in-space crew-collaborative task scheduling
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In-Space Crew-Collaborative Task Scheduling. John Jaap Space Systems Operations Branch Mission Operations Laboratory Marshall Space Flight Center National Aeronautics and Space Administration 1-256-544-2226 [email protected]. Patrick Meyer Elizabeth Davis Lea Richardson. - PowerPoint PPT PresentationTRANSCRIPT
MOLThe Mission
Operations Laboratory
MOLThe Mission
Operations Laboratory
NASA MSFC Huntsville, Alabama
In-Space Crew-Collaborative Task Scheduling
John JaapSpace Systems Operations BranchMission Operations LaboratoryMarshall Space Flight CenterNational Aeronautics and Space [email protected]
Patrick MeyerElizabeth DavisLea Richardson
MOLThe Mission
Operations Laboratory
Chart 2NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Presentation Outline Introduction
Light-time delays Interplanetary internet Message bus Collaboration defined Integration
Concept of operations Widespread collaboration Collaboration on final schedule
Collaborative scheduling software Equipment mode modeling Task modeling Automatic scheduling Mixed-initiative scheduling Resources, conditions, and autonomous systems Terminology and standards User interfaces
Conclusion
MOLThe Mission
Operations Laboratory
Chart 3NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
IntroductionNASA has a vision to send humans to the moon and Mars. These missions are long and stressful.
The astronauts need to participate in scheduling.
The astronauts need autonomy. Quick response to anomalies Extended loss of communication
Technological advances are available to help. Delay-tolerant networks Remote-access planning and scheduling systems
♦ 18+ months♦ Earth only a point of light
♦ 4+ months return time♦ No voice conversations with earth
♦ Meet personal preferences♦ Have a sense of control over their own actions
♦ Understand reasons for task times
MOLThe Mission
Operations Laboratory
Chart 4NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Light-Time Delays (to Mars) Close approach is
56x106 km or3.1 minutes (one way).
Far retreat is400x106 km or22.2 minutes (one way).
The earth overtakes Marsevery 26 months.
Relay satellites can help with solar occultation and the delay-tolerant network. Diagram shows a relay satellite
trailing the earth by 90 degrees
MOLThe Mission
Operations Laboratory
Chart 5NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Communications for Mars Exploration Interplanetary internet
Path known even whendestination is unavailable
Long time delays expected Store-and-forward a good solution
Message bus Publish / subscribe (one-way communication) Standard infrastructure, standard message protocol
General name:Delay-Tolerant Network
MOLThe Mission
Operations Laboratory
Chart 6NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Collaboration in General
Passive collaborationBased on a concept of operation. Example: guards who work at different gates to ensure that only ticket holders enter the arena.
Of course, a special concept of operations is required.
Text Messaging
Working jointly to produce a product or attain a goal.
Interactive collaboration Face-to-face Teleconferencing and web conferencing Custom software Instant messaging and chat rooms File transfer Electronic forums Electronic mail Postal mail
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Chart 7NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Enabling Principles for Collaboration
The contributions of one collaborator will not invalidate the contributions of another. This includes the crew’s contributions.
Collaborators need only minimum expertise in the knowledge realm of other collaborators.
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Chart 8NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Concept of Operations
Widespread collaboration on preliminary timeline
(including crew)Crew / scheduling cadre
collaboration on final timeline
MOLThe Mission
Operations Laboratory
Chart 9NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Contributors to Widespread Collaboration on Preliminary Timeline Task experts –
First-hand knowledge about the tasks to be done and how to order the tasks to accomplish the goals.
Hardware and systems experts – Detailed knowledge about how the hardware performs and how it is integrated with systems.
Scheduling cadre – Knowledge of program goals. Produce the detailed timelines. Final tweaks to timeline.
Crew – First-hand knowledge of in-space situation, personal preferences.
Other contributors – Provide availabilities, predictions, and simulation of companion autonomous systems including robots / rovers.
TL developed on earth
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Chart 10NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Contributors to Final Timeline
Crew – Modify timeline based on in-space situation, personal preferences, etc.Modify models based on actual configurations.Delete tasks as desired / needed.Add tasks as desired / needed.
Scheduling Cadre – Verify actions of crew (when time permits).Modify models and timeline as needed.
TL finalized in space
Of course, custom planning and scheduling software is required.
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Chart 11NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
Planning and Scheduling Software
Key features –
♦ Comprehensive modeling schema that represents all the constraints
♦ Automatic scheduler that understands the models and produces a desired timeline
♦ Remote access to the scheduling system
♦ Human interface that is user friendly to all users including the crew
♦ Use of standard terminology
♦ Ability to perform over a delay-tolerant network
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Chart 12NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – Modeling Equipment mode modeling
Equipment and their modes are modeled independently of the tasks that use the equipment.
Resource and condition constraints are assigned in the equipment modes.
Models can define a hierarchy of constraints and alternate constraints.
Task network modeling Tasks use equipment in specified modes, variable durations. Temporal networks of tasks are defined using relationships
like during, after, overlap, cyclic, etc. Variable timing Optional tasks
Models are built on earth by experts. Occasionally they are
modified by the crew.
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Chart 13NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – Automatic Scheduling with an Incremental Engine
An incremental scheduling engine supports collaboration. Multiple remote users
can submit requests. Scheduling a request
doesn’t change what is already scheduled.
The engine can delete items on the schedule if nothing is invalidated.
The engine can replace items if nothing is invalidated.
Consistent with enabling principles.
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Chart 14NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – Mixed-Initiative Scheduling Engine
Mixed-initiative scheduling best used only by experts. Requires in-depth
knowledge of requirements Requires broad knowledge
of contents of TL Often has complex GUI. Displays comprehensive list
of endangered constraints. Can allow the user to override constraints. Can be used to invoke an incremental engine to add to
timeline.Not always consistent with
enabling principles.
MOLThe Mission
Operations Laboratory
Chart 15NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – Resources, Conditions, and Autonomous Systems
Resources(power, storage lockers, camera)
Conditions(sunlight, communications, weather)
Autonomous systems(robots, rovers, etc.)
During preliminary TL development, resources and conditions are predicted by earth-based software.
During final TL development, they are predicted by in-space software.
During preliminary TL development, autonomous systems are simulated.
During final TL development, the primary scheduler interacts (negotiates) with the autonomous systems schedulers. Example: robot is asked when it is available for a task, the primary scheduler schedules the task, and sends a message to the robot to commit the TL.
MOLThe Mission
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Chart 16NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – Terminology & Standards Collaboration by many diverse contributors requires
standard terminology and standard methods. Crew collaboration and crew autonomy require standard
terminology and software. Current / historic scheduling community is fragmented.
Examples: Terminology:
State vs. condition Goal set vs. operational sequence vs. task network
Approach: Start and end events vs. task
duration Implicit resource usage
Standards bodies, such as the Consultative Committee for Space Data Systems (CCSDS), are available to apply their expertise in establishing,
negotiating, and documenting the needed data standards.
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Chart 17NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
P&S Software – User Interfaces
Collaboration requires good user interfaces. Experts in many diverse fields must become “virtual”
scheduling experts.Scheduling experts must be able to comprehend the
requirements entered by others.The crew must be
able to use any part.The crew will need
specialized userinterfaces.
MOLThe Mission
Operations Laboratory
Chart 18NASA MSFCHuntsville, Alabama
In-Space Crew-Collaborative Task SchedulingJohn Jaap 25 October, 2006
ConclusionWhen the earth appears as a mere point of light,
and round-trip communication delays exceed half an hour, the humans on the journey must have significant control over their
daily timeline and the timelines of their companion systems.
In a new concept of operations, multiple, dispersed, earth-based teams and the crew collaborate on a preliminary timeline. Once the preliminary timeline is uplinked, the crew will become the primary
contributors with minimal ground support.
Implementing this new concept requires software that is delay tolerant, supports multiple users, is remotely accessible,
uses standard terminology, and has good user interfaces.And a delay-tolerant network must be implemented.