ESAW 2009 Operations Planning for the Galileo Constellation
Steve Reed Stewart Hall SciSys UK Ltd.
SciSys UK Ltd., Methuen Park Chippenham, Wiltshire, UK SN14 0GB Tel. 01249 466466 Fax. 01249 466661 Steven.reed@scisys.co.uk www.scisys.co.uk
Introduction
Galileo
Europe’s own global navigation satellite system:
Guaranteed global positioning service Highly accurate Under civilian control
Spacecraft Constellation Planning Facility (SCPF)
Part of the Galileo Ground Control Segment (GCS) Operations planning of:
Thirty-plus satellites Five/Six ground stations Two control centres
It generates a “Short-Term Plan” of:
Contacts (ground to satellite communications) Tasks and Activities for scheduled execution
A typical week for Galileo consists of:
300+ satellite contacts 1,500 tasks 10,000 separately schedulable procedures and on-board commands Plan produced in just 10 minutes
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Galileo Mission Planning Characteristics
Multiple satellites to be managed, with large number of schedulable operations (requires high-degree of automation) Orbits result in highly irregular ground-station visibilities pattern Largely unconstrained operations placed on timeline for execution Operations are largely routine with no more than 4 satellite in “special” operations at any one time Must avoid constantly “optimising” the already loaded ground and on-board schedules of 30 satellites Require greater plan stability and performance than is achievable with an optimising constraint resolution algorithm
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Functional Overview
GMS Mid-Term Plan
Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30
Operator
Flight and Security Operations
Planning Request Definitions
Planning Requests
Handle Handle Planning Requests Planning Requests
Mid-Term Planning Request
Satellite Station Availability Visibilities
Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30
Contact Scheduling Rules
Special Contact Req.
Schedule Contacts Schedule Contacts
Planning Requests
Orbital Events
Contact Schedule
Task Planning Rules Task & Activity Definitions
Plan Tasks Plan Tasks
Contact Status Report
Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30
Constellation Plan
Operator
Planning Planning Application Application
Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30 Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30
Update Status Update Status
Task 1 10:40 Task 2 11:10 Task 3 12:45 Task 4 13:50 Task 5 15:30
Contact Plan
Short-Term Plan
Status Report
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Failure Tolerant Uplink Strategy
On-Board Schedule
x30
x5
Contact Procedure Load OB Schedule In-Contact Activities Activate Backup Contact
Contact Plan Ground Schedule: Procedures On-board Schedule: Telecommands
Automation
Periodic Short Term Plan Generation Merged into Active Schedules Planning Short Term Plan: Contacts, Ground and On-board Tasks
-
Time into Future
No re-planning is required to activate a backup contact
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Contact Scheduling
1. Initialize Data structures
2.Allocate exclusive contacts for special contact requirements
3. Allocate non-exclusive contacts for special contacts requirements
4. Schedule Routine and Backup Contact Requirements
5. Calculate contact extension Boundaries (earliest start and latest end)
6. Save Contact Plan
4. chedule Routine and Backup Contact Requirements S 4.1. For each Spacecraft – Derive one Routine Contact Requirement 4.3. For each Spacecraft – Derive one Backup Contact Requirement
4.2. For each Spacecraft – Place a Routine Contact
4.4. For each Spacecraft – Place a Backup Contact
While not scheduled all contact periods
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Service Oriented Design
Planning Request Service
Request-response service File exchange Strict XML definitions – easy to read, write and validate Single and batch request transactions. Configurable for a variety of sources
GMS MKMF GMS MUCF FDF Other SCPF SCPF MMI Commercial service security key management Mid Term Planning for mission impact requests Satellite manoeuvres and other flight dynamics At the other GCC site SCPF operator
Short-Term Plan (Schedule Execution Service)
Schedule programming Execution feedback File Exchange Strict XML
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Model Driven Development
The software has many structural code aspects:
in-memory model persistence model configuration model exchange formats
To achieve consistency the code all originates from an underlying UML data model This model defines the classes of data and their relationships All the structural code aspects have been auto generated from the model The model driven approach has simplified design updates by first updating the UML, regenerating the Java, compiling and reintegrating it.
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Applications MMIs
Developed from the Eclipse Rich Client Platform
Java Basic windowing MMI Stable and fast Platform portable Attractive presentation Very active development
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Progress to Date
SCPF has deliveries to ESA:
D1 – A partial implementation including
All computing hardware (racks, servers and workstations) Fully implemented database editing Prototype contact planning and scheduling (fully functional) Routine task scheduling Short Term Plan generation
D2 – A full implementation, D1 +
All interfaces fully implemented Final version of contact planning and scheduling Planning request processing Resource modelling, automatic conflict detection and resolution Report generation Facility monitoring and control functions
We are about to deliver the D2 system
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FIN
Questions?
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