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Developing a Common Telemetry Archiving Architecture. Presented at: Space Telescope Scientific Institute. Introduction. It is possible and desirable to support multiple missions with a common code infrastructure. - PowerPoint PPT Presentation
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Leeha Herrera
Nov 2005L Herrera
Developing a Common Telemetry Archiving Architecture
Presented at: Space Telescope Scientific Institute
Nov 2005L Herrera
Introduction
It is possible and desirable to support multiple missions with a common code infrastructure.For example, a common telemetry archiving system for creating a
long-term repository telemetry in packet format to support science and mission operations was developed.
With a common approach, development costs, staff, and testing can be shared across multiple missions.The initial cost is significant but is then drastically reduced for
subsequent missions.
Nov 2005L Herrera
Overview
• Background on JHU APL ground systems
• The Common Ground Approach• Assessment Product Line• Benefits, Issues, Results
Nov 2005L Herrera
JHU/APL Ground System Software Background
Nov 2005L Herrera
Single Mission Paradigm
• A Dedicated Teams was formed for each mission.+ No conflicts in resource scheduling across programs+ Responsive to the specific needs of the mission- Knowledge transfer & sharing between teams not inherently facilitated- Potential for redundant tasking
• A Snapshot of a previous system was used as basis for next mission No requirement to design for reuse+ A new mission did not have to start from scratch+ Users were familiar with overall functionality of applications- Not a simple or straight forward task- Modifications for some areas could be comparable to complete rework- Occasional need for complete rework or creation of new applications- Fixes or enhancements could easily shared between active missions
• Approximately the same efforts was required to provide the same fundamental functionality for each mission!
Nov 2005L Herrera
Single Mission ParadigmGround System
(in development)
Ground System
(production version)
Nov 2005L Herrera
Need for Change
JHU/APL was awarded with three NASA missions with overlapping schedules.
A Snapshot approach for re-use works for missions with dovetailed schedules, where teams can easily transition between projects.
We needed a solution to address limited resources for three active mission.
Would like to: Reduce overall development costs Reduce required staff per mission Improve quality
Improve estimations in scheduling and cost
Nov 2005L Herrera
The Common Ground Approach
Nov 2005L Herrera
Overview
The primary objective was to support the simultaneous development of multiple NASA missions.• Effort to develop applications that can be used on all
missions with little to no customization
Staff was reorganized into teams centered around “Product Lines.” • Reduce redundancy by dividing into common functional
areas vs. traditional mission-based teams• 4 Product Lines Created:
Assessment, Commanding, Planning, Telemetry
Nov 2005L Herrera
Simplified MOC Overview
Mission Operations Center
Planning(Commanding
Pre-Processing)Commanding
Assessment(Telemetry
Post-Processing)Telemetry
Deep SpaceNetwork
CLTU’s
Telemetry Frame
SFDU’s
Telemetry TransferFrames
Scripts
SupplementedTelemetry
Packets
SpacecraftUsers
CLCW’sMOC statusTelemetry
PlanningInputs
PlanningProducts
PlanningInputs
DataProducts
POC Commanding
POC or SSC Data Processing
WrappedTelecommandPackets
TelemetryPackets
STEREO Ground Software Peer Review: Ground Software Presentation – P. Mckerracher 10/4/2002
Nov 2005L Herrera
Initial Steps and Planning
The legacy code was evaluated for reuse.• Identify adaptable areas of code
A design was established for a new code infrastructure to handle variations in missions but support common core development.• Establish approach to encapsulate mission specific details• Definition of base classes to support new software pattern:
Parallel Classes• Used across all functional areas for all missions
Risk areas were identified.• Example: Telemetry Archiving Architecture
Nov 2005L Herrera
Cartoon Overview
+ =Generic
MissionY
MissionX
MissionZ
Mission…
Nov 2005L Herrera
Code Organization
Parallel Class PatternEx: Other classes use the TelemetryPacket class without knowing which
implementation it is.
Classes abide by the interface defined in the generic version.
The Configuration Management Tool associates the correct version of classes for a particular build.
CCSDSTelemetryPacket
(generic)
CCSDSTelemetryPacket(MESSENGER)
CCSDSTelemetryPacket
(STEREO)
Common GroundSW
Nov 2005L Herrera
Assessment Product Line
Nov 2005L Herrera
Assessment Charter
Encompasses all activities and applications used to archive, play back, and interpret telemetry for assessing spacecraft health and state, identifying trends, and providing telemetry data to external processes and customers for further analysis and processing.
Primary users of the data products include Subsystem Developers, Guidance and Control (G&C) analysts, the Integration & Test team, and the Mission Operations team. The primary users of the data access libraries and higher level data access tools are MOC and testbed software developers and G&C analysts.
Responsible for providing historical data from telemetry (e.g., command histories, voltages, temperatures) in forms appropriate for the tasks being performed by its customers (e.g., trend analysis for MOPS). It is additionally responsible for providing access tools in the form of software libraries for use by developers and stand-alone utilities for data consumers.
Nov 2005L Herrera
AssessmentCSCI
GSE Clients1:N
Archived Telemetry
Ancillary ProductsArchive Files
Files Affected FileIDR File
Archived TelemetryPackets
TelemetryCSCI
Archived Telemetry
Telemetry Packets,archive_server Directives
PlanningCSCI
Archived Telemetry
Assessment CSCI Context Diagram
SOC
archive_serverDirectives
archive_serverDirectives
DSMS
Cmd RadiationTimes Files
FrontEndCSCI
Cmd RadiationTimes Files
MOPs/ I&TUsers1:N
archive_serverDirectives,
Requested PointsFile
Archived Telemetry, Decommutated Points
Plots
archive_serverDirectives
LHerrera 06/03
Context Diagram
Nov 2005L Herrera
Goals for the Archiving System
Faster and consistent response and processing
A robust and flexible system• Key for development for multiple missions• Allow mission specific modifications• Lower maintenance costs and support time
Allow mission specific requirements and configurations
Support wide variety of users: Developers, I&T, MOps, Science Centers
Interface with EPOCH T&C
Nov 2005L Herrera
Key Design Decisions
Provide 3 types of access to dataReal-time, Instant Playback, Long-term Playback
Ability to “plug in” different processes to convert data from multiple sources and formats
Long running, file based processing vs. socketsApplications monitor input directories for new files
Archive built from real-time and off-line file processing
Access to available archive data while new data is added
Nov 2005L Herrera
System Data Flow
As ReceivedData Files
SortedArchive Files
Ground StationData Files
Front EndData Files
SorterdIndex & Data
Files
SorterdIndex & Data
Files
Real-timeData Client
Instant ReplayData Client
Playback Data Client
Data RouterReal-timeInterface
Spool datato files
InstantReplay
Interface
Sort &Create Index& Data Files
(filter)
DataConverter
DataConverter
Sort &Create Index& Data Files
(filter)
Merge newdata w/currentarchive
AssessmentProcesses
AssessmentProcesses
PlaybackInterface
for archiveddata
Ground Station
EPOCH
Nov 2005L Herrera
Benefits, Issues, Results
Nov 2005L Herrera
Component Based Architecture
Allows for flexibility in configurationEach mission can customize the system
Only necessary “plug in” components used
Small components focused on a single function have proven to be easier to develop, test, and maintain
Future components can be added to create additional layers of functionality
Nov 2005L Herrera
Archiving Architecture
Seamless merging of data from multiple sources with configurable filtering capabilities
Allows multiple points of access to data while processing it into the long term archive
Archive files can be used directly as data products to science centers
Ability to archive by ground receipt and/or spacecraft time
Efficient processing & quick turn around of large amounts of data
Nov 2005L Herrera
Common Ground Approach
• Challenges• Increased cost of initial development• Increased difficulty in coordinating resources across
simultaneous program schedules• Increased resources & staff over commitment on
occasion• Increased need to negotiate requirements among
multiple missions• Sophisticated configuration management system is
needed• Tightly manage modifications to “generic” classes• Complexity of system configuration remains an issue
Problems now reported due to configuration
Nov 2005L Herrera
Common Ground Approach
• Benefits• Shared cost of development across multiple NASA missions
• MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER)
• Solar-Terrestrial Relations Observatory (STEREO)
• New Horizons
• Reduced redundancy & capitalized on domain knowledge• Supports the needs of all current missions• Increased reliability through repeated testing & use• Increased familiarity among users• Solid base to free up resources to add new levels functionality
to be layered on top• Decreased development time & cost for subsequent missions
• A telemetry archiving system can be brought on-line for a new mission in a week
Nov 2005L Herrera
Comparison of Total Change Requests
Comparisons of GSW Errors
0
5
10
15
20
25
30
35
40
45
May-02 Dec-02 J un-03 J an-04 Aug-04 Feb-05 Sep-05 Mar-06
MESSENGER
STEREO
New Horizons
Comparisons of GSW Enhancement Requests
0
5
10
15
20
25
30
35
May-02 Dec-02 J un-03 J an-04 Aug-04 Feb-05 Sep-05 Mar-06
MESSENGER
STERENew Horizons
Comparisons of GSW New Requirements
0
2
4
6
8
10
12
May-02 Dec-02 J un-03 J an-04 Aug-04 Feb-05 Sep-05 Mar-06
MESSENGER
STEREO
New Horizons
Nov 2005L Herrera
Comparison Shifted for Development Phase
Comparison of Errors, MESSENGER Data Shifted
0
5
10
15
20
25
30
35
40
45
erro
rs p
er m
on
th
MESSENGER
STEREO
New Horizons
All relativeI&T starts
Comparison of Enhancment Requests, MESSENGER Data Shifted
0
5
10
15
20
25
30
35
enh
ance
men
ts p
er m
on
th
MESSENGER
STEREO
New Horizons
All relativeI&T starts
Comparison of New Requirements, MESSENGER Data Shifted
0
2
4
6
8
10
12
new
req
uir
emen
ts p
er m
on
th
MESSENGER
STEREO
New Horizons
All relativeI&T starts
Nov 2005L Herrera
What To Tackle Next
• Release of complete Ground SW Infrastructure
• Address next level of functionality for Assessment PL• Rely on a sound infrastructure of telemetry data flow &
archiving• Advance satellite/spacecraft State of Health (SOH)
assessment tools
• Search for solutions & technologies offered by other organizations• Identify emerging technologies that JHU/APL could help
cultivate