Georgia Tech Space Systems Engineering Conference

Ground System for the Solar Dynamics Observatory (SDO) Mission

Hun Tann Chris Silva NASA/GSFC Greenbelt, Maryland

November 8-10, 2005

Georgia Tech Space Systems Engineering Conference 1 Deep Space Systems GT-SSEC.C.5 SDO Mission Summary

SDO: Solar Dynamics Observatory Objective: SDO spacecraft intended to carry a suite of solar observation instruments to monitor and downlink continuous, real time science data from the sun and distribute to Science Operations Centers (SOCs) Launch Date: August 2008 Mission Duration: 5 years, 10 years of expendables Latitude: 102 W° Orbit: 36,000km Geo Synch Circular, 28.5º Inclination Launch Vehicle: Lockheed Martin Atlas V Launch Site: KSC GS Sites: SDO Dedicated Supporting Sites: USN, SN

Georgia Tech Space Systems Engineering Conference 2 Deep Space Systems GT-SSEC.C.5 Science Overview – Living with a Star

To meet the needs of the Living With a Star program and determine the drivers and diagnostics of solar activity and variability which affect Earth and humanity, the Solar Dynamics Observatory must:

• Provide nearly continuous coverage of solar activity • Provide coverage of the regimes (interior, photosphere, corona) in which the activity occurs • Provide sufficient data on the types of phenomena which impact Earth, near-Earth space and humanity • Observe solar variability over the relevant timescales (seconds to years)

Georgia Tech Space Systems Engineering Conference 3 Deep Space Systems GT-SSEC.C.5 Observatory Overview

Science Instrument Suite: AIA Instrument Module

• Helioseismic Magnetic Imager (HMI) EVE – PI: Dr. Phil Scherrer – Stanford University – Images the Sun’s helioseismic and magnetic fields to understand the Sun’s Propulsion interior and magnetic activity. HMI Module

• Atmospheric Imaging Assembly (AIA) – PI: Dr. Alan Title – LMSAL Spacecraft – Multiple simultaneous, high-resolution Bus Module images of the corona over a wide range of temperatures. Antenna Orbit X • Extreme Ultraviolet Variability Experiment (EVE) Booms Injection Y – PI: Dr. Tom Woods – LASP, University of Colorado Engine Z – Measures the solar extreme ultraviolet (EUV) irradiance to understand variations.

Georgia Tech Space Systems Engineering Conference 4 Deep Space Systems GT-SSEC.C.5 SDO Driving Requirements

• Continuous High Rate Science Telemetry Downlink – 150 Mbps Ka-band (Includes compression and overhead) – No Flight Recorder for On-board Science Data Storage • Continuous downlink (24x7) for life of the mission • Real-time Science Data Pipeline (1.4 Terabytes per day) • Ground system supports 30-day science archive with retransmission capability to SOCs • Redundant systems in data capture and delivery paths from Ground Station antennas to SOCs • Two dedicated 18-meter Ka-band Ground Station antennas • Dedicated High-speed, large bandwidth science data network • Automated Ground System operations • Very Strict Science Data Capture – HMI science observation opportunity – 95% capture; completeness – 99.99% – AIA science observation opportunity – 90% capture; completeness – 99.90% – EVE science observation opportunity – 90% capture; completeness – 99.60% – Science observation opportunities reduced by normal mission operations factors including Stationkeeping Maneuvers, Instrument Calibrations (off-pointing), Earth Occultation (eclipse), HGA Handovers, etc. • Remote Science Operations Centers (SOCs) – Dedicated SOCs located with investigator teams – SOCs perform real-time health & safety monitoring and commanding – Science data processing, storage and public access for life of mission

Georgia Tech Space Systems Engineering Conference 5 Deep Space Systems GT-SSEC.C.5 S-Band End-to-End Data Flow

CCSDS Packets over 1553

Spacecraft Subsystems CCSDS CADUs Command & Science Instruments S-Band OMNI Data Handling CCSDS Transponders System Commands Antennas Playback Data from Spacecraft Recorder

RF S-Band Downlink RF S-Band Uplink - 2 kbps 250 kbps - S/C Recorder Playback 67 kbps - Nominal Real-time 8 kbps - Contingency Only

CCSDS Packets

HMI H/K Data

HMI Commands HMI SOC Telemetry VCDUs AIA H/K Data AIA SOC AIA Commands Command MOC SDOGS CLTUs EVE H/K Data EVE SOC EVE Commands

Georgia Tech Space Systems Engineering Conference 6 Deep Space Systems GT-SSEC.C.5 Ka-Band End-to-End Data Flow

IM-PDUs over 1355 Spacewire

Telemetry Instrument Module (IM) VCDUs

HMI Raw Data HMI Electronics Optics Package I-Channel Ka-Band RF Spacecraft Transmitter Modulator Command AIA Raw Data AIA & 4 Telescopes Electronics & Q-Channel Amplifier Data Handling System EVE Raw Data EVE RF MEGS/ESP Electronics

High Gain RF Ka-Band Downlink Antenna 150 Mbps

HMI Data Files (~55 Mbps) HMI Data Distribution System (DDS) SOC File Retransmit Requests

Core System AIA Data Files (~67 Mbps) IF AIA File Retransmit Requests SOC Front End Science 30-day Teams P5-dayrocess Rawo r SDOGS TLM File VCDU EVE Data Files (~7 Mbps) Storage Storage EVE File Retransmit Requests SOC

Georgia Tech Space Systems Engineering Conference 7 Deep Space Systems GT-SSEC.C.5 SDO Ground System Architecture

Tracking Data Space Network S-Band: TRK & HK Tlm Acquisition Data (L&EO only) S-Band HK Tlm

CMD S-Band: TRK, Cmd & HK Tlm

SDO Ground Station Tracking Data

STGT S-Band HK Tlm Flight Dynamics S-Band: TRK, Universal Space S-Band RF & Facility SDO Cmd & HK Tlm Network FEP system CMD, Orbit Determination (Includes 72-hr storage) Acquisition Product Generation Ka-Band: Data 150 Mbps DDS FEP Same Interfaces Ka-Band Tracking Data Science Data (Incl. 120-hr as WSGT Ground Station RF system storage) OD Products S-Band: TRK, Cmd & HK Tlm Ka-Band: SDO Ground Station 150 Mbps Observatory Commands SDO Mission Operations Center Science Data WSGT Acquisition Data S-Band RF & FEP system Telemetry & Command Flight Dynamics Observatory HK Telemetry (Includes 72-hr storage) System System Tracking Data Maneuver Planning DDS FEP Ka-Band Mini Product Generation (Incl. 120-hr ASIST / FEDS MOC Status R/T Attitude Determination RF system storage) Telemetry Monitoring and Command Management Sensor/Actuator Calibration Control HK Data Archival Ka Science Data Ka Science Data HK Level-0 Processing Mission Planning Data Distribution DDS & SDOGS Station/DDS Control Ground Station Control System Integrated DDS Control Plan daily/periodic events System Status Station/DDS Status Create engineering plan Manager (Incl. 30-Day Science and Automated Operations Generate Daily Loads DDS & Ground Data Storage) Control Anomaly detection Station Control Integrated Trending Data Ack. & Retrans. Requests Data Ack. & Retrans. Requests WSC & Plotting System

AIA Science Data Alert Notification HMI Science Data (55Mbps) (67Mbps) EVE Science Data (7Mbps) System Stanford Univ. EVE SOC (Stanford, CA) LASP Science Data Capture (Boulder, CO) S/C Memory dumps Flight software loads Science Data Capture Simulated commands Simulated housekeeping telemetry HMI AIA JSOC Instrument Monitoring LMSAL & Control Flight Software (Palo Alto, CA) Maintenance Lab Instrument Monitoring EVE R/T HK Telemetry Science Planning and FDS Products FSW Support & Control Instrument Commands/Loads FLATSAT Tool Suite AIA R/T HK Telemetry/ Science Planning and FDS Products Instrument Commands/Loads HMI R/T HK Telemetry/ Science Planning and FDS Products Instrument Commands/Loads GSFC Georgia Tech Space Systems Engineering Conference 8 Deep Space Systems GT-SSEC.C.5 SDO Ground System Overview

• SDO Ground System Consists of 5 Major Elements: – Data Distribution System (DDS) - located in White Sands • Receives the science telemetry data, processes it into files and distributes them to the instrument teams in near-real-time. • Provides a short-term (30-day) storage capability and supports data retransmissions as needed. • Provides the remote monitor and control capabilities of the DDS and SDOGS, from the MOC through the DDS/SDOGS Interface Manager (DSIM) which is part of the DDS design – SDO Ground Station (SDOGS) - located in White Sands • Two dedicated 18-meter antennas and associated RF equipment and software to provide the ground to spacecraft link on a continuous basis for Observatory telemetry downlink and command uplink. – Mission Operations Center (MOC) - located at GSFC • Supports the traditional real-time Telemetry and Command (T&C) functions, which allows the Flight Operations Team (FOT) to monitor the health and status of the observatory and to control its operations. • Provides mission planning, trending and analysis, remote control and monitoring of DDS and ground station functions, and Flight Dynamics functions, including attitude determination and control and orbit maneuver computations and execution. – Three Science Operations Centers (SOCs) • Real-time Health and Safety monitoring and Command Control of instruments • Science mission planning • Science Data processing, analysis, archive, and distribution to user community – Communications Network • Provides connectivity between each of the ground system elements supporting all levels of data exchange and voice communications for SDO mission operations.

Georgia Tech Space Systems Engineering Conference 9 Deep Space Systems GT-SSEC.C.5 DDS Architecture Diagram

The primary function of the DDS is to continuously receive the high-rate science telemetry from the SDOGS Ka-band system and to deliver the science data to the SOCs in near real-time. Comprised of two major components: – Front End Processor (FEP) • Each FEP consists of a High Data-rate Receiver (HDR) and Virtual Channel Data Unit (VCDU)- Server – DDS Core System • Consists of Quality Compare Processor (QCP), Storage Area Network (SAN), and File Output Processor (FOP), and DDS/SDOGS Interface manager (DSIM)

TCP/IP Permanent SCP/IP Over Over DDS 30-Day T3 Network Gig Ethernet Core Online System Archive STGT Science Ops STGT-FEP 1 Temporary Retran Centers Online Mngr ACQ File Exchange Archive EVE SOC FEP File Near-Real time Data Ka-Band IN-SNEC LASP VCDU Output Retransmissions RF HDR Quality Boulder, CO Server Equip Compare Volume Mngr S-Band RF Archived Retran JSOC ACQ File Exchange Equip VCDU Mngr Files AIA SOC Temporary Near-Real time Data File Stanford U 5-Day VCDU Output Retransmissions Palo Alto, CA File Storage Quality Compare Volume Mngr

Retran ACQ File Exchange Mngr HMI SOC Near-Real time Data Stanford U WSGT-FEP 2 File WSGT Palo Alto,CA Quality Output Retransmissions Compare FEP Volume Ka-Band IN-SNEC VCDU Mngr RF HDR Server Equip Status Warm Files S-Band QCP SCP/IP Over RF Spare Warm OC3 Network Equip FOP Temporary Spare 5-Day VCDU Storage File Storage Area DSIM Network

Mission Operations Control Directives Center Status Packets GSFC, MD

Georgia Tech Space Systems Engineering Conference 10 Deep Space Systems GT-SSEC.C.5 DDS Front End Processor

• Front End Processor (FEP) – FEP HDR is an IN-SNEC CORTEX Series HDR-XL – FEP VCDU-Server is an Apple G5 – Two FEPs configured with each SDOGS antenna for redundancy – Both FEP HDRs receive the IF input from the SDOGS Ka-band system and perform signal processing including: • FEP HDR performs demodulation, Viterbi decoding, I & Q channel recombining, frame synchronization, pseudo-random noise decoding and Reed-Solomon error detection and correction – Prime FEP feeds VCDU files to DDS Core System QCP in near real-time – Redundant Backup FEP used for replays and failure recovery – Each FEP VCDU-server includes circular buffer with disk capacity for 5-days

Georgia Tech Space Systems Engineering Conference 11 Deep Space Systems GT-SSEC.C.5 DDS Core System

• DDS Core System – Quality Compare Processor (QCP) • Five QCPs (3 prime and 2 backup) Apple G5 X-servers • Nominally configured to receive two VCDU data streams, one from each Primary FEP • Performs VCDU-level comparison and archives science telemetry in files by Virtual Channel Identifier (VCID) – Storage Area Network • Level 5 Redundant Array of Independent Disks (RAID) • Consists of Four 16-TByte RAIDs (CoreData ATA 4200 (NexSAN)) • 30-day Temporary Online Archive Data (TOAD) system for storage of science data files • Permanent Online Archive Data (POAD) system for data accounting information – File Output Processor (FOP) • Five (3 prime and 2 backup) Apple G5 X-servers • FOP polls TOAD output directory for presence of new files • New files are queued for delivery to the SOCs • Science data files delivered using Secure Copy Protocol (SCP) • Acknowledgment protocol used to coordinate file delivery • SOCs can request retransmission of files within 30 days – DDS and SDOG Integrated Manager (DSIM) • Two (1 prime and 1 backup) Apple G5 X-servers • Function as the collection point and translator between the various SDOGS and DDS subsystems and the MOC T&C system for SDOGS and DDS monitoring and control

Georgia Tech Space Systems Engineering Conference 12 Deep Space Systems GT-SSEC.C.5 SDOGS Architecture Diagram

Georgia Tech Space Systems Engineering Conference 13 Deep Space Systems GT-SSEC.C.5 SDOGS Antenna Subsystem Overview

• The SDOGS is comprised of two 18-meter dual-feed (S-band and Ka-band) Antennas – Physically located approximately 3 miles apart – One located at the TDRS Whites Sands Ground Terminal (WSGT) – Second located at the TDRS Second TDRS Ground Terminal (STGT) – Each antenna site includes the following Ka-band and S-band systems • S-Band System Primary Components include: – S-band Tracking Receiver – Fiber Optic Assembly: contains fiber optic transmitters and receivers – RF Distribution Assembly – RF Converter Assembly: downlink signal is received at 2215 MHz, down-converted to a 70 MHz IF, and distributed to two redundant Range Receive Command Processors (RRCP) – RRCP: the RRCP is a single box design providing the wide-band receiver, PCM demodulator, bit- synchronizer, de-randomizer, Viterbi-decoder, frame-synchronizer, Reed-Solomon decoder, and CCSDS frame processing, storage, and distribution services – Operationally, both RRCPs will be configured to receive and perform S-Band signal processing, one configured as a Primary unit and the second as a hot-backup • Ka-Band System Primary Components include: – Ka Tracking Receiver – RF Down-converter: downlink signal is received at 26.5 GHz and down-converted to a 720 MHz Intermediate Frequency (IF) – Fiber Optic Assembly: transmits the 720 MHz IF to an RF Distribution Assembly – RF Distribution Assembly: splits and redundantly routes the Ka IF to two high data rate Front End Processors (FEPs)

Georgia Tech Space Systems Engineering Conference 14 Deep Space Systems GT-SSEC.C.5 MOC Architectural Diagram

Orbit Solutions Planning Requests

FDF FOT Tracking Data SDO MOC DPS RTS’s, TDRSS ATS Load Template Input Acquisition Tracking Data FOT Data Station Schedule MPS

External USN Acquisition Data Networks FDS Products FDS IFS Observatory HK Tlm IFS Observatory Commands Timeline, Integrated Print Orbit Info Tracking Data FDS Products DPS FDS Products S Acquisition Data D R/T & PLBK S/C Tlm Range Data, EPV’s FOT Calibration Requests O Flight S/W Loads IFS PDB Files, Simulated HK Telemetry Batch Cmd Files, Science G Command Loads Uplink Plan, SOC Reports SDO Flight Software T&C R Maintenance Lab Command History Rpt PDB Files, (FLATSAT) Observatory Level 0 HK Tlm Level 0 HK Tlm, O DPS Memory Dumps ASIST/FEDS Cmd History Rpt U Simulated Commands SOCs Observatory HK Telemetry N Instrument Commands D Observatory Commands XML data Observatory HK Telemetry Status ANS S Email Alerts T IFS A DDS & DDS Control PDB Files, T DDS Status Observatory Paging Msgs and Responses SDOGS SDOGS Control HK SOC Telemetry I SDOGS Status Staff Integrated Paging Msgs and FOT O Status Responses N Manager ITPS Staff Remote (DSIM) Users 3/31/05 Note: the MOC contains only one IFS and one DPS

Georgia Tech Space Systems Engineering Conference 15 Deep Space Systems GT-SSEC.C.5 MOC Major Components (1 of 2)

• Telemetry and Command (T&C) Subsystem – MOC T&C functions are provided by Advanced Spacecraft Integration and System Test (ASIST)/Front End Data System (FEDS) – Formats S/C commands as Command Link Transmission Units (CLTUs) and forwards to the observatory via SDOGS – Receives housekeeping telemetry as Virtual Channel Data Units (VCDUs) from SDOGS, process the telemetry and archives the raw telemetry frames – Distributes telemetry to SOCs and other MOC components – Receives, validates and forwards instrument commands from SOCs to the instruments – Receives equipment status data from DDS and SDOGS through DSIM and process and archives the status data – Forwards control directives to DSIM to control DDS and SDOGS equipment – Maintains History Archive for the life of the mission

• Flight Dynamics System (FDS) – Suite of three COTS software tools • Satellite Tool Kit (STK) – Used to predict orbit events and ground station visibility • FreeFlyer – Used to generate SDO ephemeris, maneuver plans, and GS Acquisition Data • MatLab - Provides real-time attitude determination and display in the MOC and generates High Gain Antenna calibration command sequences

Georgia Tech Space Systems Engineering Conference 16 Deep Space Systems GT-SSEC.C.5 MOC Major Components (2 of 2)

• Mission Planning System (MPS) – Ingests and processes FDS products – Generates graphical timeline of orbital events and observatory activities – Creates Absolute Time Sequence (ATS) loads for coordinated activities • Such as Eclipse Operations, Orbit Maneuvers, Instrument Calibrations, etc.. – Provides Relative Time Sequence (RTS) load generation

• Integrated Trending and Plotting System (ITPS) – Archives raw engineering data of selected telemetry packets – Supports engineering and statistical analysis options – Supports automatic generation of routine products (plots and reports)

• Alert Notification System (ANS) – Facilitates MOC automation – Monitors critical Observatory and Ground System events – Pages FOT and SOC personnel in response to Alert conditions

Georgia Tech Space Systems Engineering Conference 17 Deep Space Systems GT-SSEC.C.5 Communications Network Diagram

Georgia Tech Space Systems Engineering Conference 18 Deep Space Systems GT-SSEC.C.5 Communications Network Overview

• Provides connectivity between each of the ground system elements supporting all levels of data exchange and voice communications for SDO mission operations.

• Science Data Distribution: – One Optical Carrier Level 3 (OC3) network to AIA (67 Mbps) from DDS – One Optical Carrier Level 3 (OC3) network to HMI (55 Mbps) from DDS – One T3 circuit to EVE (7 Mbps) from DDS – All science data delivery circuits have a Premium service rating. Carrier is required to restore service within 4 hours

• Housekeeping Telemetry and Command Distribution: – Four T1 circuits from MOC to/from SDOGS for S-band housekeeping telemetry and commands, two per SDOGS antenna site (restore time is <1minute) – Four fractional T1 circuits from MOC to SOCs for instrument commands and health and safety monitoring (restore time is <1minute) – One T1 circuit from MOC to/from DSIM for SDOGS and DDS systems remote monitoring and control (restore time is <1minute) – One T1 circuit from MOC to SOCs through DDS router for housekeeping telemetry

• NASA IO-Net for other miscellaneous external support and interfaces

Georgia Tech Space Systems Engineering Conference 19 Deep Space Systems GT-SSEC.C.5 Operations Automation (1 of 3)

• Monitoring for Data Presence – The ASIST T&C system includes a Data Presence monitor designed to generate an Alert Message when a telemetry VCDU has not been received for a period of 10 seconds. Loss of Data Presence is a critical alert condition which the ANS system detects and notifies the FOT. • Parameter Limit Monitoring – The ASIST T&C system includes standard database-driven high/low limit checking. This feature will be employed for all critical observatory telemetry and ground system monitor points. Out-of-limit conditions are detected by the ANS and the FOT is notified. • Monitoring of Unexpected Event Messages – The SDO flight software design includes generation of Flight Status Messages in response to specific anomaly conditions. These messages are processed by the ASIST T&C system similar to the way ground system-generated messages are handled. The ANS system will be configured to monitor for these messages and alert the FOT when detected. • Time-ordered Script/Procedure Execution – This feature is inherent in the ASIST STOL and Linux operating system. Routine activities such as transfer of tracking data from the SDOGS to the MOC and basic file management functions will be automated through a combination of STOL procedure and Linux Shell scripts.

Georgia Tech Space Systems Engineering Conference 20 Deep Space Systems GT-SSEC.C.5 Automation Operations (2 of 3)

• Monitoring of Real-time Critical Systems – Real-time critical systems including the ASIST, FEDS, SDOGS RRCP, and ANS will include the periodic generation of an “I’m Okay” message. The primary ANS system will be configured to monitor for these messages and alert the FOT when detected. • Internal Redundancy for Storage of Mission Data – All MOC and DDS file servers are implemented using level-5 RAID technology providing built-in data backup and recovery. • DDS DSIM Failover – The DDS design includes a Prime and Backup DSIM system. Each DSIM will pulse the alternate system to determine its operational status. If the Primary DSIM “I’m Okay” status is lost, the backup DSIM will take control and assume the Primary role. If the Backup DSIM “I’m Okay” status is lost, the Prime DSIM will generate a Fault Status for the Backup and report it to the MOC ASIST and ANS systems. The ANS system will be configured to monitor for DSIM Fault messages and alert the FOT when detected. • ANS Backup System Monitoring – The MOC design includes a Prime and Backup ANS system. Each ANS will pulse the alternate system to determine its operational status. If the Primary ANS “I’m Okay” status is lost, the backup ANS will take control and assume the Primary role. If the Backup ANS “I’m Okay” status is lost, the Prime ANS will alert the FOT.

Georgia Tech Space Systems Engineering Conference 21 Deep Space Systems GT-SSEC.C.5 Operations Automation (3 of 3)

• Full End-to-End Redundant S-band Strings – The SDO ground system design includes full redundancy from the SDOGS antennas through two separate T1 network connections and to the MOC ASIST/FEDS. This protects against any single-point failure in the S-band string as telemetry will continue to flow through the alternate string.

MOC

Telemetry Archive

Short Term Data Storage ASIST Packet Files ASIST ASIST 24H Data Set

Real-time Health & Real-time Real-time Health & Safety Telemetry Health & Safety Telemetry Firewall Site 1 Safety Telemetry WSC-MOC Cisco 2811 Router FEDS #1 FEDS #3 MOC-SOC Cisco 2811 Router Real-time SDO SOCs Health & Safety Real-time Health & Site 2 WSC-MOC Telemetry Safety Telemetry Cisco 2811 Router FEDS #2 FEDS #4

Short Term Data Storage Short Term Data Storage ASIST ASIST ASIST

Georgia Tech Space Systems Engineering Conference 22 Deep Space Systems GT-SSEC.C.5 Conclusion

• The SDO ground system is an evolving architecture combining a mix of legacy ground system components with several new designs addressing the specific needs of the SDO science mission. These new components include: – Dedicated dual S-band/Ka-Band antenna systems – High-speed science Data Distribution System – Dedicated large bandwidth SDO network and large data storage systems • The operations concept combines typical NASA/GSFC operations practices with new concepts as the result of the architecture. These concepts include: – Remote monitoring and control of the SDOGS and DDS – Distributed instrument operations performed by each SOC – Monitoring of continuous downlink of both Observatory Engineering and Science telemetry streams • The SDO ground system is currently in the early implementation stages • In approximately two years the implementation of the architecture will be completed and validated against the functionality of the actual observatory and external interfaces

Georgia Tech Space Systems Engineering Conference 23 Deep Space Systems GT-SSEC.C.5