Post on 25-Dec-2019
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“Modeling the MER Mission”
Chin SeahNASA Ames Research Center
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Outline
• Mars Exploration Rover Mission• Mission Operations Modeling• MER Brahms Model• Brahms Model Affecting Design of Mission
Operations• Predictive Model of Mission Operations• Lessons Learned
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Mar Exploration Rover Mission“Find Past Existence of Water”
•• Mars Exploration Rovers (MER)Mars Exploration Rovers (MER)– Spirit (MER-A) at Gusev Crater
• Reached Mars on Jan 4, ‘04– Opportunity (MER-B) at
Meridiani Planum• Reached Mars on Jan 25, ‘04
– 90 day mission which was extended.•• Science PayloadsScience Payloads
– Panoramic Camera:• Providing the geologic context
– Rock Abrasion Tool• Grinding Outside of Rocks
– Mössbauer Spectrometer• Identifying Iron-Bearing Minerals
– Miniature Thermal Emission Spectrometer
• Identifying Minerals at the Site
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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What is Mission Operations?“The control of one or more information
gathering devices on board a vehicle in space and the associated operation of the
vehicle systems in order to support information gathering.”
Wall, S. & K. Ledbetter, ’91Design of Mission Operations for Remote Sensing
(Magellan Mission to Venus)
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Why Work Practice Modeling for Mission Operations?
• New designs for – Facilities– Organization– Processes
• Complex work system– Scientists and Engineers– 24*7– Multiple Time Zones– Data Systems (new & legacy)
• Design close to implementation stage
• Trial and error of design during Operations Readiness Tests
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Where did data for model come from?
• JPL’s Tactical Timeline in Excel spreadsheets, design specifications, software documentation, etc.
• Participated in Mission Design Team’s design sessions
• Interviewed people that were part of MER mission operations.
• Observed JPL’s Operational Readiness Tests.
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April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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What to model?• Organizational Structures and Roles• Operational procedures for roles• Engineering and Science decision
making and planning• Rover on Mars
– Receive commands from Earth (Uplink)
– Command execution– Science Payload/Instrument
• Capture of Science data– Send data back to Earth (Downlink)
• Flow of Mission data– From Downlink to Uplink to
Downlink of science and engineering data
– Creation, flow and use of intermediate data
– Communication between people, and between people and systems
• Uplink rover command generation
Activ ity Name Location 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8 9
UHF Passes MGS Odyssey MGS Odyssey
DTE Sol n-1 DTE period DFE
Night T ime Rover Operations Night T ime Rover OperationsSleep Wakeup
Pre-Comm Session Sequence Plan Reviews
Sol n-1 Day Sequence Plan Review SMSA Sol n-1 Day Sequence Plan Review
Science Sol n Context Meeting 264-550 Science Sol n Context Meeting
Sol n-1 Night Sequence Plan Review SMSA Sol n-1 Night Sequence Plan Review
Real-T Ime Monitoring SMSA Real-T Ime Monitoring Real-T Ime Monitoring
Downlink Product Generation
Telemetry Processing Telemetry Processing
Image Processing Image Processing
Tactical Science Assessment/Observation Planning 264-550 Tactical Science Assessment/Observation Planning
Science DL Assessment Meeting 264-550 Science DL Assessment Meeting
Tactical End-of-Sol Engr. Assessment SMSA Tactical End-of-Sol Engr. Assessment
Engineering Skeleton Activity Plan Update 264-425 Engineering Skeleton Activity Plan Update
TDL/TAP/TUL Session 264-425 TDL/TAP/TUL Session
DL/UL Handover Meeting 264-450 DL/UL Handover Meeting
SOWG Meeting 264-550 SOWG Meeting
Activity Refinement / Sequence Assignment264-425 Activity Refinement / Sequence Assignment
Uplink Kickoff 264-425 Uplink Kickoff
Activity Plan Integration & Validation 264-425 Activity Plan Integration & Validation
Sequence Plan Roundtable 264-425 Sequence Plan Roundtable
Sequence Development 264-425 Sequence Development
Activity Plan Approval Meeting 264-425 Activity Plan Approval Meeting
Integrate & Validate Sequences 264-425 Integrate & Validate Sequences
Master/Submaster Walkthru 264-425 Master/Submaster Walkthru
Command & Radiation Approval 264-425 Command & Radiation Approval
Margin Margin
Sol n Radiation SMSA Sol n Radiation
Nominal Surface Tactical Timeline
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Mission Operations at JPLMission Operations at JPL– 50 Science Team Members– 30 Engineering Team Members
• Two Rover Teams (MER A & B)– 25 STM & 15 ETM per Rover Team
• Two Shifts per Martian Day/Sol– Shift handovers
• 4 floors within building• 90-Sol Minimal Mission Duration
– Jan 2004 - Mar 2004– MER A & B Operations overlap– Different Time Zones (2 on Mars,
PDT at JPL)
MER Organization
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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MER Organization Model
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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SAP
SAP
SAP
SAP
PUL
Scientist
Scientist
Scientist
PlanPlan
PlanPlan
PlanPlan
SOWGChair PlanPlan
TAP
CE
SOWGChair
SAP
SAP
PlanPlan
PlanPlan
PUL
Engineer
MAPGEN
PlanPlan
MAPGENPlanPlan PlanPlan
TAP
PUL
RSVP RSVP
PlanPlan PlanPlan
PUL
RP
RSVP
PlanPlan
SIE
RSVP
PlanPlan
Uplink Tools Process Flow(Similar to traditional “Order Processing”)
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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MER Information Model
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Clock, Schedule and Agents
Mars Clock Object
Broadcasts time when match Timeline
Schedule Group Agent
Timeline Object
Reads Mars timeMatch Timeline with Mars time
CIP Clock Object
Schedule Object Mission Operations Activity Conceptual
Object
Activity happens withinTimeline
Reads Associated Schedule
Contains mission
operations activities
Activity Name 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8 9
UHF Passes MGS Odyssey MGS Odyssey
DTE Sol n-1 DTE period DFE
Night Time Rover Operations Night Time Rover OperationsSleep Wakeup
Pre-Comm Session Sequence Plan Reviews
Sol n-1 Day Sequence Plan Review Sol n-1 Day Sequence Plan Review
Science Sol n Context Meeting Science Sol n Context Meeting
Sol n-1 Night Sequence Plan Review Sol n-1 Night Sequence Plan Review
Real-TIme Monitoring Real-TIme Monitoring Real-TIme Monitoring
Downlink Product Generation
Telemetry Processing Telemetry Processing
Image Processing Image ProcessingTactical Science Assessment/Observation Planning Tactical Science Assessment/Observation Planning
Science DL Assessment Meeting Science DL Assessment Meeting
Tactical End-of-Sol Engr. Assessment Tactical End-of-Sol Engr. Assessment
Engineering Skeleton Activity Plan Update Engineering Skeleton Activity Plan Update
DL/UL Handover Meeting DL/UL Handover Meeting
SOWG Meeting SOWG Meeting
Uplink Kickoff Meeting Uplink Kickoff Meeting
Activity Expansion and Review Activity Expansion and Review
Activity Plan Integration & Validation Activity Plan Integration & Validation
Activity Plan Approval Meeting Activity Plan Approval Meeting
UL1/UL2 Handover UL1/UL2 Handover
Build & Validate Sequences Build & Validate Sequences
Margin 1 Margin 1
Command & Radiation Approval Command & Radiation Approval
Margin 2 Margin 2
Sol n Radiation Sol n Radiation
Is timeline over?
Start
next
task? Do I start my shift?
Contains timeline activities
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April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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MER Clock Model
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Simulation of MER Clock
Match Timeline
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Issues of Modeling a Mission Operations
• Actual Work Practice was different from design– We know this from our theory of work practice– How useful is model in design?
• Unable to predict workflow failure– Round-Trip data tracking issue not identified
• This could have been identified and solved in model design but …
Much detail about mission data and systems neededApril 22, 2005 Agent-Based Modeling & Simulation of
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How Useful is Model in Design?
• Synchronizing Communications of Key Personnel– People could not verbally
communicate information because they needed to be in different places at the same time for meetings
• People’s work hours were too long– A shift was about 8 to 10
martian hours
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Other Uses of MER Brahms Model
• Procedures for Mission Operations Personnel• Assist in Mission Operations Planning.
– Creation of huge paper poster• Analysis of Mission Operations
– Mars-based time versus Earth time (24 x 7 & 8 hours)
• Simulation Visualization– Timeline view of information on Rover Activity
Plan– Communication networks creation and growth
April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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Predicting Workflow Failure:SAP and MAPGEN Scenario
Tactical ActivityPlanner
ConstraintEditor
SOWGChair
MAPGEN
PlanPlan
SAP
SOWG Chair
PlanPlanMAPGEN
Tactical Activity Planner
SAP User Interface
Activity 3
Observation 2
Activity 2
Activity 1
Observation 1
Without Sequence or Timing Constraints
With Sequence and Timing Constraints
Interface � Specification
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April 22, 2005 Agent-Based Modeling & Simulation of Organizations and Work Practice
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What have we learned?• How to model Mission Operations Systems• Level of detail to model
– More narrow/deep or more broad/shallow• Use of BRAHMS?Representation
+ Mars time vs. Earth time+ Multiple MER teams+ Systems+ Information flow+ Plans and schedules
Usefulness for mission designers- Not easy to retrieve information- Not easy to change model- Difficult to model things- Difficult to determine needed level- Difficult what-if scenarios