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This article provides a detailed overview of pre-launch operations, including mission phases, operations requirements, and ground system testing. It covers topics such as mission simulations, green card exercises, and end-to-end data flow tests.
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Pre-Launch Operations • Mark Lewis
Pre-Launch Operations • Overview • Mission Operations Phases • Operations Requirements • Pre-Launch Operations • Ground System Testing • FlatSat Environment • Mission Simulations • Green Card Exercises
Mission Operations Phases • Pre-launch Operations • End-to-End Data Flow Tests with All Ground System Elements • Extensive Flight Simulator and Classroom Training • Launch and Mission Simulations with Green Card Exercises • Launch & Early Orbit Operations • Initial Probe and Instrument Check-out, Deploy and Calibration • Maneuver Operations for Mission Orbit Placement • Normal Operations • Science Data Acquisition and Recovery • Maneuver Operations for Orbit Optimization • Contingency Operations • Recovery from Flight and/or Ground System Contingencies • Mission Termination Operations • Instrument Shutdown • Maneuver Operations to Initiate Re-entry
Pre-launch Operations • Pre-launch Operations • Procedure Testing and Validation • Launch & Early Orbit, Normal Operations and Contingencies • End-to-End Data Flow Tests with All Ground System Elements • Ground Stations, TDRSS, FlatSat and Flight Dynamics to MOC • Launch and Mission Simulations with Green Card Exercises • Practice of Contingency Detection and Recovery • Dress Rehearsals • Multiple Cycles of Launch Readiness Testing • FOT Training • Participation as Test Conductors in Mission I&T • Extensive Flight Simulator Training • Training on Usage of Various Software Tools • Classroom Sessions Given by Subsystems Engineers • Team Member Certification
Ground System Testing • Remote Access to I&T Facilities • Passive Remote Monitoring • Active Remote Operation • Procedure Development and Verification • Simulations • End-to-end Data Flow Testing
End-to-End Data Flows TDRS THEMIS Probe or FlatSat Berkeley Ground Station White Sands Ground Terminal Compatibility Test Van Secure Intranet I&T Facility At Swales Existing Secure Network Connection New Secure Closed IONet Connection GSFC NMC Existing Secure Open IONet Connection Berkeley Mission Operations Center Existing Secure Network Connection Wallops Flight Facility Different Routes for End-to-End Data Flows Between Probes and GDS Elements
FlatSat Environment • FlatSat • Swales Building Mission Simulator (FlatSat) • ColdFire CPU • Communications Card • Power Card • Load/Dev PC • VirtualSat (Spacecraft Dynamics and IDPU) • ACS Sensors/Actuator • Remote Access Available for SSL • Primarily After Swales Day Shift • Used Extensively for Testing Flight Software and Operations • FlatSat Will Move to SSL After Completion of I&T • Facilitate Launch and Contingency Simulations • Post-launch Testing of Flight Software Patches and New Procedures • On-going FOT Proficiency Testing
FlatSat Environment • FlatSat Hard-line Up-Down link ITOS S/C Command and Telemetry Realtime Control Load/DevPC COMM Card Power Card Spacecraft Processor ColdFire-5802 512KB E2PROM 512KB RAM Serial I/F Serial I/F Bus Avionics Unit (BAU) Connected Via Secure Internet 1-Hz Pulse Serial I/F VirtualSatPRO (S/C Dynamics IDPU Simulation) Berkley Ground Data System Digital & Analog Interfaces Ethernet ACS Actuator/Sensor I/O* * COTS for A/D-D/A conversion and IDPU I/F
Green Card Exercises • Examples of Green Card Exercises • Launch Related Anomalies • No Separation from Probe Carrier • High Probability of Re-contact Due to Off-nominal Probe Separation • Communications • Negative Telemetry Acquisition Via Ground Station or TDRSS • Multiple Probes Radiating, Causing Interference at Ground Station • Loss of TDRSS Contact • Command Uplink Carrier Down • Command and Data Handling • Commands Not Verified • State-of-health Limit Violations • Battery State-of-charge High or Low • Over-current or Under-voltage Conditions Detected • Temperature Sensors Indicate High or Low Limit Violation
Green Card Exercises – Cont. • Examples of Green Card Exercises - Continued • Processors, Memory and Flight Software • BAU or IDPU Reset • SSR Full at Beginning of Contact • Attitude Control System • Probe Attitude Off-nominal • Probe Spin Rate Out of Limits • Reaction Control System • Only One Latch Valve Can Be Opened • Thruster Appears to Be Leaking • Pressure Transducer Fails • Maneuver Execution • Maneuver Sequencing Not Executed On-board • Attitude Maneuver Halted by FDC Because of Detection of High Angular Rates • Thruster Pulse Firing Sequence Indicates Incorrect Phase Angle • Real-time Doppler Data Deviate from Predicted Track
Green Card Exercises – Cont. • Examples of Green Card Exercises - Continued • Instrument Power-on • Unsuccessful IDPU or Instrument Power-on • High-voltage Arcing in ESA or SST • Boom Deploy • Unsuccessful Magnetometer Boom Deploy • Radial or Axial Boom Deploy Procedure Not Executed On-board • Radial Boom Deploys Partially Only
Green Card Exercises – Cont. • Examples of Green Card Exercises - Continued • Ground Systems • Ground Station Down • Pass Missed Because of Network Outage • Command Workstation Failure During Contact • Flight Dynamics • Misidentification of Probes After Separation • Two-way Doppler Data from Ground Station Are Noisy • Orbit Determination Run Does Not Converge • Orbit Determination Yields Large Discrepancy Between Previous and New State Vectors • Attitude Determination Provides Erroneous Results
Green Card Exercises – Cont. • Examples of Green Card Exercises - Continued • Space Environment • Major Solar Storm – Potentially Affecting All Probes • Constellation Related Problems • Early Orbit Timeline Halted Because of Probe Anomaly • Probe Anomaly Requires Re-scheduling of Pass Sequence • FSW Bug Detected on One Probe with Potential to Occur on Other Probes • Simultaneous Anomaly on Two Probes • Staff Related Problems • ACS Engineer Missing During Maneuver Contact
Backup MOC • Backup MOC Possibilities Under Study • Probable Location in SMEX MOC at GSFC • Two Workstations Configured with S/W Necessary for Minimal Operations • ITOS, MPS, BEARS, BTAPS, SatTrack • Used in the Event SSL Rendered Un-useable For More than One Day • Backup MOC Workstation for FAST and RHESSI Has Just Been Installed in the SMEX MOC • Testing of This Backup Capability Scheduled to Begin on June 4, 2004