on Instrument Data Type THEMIS Mission Operations Peer Review Mission Operations − 54 UCB, November 4, 2003
Link Analysis Command Link Telemetry Link Frequency 2234. 0 MHz Frequency 2057. 141667 MHz Modulation BPSK Modulation PCM/PSK/PM Probe Antenna Gain -3. 0 d. Bic Ground Station Antenna Gain Probe EIRP 2. 5 d. BW Ground Station EIRP (11 -m Antenna) Range Path Loss Polarization and Pointing Losses Ground Station G/T (11 -m Antenna) 20, 000 km 185. 5 d. B 1. 0 d. B Range Path Loss Polarization and Pointing Losses 24. 0 d. B/K 45. 5 d. B 66. 5 d. BW 197, 000 km 204. 6 d. B 1. 0 d. B Probe G/T -38. 6 d. B/K Data Rate 1024. 0 kbps Data Rate 1. 0 kbps Bandwidth 2048. 0 k. Hz Bandwidth 1. 0 k. Hz Coding Gain 0. 0 d. B Coding Gain RS + Rate-1/2 Convolutional BER 8. 0 d. B 10 -6 Required Eb/No 2. 5 d. B Predicted Eb/No 9. 5 d. B Implementation Loss 2. 5 d. B Link Margin 4. 5 d. B THEMIS Mission Operations Peer Review BER 10 -6 Required Eb/No 10. 5 d. B Predicted Eb/No 19. 2 d. B Implementation Loss 2. 5 d. B Link Margin 6. 2 d. B Mission Operations − 55 UCB, November 4, 2003
Telemetry Rates Downlink Mode Schedule Duration Range Modulation Data Rate Stored Science and Engineering Downlink 1 x / Orbit / Probe 30 min 750 – 15, 000 km BPSK 1, 024 kbps Stored Science and Engineering Downlink 1 x / Orbit / Probe 30 min 2, 500 – 20, 000 km BPSK 512 kbps Stored Science and Engineering Downlink 1 x / Orbit / Probe 30 min 10, 000 – 30, 000 km BPSK 256 kbps Stored Science and Engineering Downlink 1 x / Orbit / Probe 30 min 20, 000 – 40, 000 km BPSK 128 kbps 30, 000 – 60, 000 km PCM/PSK/P M 1. 024 MHz S/C 64 kbps 50, 000 – 75, 000 km PCM/PSK/P M 1. 024 MHz S/C 32 kbps 65, 000 – 100, 000 km PCM/PSK/P M 1. 024 MHz S/C 16 kbps Real-time Engineering Downlink with Ranging 1 x / Day / Probe 30 min Real-time 80, 000 – 150, 000 Engineering Downlink 1 x / Day / Probe 30 min THEMIS Mission Operations Peer Review Mission Operations − 56 km with Ranging PCM/PSK/P M 8 kbps 1. 024 MHz November 4, 2003 UCB, S/C
Pass Support Plan Baseline Probe Contact Schedule Day Number Modulo 4 Probe 1 Probe 2 Probe 3 Probe 4 Probe 5 1 Data Recovery 30 min Data Recovery 30 min 2 Tracking & Monitoring 30 min Data Recovery 30 min 3 Tracking & Monitoring 30 min Data Recovery 30 min Tracking & Data Monitoring Recovery 30 4 Blue: Required Passes for Recovery of All Telemetry Data at a Rate of 30 min min min 512 kbps Red: Additional Passes Available for Tracking and Probe Monitoring at THEMIS Mission Operations Peer Review Mission Operations − 57 UCB, November 4, 2003 Lower Data Rates
Ground Station Support Options − Option 1: − − − Berkeley, CA, 11 -m (Primary) Wallops Island, VA, 11 -m (Secondary TLM/CMD)) Poker Flat, Alaska, 11 -m (Possible Back-up TLM/CMD) Santiago, Chile, 9 -m (Secondary TLM Only) Hartebeesthoek, South Africa, 10 -m (Secondary TLM Only) Option 2: − − Berkeley, CA, 11 -m (Primary) Dongara, Australia, 13 -m (Secondary TLM/CMD) South Point, Hawaii, 13 -m (Secondary TLM/CMD) North Pole, Alaska, 13 -m (Back-up TLM/CMD) THEMIS Mission Operations Peer Review Mission Operations − 58 UCB, November 4, 2003
Pass Requirements Per Mission Phase L&EO 4 Months − First Year Science − Second Year Science − THEMIS Probe L&EO Passes First Year Passes 1 2 3 4 5 Total 120 120 120 600 92 183 365 365 1370 THEMIS Mission Operations Peer Review Mission Operations − 59 Second Year Passes 92 183 365 365 1370 UCB, November 4, 2003
Pass Schedule BGS & NASA/GN THEMIS Mission Operations Peer Review Mission Operations − 60 UCB, November 4, 2003
Pass Schedule BGS & NASA/GN THEMIS Mission Operations Peer Review Mission Operations − 61 UCB, November 4, 2003
Pass Schedule BGS & NASA/GN THEMIS Mission Operations Peer Review Mission Operations − 62 UCB, November 4, 2003
Pass Schedule BGS & NASA/GN THEMIS Mission Operations Peer Review Mission Operations − 63 UCB, November 4, 2003
Pass Schedule BGS & USN THEMIS Mission Operations Peer Review Mission Operations − 64 UCB, November 4, 2003
Pass Schedule BGS & USN THEMIS Mission Operations Peer Review Mission Operations − 65 UCB, November 4, 2003
GSFC/Code 450 Support NASA GN and SN Resource Requirements in PSLA THEMIS PSLA Reviewed by GSFC/Code 450 − PSLA Under Code 450 Configuration Control − Compatibility Test Van for GN/SN End-to-end Testing − Additional Documentation Requirements Detailed Mission Requirements – Draft at CDR − RF ICD (Ground to TDRSS) – Draft at CDR − Data Flows and Scheduling for Ground Testing & Mission Operations − Supported and Coordinated by GSFC/Code 450 Ground System Development − Support of Experiments with Berkeley Ground Station to Determine Accuracy of Two-way Doppler Tracking THEMIS Mission Operations Peer Review Mission Operations − 66 UCB, November 4, 2003
NTIA License Status Frequencies Tentatively Assigned by GSFC Spectrum Management Office − Identical Frequencies for All Probes − − − Telemetry: 2234. 0 MHz Command: 221 / 240 ∙ 2234. 0 = 2057. 141667 MHz Do. D Currently Reviews Frequency Assignment − BGS Interference Survey Has Been Performed – No Offending RF Sources − NTIA Forms Have Been Provided by All Ground Stations − Formal NTIA Stage 2 License Application Under Development − Application Will Be Submitted in Mid November 2003 − Stage 2 Approval With Confirmed Frequencies Expected by August 2004 − Transponders Are Long-lead Items−and Need to Be Procured 4, 2003 THEMIS Mission Operations Peer Review Mission Operations 67 UCB, November Sooner −
Network Plan & IT Security NASA Network Security Requirements Driven by NPG 2810. 1, Security of Information Technology GSFC IT Security Outlined in Document 290 -004, IONet Access Protection Policy and Requirements − Establishes IT Network Systems Security Measures and Controls for Access to Critical NASA Resources − Documentation Requirements − Information Technology Security Plan, Risk Analysis and Contingency Plan Closed IONet Security Compliance Dedicated, Isolated Network and Workstations for TDRSS Access − Configuration Control by System Administrator − Network Certification. Mission. Scanning 68 and Operations − THEMIS Mission Operations Peer Review UCB, November 4, 2003 − Personnel Screening −
Acronyms ATS Absolute Time Sequence BEARS Berkeley Emergency & Anomaly Response System BFDS Berkeley Flight Dynamics System CDMS Carrier Doppler Measurement System COSPAR Committee for Space Research DRMS Digital Range Measurement System FGM Fluxgate Magnetometer GMAN General Maneuver Program GMSEC Goddard Mission Services Evolution Center GTDS Goddard Trajectory Determination System IRU Inertial Reference Unit MSASS Multi-mission Spin Axis Stabilized Spacecraft RTS Relative Time Sequence SSPA Solid State Power Amplifier TAPS Trending and Plotting System TDF Track Data Formatter UTDF Universal Tracking Data Format WDC-A-R&S World Data Center A for Rockets & Satellites WWAS World Warning Agency for Satellites THEMIS Mission Operations Peer Review Mission Operations − 69 UCB, November 4, 2003
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