Development of James Web Space Telescope (JWST) Ground Systems Using an Open Adaptable Architecture

Bonnie SeatonAlan JohnsJonathan Gal-Edd

NASA/GSFCCurtis Fatig

GSFC/SAICRonald Jones

GSFC/ASRC AerospaceFrancis 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:

1. Observation of the first luminous objects after the Big Bang

2. Assembly of these objects into galaxies

3. Birth of stars and planetary systems

4. 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, I&T and mission operations• Common Systems: real-time command and telemetry (C&T) 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 (I&T) System

• Phase 3: Operations System

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Ground System Implementation Decisions (1 of 3)

Use the operational command and telemetry system for development and I&T

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

To deal with a project of this scope where technology and software will evolve, the following implementation decisions have been made:

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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

JPLDeep Space

Network(DSN)

GSFCFlight

DynamicsFacility (FDF)

STScI Science & Operations Center (S&OC)

FlightOperationsSubsystem

(FOS)

DataManagementSubsystem

(DMS)

WavefrontSensing &

Control Exec(WFSC Exec)

ProposalPlanning

Subsystem(PPS)

OperationsScript

Subsystem(OSS)

ProjectReference DB

Subsystem(PRDS)

NIS

N

ObservatorySimulators

(OTB/STS)C&TSystem

Load & DumpTools

Database

C&TSystem

DatabaseAnalysisSystem

Simulator

Phase 1(Development)

Development and I&T ground systems built around eventual operations core components: Flight Operations System (FOS), and Project Reference Database System (PRDS)

Phase 2(I&T)

Phase 3(Operations)

WavefrontSensing &

Control Exec(WFSC Exec)

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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 2I&T System

In 2006/2007, the system evolves into an I&T 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 I&T systems, Instrument Test Support Systems (ITSSs), will be used for final integration testing

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Phase 3Operations Ground System

JPLDeep Space

Network(DSN)

GSFCFlight

DynamicsFacility (FDF)

STScI Science & Operations Center (S&OC)

FlightOperationsSubsystem

(FOS)

DataManagementSubsystem

(DMS)

WavefrontSensing &

Control Exec(WFSC Exec)

ProposalPlanning

Subsystem(PPS)

OperationsScript

Subsystem(OSS)

ProjectReference DB

Subsystem(PRDS)

NIS

N

ObservatorySimulators

(OTB/STS)

Development, I&T Systems

Heritage

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

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Lessons Learned to Date

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 C&T and database systems for development through I&T to operations is the best approach to ensure mission success

Phased approach to system development allows for technology upgrades to occur naturally

After four years of real-life experiences with an open adaptable architecture, the JWST ground system team has learned that:

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Full Scale JWST Model at the Goddard Space Flight Center