Implementation of a Mission Planning System for an Interplanetary Mission

1
Implementation of a Mission Planning System for
an Interplanetary Mission
SpaceOps 2002

• Author E. Rabenau, NOVA Space Associates
• Co-authors M. Denis, ESOC
• P. Jayaraman, VEGA Plc

2
Contents

• Mission Overview
• Operations Concept
• Mission Planning Concept
• Mission Planning System
• Conclusion

3
Mission Overview - Science Goals

• Orbiter
• Global high-resolution photogeology
• Global spatial high-resolution mineralogical
  mapping of the Martian surface
• Global atmospheric circulation and
  high-resolution mapping of atmospheric
  composition
• Subsurface structure mapping down to permafrost
• Measurement of surface-atmosphere interaction
• Measurement of interaction of the atmosphere with
  the interplanetary medium
• Lander
• Search for evidence of life on Mars

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Mission Overview - Spacecraft

• Data Management
• Solid State Mass Memory

• Communication
• X-band HGA
• S-band LGa
• UHF (lander comms)

• Power
• Solar Panels
• Li-Ion Batteries

• AOCSM
• Star Tracker
• Reaction Wheels

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Mission Overview Ground Segment
Mission Planning System
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Mission Overview - Milestones

• Launch May/June 2003
• Near-Earth payload verification
• Lander ejection 5 days before arrival at Mars
• Mars Orbit Insertion December 2003
• Mars commissioning
• 2 months
• Mission duration
• Nominal 687 days (1 Martian year)
• Extension 1 Martian year

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Operations Concept

• First 'Flexi' mission
• Re-use of existing technology
• New methods for project management
• Reducing the time from concept to launch
• First mission to Mars managed operated by ESA
• Elliptical polar orbit
• Pericentre drift
• Orbit maintained in phase and period ('frozen
  orbit')
• Allows timing to be based on events rather than
  absolute time
• Allows pre-plan of science observations

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Operations Concept

• Off-line Operations
• Commanding via Master Timeline
• Maintain 2 days of commands in TL buffer
• Store forward TM Science
• Dump all data once per day
• Data management requirement due to
• Varying data rates (256 kbps gt 28 kbps)
• Dump interruptions due to
• Eclipses
• Occultations
• Science data takes

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Mission Planning Concept

• Optimize science return within constraints
• Leads to planning how to use the available
  resources
• From coarse resource allocation to more detailed
  feasibility checking
• Introduction of mission planning 'cycles'
• Long term planning (6 months)
• Medium term planning (1 month)
• Constraints and resource checking at short term
  (1 week)
• Last minute checks and scheduling (2 days)

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Long Term Planning

• Generation of a Master Science Plan
• Determination of flexible Science windows based
  on
• Tracking and orbit maintenance requirements
• Communication requirements
• Performed by Payload Operations Service (POS) in
  conjunction with Project Science Team and Science
  Operations Working Group
• Utilisation of a resource analysis checking tool

11
Medium Term Planning

• Fixing of the Pointing Requirements
• Flight domain checks (thermal power)
• Conflict-free and feasible flight dynamics
  timeline
• S/C attitude requirements can be met within
  resource envelop of spacecraft
• Generation of preliminary operations requests
• Preliminary constraints and resource checking
• Performed by POS, Flight Dynamics, Flight Control
  Team, Mission Planning Team
• Utilisation of Thermal and Power Simulation tool
  and Mission Planning System

12
Short Term Planning

• Detailed resource constraint checks
• Based on Operations Requests on an orbit by orbit
  basis
• Application of 'rules'
• Generation of Master Operations Plan
• Performed by Mission Planning System

13
Daily Planning, Scheduling Reporting

• Detailed operations requests for attitude, wheel
  off-loading and orbit maintenance
• Lander commands from the Lander Control Centre
• Detailed operations requests for memory
  management
• Availability of refined event times based on
  latest orbit data
• Generation of command schedule
• Uplink of telecommands
• Analysis of command history versus operations
  plan
• Utilisation of Mission Planning System, Mission
  Control System

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Mission Planning System

• New development based on ENVISAT MPS
• To be utilized during routine operations phase
  (after successful Mars commissioning)
• Rule-based constraint and resource checking
• Generation of command schedules for Spacecraft
  and Ground Station

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Conclusion

• Complexity of mission, science operations, S/C
  pointing requirements
• Need for an automated tool to facilitate
  constraints and resource checking during routine
  ops
• Planning detached from commanding with long lead
  times is possible because of frozen orbit concept

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Mission Overview Space Segment

• Spacecraft (Orbiter)
• Solar arrays battery pack
• High gain antenna in X-band
• Lander communication package
• Reaction wheels
• Solid State Mass Memory
• Beagle-2 Lander
• 6 months operations

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Mission Overview Ground Segment

• Mission control
• S/C operations from ESOC
• Central science data distribution
• Ground station
• New Norcia (Australia)
• Daily 8 hour passes
• Flight Dynamics
• Orbit prediction, attitude manoeuvres, orbit
  maintenance
• Mission Planning System
• Detailed resource and constraints checking
• Payload Operations Service
• Lander Operations Control Centre