“Modeling the MER Mission” Chin Seah NASA Ames Research Center

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 2 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, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 3 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, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 4 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, ’91 Design of Mission Operations for Remote Sensing (Magellan Mission to Venus)

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 5 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, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 6 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.

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 7 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 Nominal Surface Tactical Timeline

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 8 Mission 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 Mar 2004 –MER A & B Operations overlap –Different Time Zones (2 on Mars, PDT at JPL) MER Organization

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 9 MER Organization Model

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 10 SAP PUL Scientist Plan SOWG Chair Plan TAP CE SOWG Chair SAP Plan PUL Engineer MAPGEN Plan MAPGEN Plan TAP PUL RSVP Plan PULRP RSVP Plan SIE RSVP Plan Uplink Tools Process Flow (Similar to traditional “Order Processing”)

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 11 MER Information Model

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 12 Clock, Schedule and Agents Mars Clock Object Broadcasts time when match Timeline Schedule Group Agent Timeline Object Reads Mars time Match Timeline with Mars time CIP Clock Object Schedule ObjectMission Operations Activity Conceptual Object Activity happens within Timeline Reads Associated Schedule Contains mission operations activities Is timeline over? Start next task? Do I start my shift? Contains timeline activities

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 13 MER Clock Model

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 14 Simulation of MER Clock Match Timeline

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 15 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 needed

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 16 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, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 17 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, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 18 Predicting Workflow Failure: SAP and MAPGEN Scenario Tactical Activity Planner Constraint Editor SOWG Chair MAPGEN Plan SAP SOWG Chair Plan MAPGEN Tactical Activity Planner SAP User Interface Observation 1 Activity 1 Activity 2 Observation 2 Activity 3 Without Sequence or Timing Constraints With Sequence and Timing Constraints Interface ≠ Specification

April 22, 2005Agent-Based Modeling & Simulation of Organizations and Work Practice 19 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