Development of James Web Space Telescope JWST

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Development of James Web Space Telescope (JWST)
Ground Systems Using an Open Adaptable
Architecture
Bonnie Seaton Alan Johns Jonathan Gal-Edd
NASA/GSFC Curtis Fatig GSFC/SAIC Ronald Jones
GSFC/ASRC Aerospace Francis Wasiak GSFC/General
Dynamics
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Observatory

• JWST mission under development by NASA (launch
  planned for 2013) with major contributions from
  European and Canadian Space Agencies. The mission
  is designed to address four science themes
• Observation of the first luminous objects after
  the Big Bang
• Assembly of these objects into galaxies
• Birth of stars and planetary systems
• Formation of planets and origins of life

• The JWST ground segment is an open adaptable
  architecture that will be used to support
  evolving requirements for a mission with 10-year
  development and operational cycles

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Open Adaptable Architecture

• JWST project requirement
• Same ground system will be used for science
  instrument and spacecraft development, IT and
  mission operations
• Common Systems real-time command and telemetry
  (CT) system, database
• Intent is to test-as-you-fly to identify
  problems early in the lifecycle
• System will evolve during 10 year development
  cycle prior to launch
• Open Adaptable Architecture Themes
• Support design upgrades and take advantage of new
  technologies
• Each component independent of other components
• Use ICDs, translators, ingest scripts for
  interfaces
• Select best products (real-time, analysis,
  automation, etc.)
• Implement using COTS rather than a home grown
  system
• Database is application independent
• Follow industry standards (CCSDS, OMG, IEEE,
  etc.)
• Phased approach for evolving ground system
• Phase 1 Development System
• Phase 2 Integration and Test (IT) System
• Phase 3 Operations System

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Ground System Implementation Decisions (1 of 3)
To deal with a project of this scope where
technology and software will evolve, the
following implementation decisions have been made

• Use the operational command and telemetry system
  for development and IT
• Use the same data and interfaces throughout the
  life of JWST
• Design modular components at the start of the
  development
• Provide upgrade path from the beginning of the
  process
• Explore automation technologies such as system
  messaging
• eXtensible Markup Language (XML)
• JWST XML compatible with Consultative Committee
  for Space Data Systems (CCSDS) XTCE
• Database is just the data, not tied to a
  particular application
• Allows for cross-referencing of command,
  telemetry and ops products
• Engineering data saved in a manner to be
  application independent

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Ground System Implementation Decisions (2 of 3)

• Project Reference Database
• Common area for all mission-related information
• Data independent of any system
• Configuration management of mission related
  information
• Onboard scripts
• Increased processing power of flight processor
  for event driven operations
• Use Java script COTS engine
• Use modular and common components onboard
• Data dictionary
• CCSDS File Delivery Protocol (CFDP)
• Reduce functionality needed at control center
• Use Deep Space Network to provide Level 0
  processing of science data
• Increase data reliability by providing a reliable
  file downlink protocol
• Use CCSDS standards for software and maintenance

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Ground System Implementation Decisions (3 of 3)

• Batch decommutated data
• Common generic format for all engineering data
• Engineering exchange format for other ground
  system components
• Data storage format prior to ingest into archive
• Engineering archive and trending
• Common engineering data store for the life of the
  mission
• Provide automated reporting
• Provide tools to analyze the status and
  performance of the JWST observatory

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Phased ApproachEvolution of the Ground System
Development and IT ground systems built around
eventual operations core components Flight
Operations System (FOS), and Project Reference
Database System (PRDS)
Phase 1 (Development)
Phase 2 (IT)
Phase 3 (Operations)
CT System
Load Dump Tools
CT System
Database
Database
Analysis System
Wavefront Sensing Control Exec (WFSC Exec)
Simulator
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Phase 1Development System

• Initial systems know as Science Instrument
  Development Units (SIDUs) are used during
  development of the science instruments and flight
  software
• In 2004, Eighteen SIDU systems built and deployed
  to GSFC JPL Abingdon, England Palo Alto,
  California Ottawa, Canada Munich, Germany
  Madrid, Spain and Cambridge, Canada

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Phase 2IT System

• In 2006/2007, the system evolves into an IT
  system with the deployment of seven Science
  Instrument Integrated Test Sets (SITS) which will
  be used for testing of hardware components
• First delivered May 2006 to Abingdon, England
• In 2008/2009, the final two IT systems,
  Instrument Test Support Systems (ITSSs), will be
  used for final integration testing

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Phase 3Operations Ground System

• The base Phase 1 development system will have
  evolved into the operations system
• The flight build of the operations system will be
  delivered in 2011, two years before launch

STScI Science Operations Center (SOC)
Operations Script Subsystem (OSS)
Observatory Simulators (OTB/STS)
Flight Operations Subsystem (FOS)
Project Reference DB Subsystem (PRDS)
JPL Deep Space Network (DSN)
GSFC Flight Dynamics Facility (FDF)
Wavefront Sensing Control Exec (WFSC Exec)
Data Management Subsystem (DMS)
Proposal Planning Subsystem (PPS)
Development, IT Systems Heritage
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Lessons Learned to Date
After four years of real-life experiences with an
open adaptable architecture, the JWST ground
system team has learned that

• Various vendors supplying different components
  keep the total system open and adaptable
• Interoperable plug and play concept works if ICDs
  are defined
• Central XML database is application independent
  which minimizes cost and is CCSDS XTCE compliant
• Open engineering and science data formats that
  are defined in an ICD allow for dissimilar
  systems to have access to the data without
  impacting the design
• CCSDS CFDP reduces amount of processing needed at
  end user site, increases data efficiency, and
  eases onboard recorder management problems
• Web-based technologies for user displays provide
  more flexibility, quicker development, and reduce
  long-term cost
• Evolving common CT and database systems for
  development through IT to operations is the best
  approach to ensure mission success
• Phased approach to system development allows for
  technology upgrades to occur naturally

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Full Scale JWST Model at the Goddard Space Flight
Center