THEMIS FDMO CDR Peer Review − Pre-Launch Operations 1 June 1-2, 2004

Pre-Launch Operations

Mark Lewis

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 2 June 1-2, 2004

Pre-Launch Operations

Overview• Mission Operations Phases• Operations Requirements• Pre-Launch Operations• Ground System Testing• FlatSat Environment• Mission Simulations• Green Card Exercises

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 3 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 4 June 1-2, 2004

Operations Requirements

REQUIREMENT DESIGN

GS.OPS-1. THEMIS Mission Operations shall support all phases of the mission.

Compliance. The THEMIS ground segment is designed to support all phases of the mission.

GS.OPS-2. A complete set of ephemeris and mission planning products shall be generated to support all mission planning functions, ground contact scheduling and generation of command loads for all probes.

Compliance. Software systems in the Flight Dynamics Center are designed to provide all mission planning and ephemeris products to support all mission operations and data analysis functions.

GS.OPS-3. Mission planning functions shall ensure that all probes are configured and operated according to specifications, and yield optimum science data while preserving fuel and maintaining adequate margins and probe health.

Compliance. The Mission Planning System (MPS) comprises capabilities to check for violations of operational constraints. Other software tools such as FreeFlyer are used to plan maneuver scenarios with optimum fuel consumption.

GS.OPS-4. Probe state-of-health shall be monitored during real-time pass supports. Post-pass telemetry playback shall be used to examine back-orbit data for limit violations.

Compliance. ITOS will be used to monitor probe state-of-health during real-time pass supports as well as with back-orbit data playback. Yellow and red limit violations are detected and flight controllers are notified in turn.

GS.OPS-5. Mission operations shall include data trending to establish baseline parameters and to uncover any developing anomalous conditions early on.

Compliance. ITOS provides data trending capabilities. In addition, a database system will be set up to store all probe telemetry data. A query system will allow for rapid data retrieval, including trend analysis and data plotting.

GS.OPS-6. Command loads generated on the ground shall be verified prior to upload.

Compliance. Command loads generated with MPS are verified by at least two flight controllers prior to uplink.

GS.OPS-7. All critical commands, table loads and flight software patches shall be verified on the probe simulator prior to upload.

Compliance. A probe simulator (FlatSat) will be provided to the flight control team to test all critical command sequences, tables loads and FSW patches.

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 5 June 1-2, 2004

Operations Requirements

REQUIREMENT DESIGN

GS.OPS-8. The orbit of each probe shall be determined with an accuracy of 10 km at perigee and 100 km at apogee based on two-way Doppler tracking data.

Compliance. Number of tracks and ground stations, and accuracy of equipment and software selected to achieve required performance.

GS.OPS-9. All orbit maneuvers shall be carefully planned and validated prior to execution.

Compliance. All orbit maneuvers are planned with GMAN and validated on probe simulator prior to execution. Mission operations plan will contain details.

GS.OPS-10. Attitude determination of all probes shall be ground based and shall be based on raw Sun sensor and FGM data. FGM data recorded near perigee shall be used to cross-calibrate the Sun sensor on each probe.

Compliance. GSFC/GNCD provided software tools MSASS and MTASS will be used to perform ground based attitude determination. UCLA will assist with calibration of FGM.

GS.OPS-11. All attitude maneuvers shall be carefully planned and validated prior to execution.

Compliance. All attitude maneuvers are planned with FreeFlyer and validated on probe simulator prior to execution. Mission operations plan will contain details.

GS.OPS-12. Probe anomaly resolution shall be conducted in consultation with pertinent subsystem engineers, instrument scientists and project management personnel.

Compliance. The contingency plan will describe steps to be taken for all foreseeable contingency situations and will describe roles of pertinent subsystem engineers, instrument scientists and project management personnel.

GS.OPS-13. All critical operations (separation, deployments, and maneuvers) shall be done in real-time contact of the ground system.

Compliance. Ground stations and TDRSS provide access to all probes for real-time monitoring and command execution during critical operations.

GS.OPS-14. THEMIS Mission Operations shall maintain the Probes spinning about the positive Z axis.

Compliance. Spin axis orientation and rate of rotation are verified using ACS sensors.

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 6 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 7 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 8 June 1-2, 2004

End-to-End Data Flows

I&T FacilityAt Swales

Berkeley Mission Operations Center

White SandsGround Terminal

Compatibility Test Van

GSFC NMC

New Secure Closed IONet Connection

Wallops Flight FacilityDifferent Routes for End-to-End Data Flows Between Probes and GDS Elements

BerkeleyGround Station

THEMISProbe or FlatSat

SecureIntranet

TDRS

Existing SecureNetwork Connection

Existing SecureNetwork Connection

Existing SecureOpen IONet Connection

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 9 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 10 June 1-2, 2004

FlatSat Environment

FlatSat

* COTS for A/D-D/A conversion and IDPU I/F

Ethernet

ITOSS/C Command and Telemetry

Realtime Control

ITOSS/C Command and Telemetry

Realtime Control

ACSActuator/Sensor I/O*

ACSActuator/Sensor I/O*

Hard-lineUp-Down link

Berkley Ground Data System

Connected ViaSecure InternetSerial I/F

Serial I/F Serial I/F

SpacecraftProcessorColdFire-5802

512KB E2PROM 512KB RAM

SpacecraftProcessorColdFire-5802

512KB E2PROM 512KB RAM

COMMCard

COMMCardPower

Card

PowerCard

Load/DevPCLoad/DevPC

Bus Avionics Unit (BAU)

VirtualSatPRO

(S/C DynamicsIDPU Simulation)

VirtualSatPRO

(S/C DynamicsIDPU Simulation)

1-Hz Pulse

Digital & Analog

Interfaces

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 11 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 12 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 13 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 14 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 15 June 1-2, 2004

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

THEMIS FDMO CDR Peer Review − Pre-Launch Operations 16 June 1-2, 2004

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