Section 19.0Combined Ground System
Irene BibykGround System Manager
ST5 PDR June 19-20, 2001
GSFC5Space Technology
“Tomorrow’s Technology Today”
ST5 PDR June 19-20, 2001
GSFC
19-2
•Introduction•Mission Operation Center Integration•Ground Data System - ASIST•Ground Station/Network
– Flight Dynamics
•ST5 Technology Demonstration - SatTrack•Risk Mitigation
Agenda
Introduction
ST5 PDR June 19-20, 2001
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“Tomorrow’s Technology Today”
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ST5 PDR June 19-20, 2001
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Combined Ground System & Operations
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FOP
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Documentation• Operations Concept Document - Preliminary complete
– Flight Operations Plan
– Flight Procedures Document
– Launch & Early Orbit Handbook
• Detailed Mission Requirements Document - Preliminary complete– ASIST ICD - Heritage from MAP & EO-1
– FD ICD
• SatTrack Requirements Document - Complete– SatTrack Statement of Work - Complete
– SatTrack ICD
• Ground Station Requirements Document - Complete– Ground Station Statement of Work - Preliminary complete
– Ground Station RF ICD
ST5 PDR June 19-20, 2001
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Major MilestonesFY01 FY02 FY03
Date Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Milestone Ap Ma Jun Jul Au Se Oc No De Ja Fe Ma Ap Ma Jun Jul Au Se Oc No De Ja Fe Ma Ap Ma Jun Jul Au Se
ASIST / FEDSW/Ss FSW HDS C&DH FlatSat s/c1 s/c2&3FEDS C&DH FSWFlatSat s/c1 s/c2&3
MOC Int & MRTMRT1 (FlatSat Tests)SIM#1First Test w/MOCMRT2 (S/C 1 Test)SIM#2 (S/C 1 Env)GroundSeg TestsMRT3 (Constellation Test)SIM#3 (S/C 2 & 3 Env)MRR (Jul'03)
Ground StationSelection (Jul'01)Peer Review -DesignGnd RF ICDAntenna Upgrades & Compat H/W DevUpgrade CertificationRF Compat TestGround Network MRT
SatTrackContract AwardS/W Del#1 (OD Tool)SatTrack (w/MRT1)S/W Del#2 (Auto Sched Tool)SatTrack MRT
Mission Operation Center Integration
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Requirements/Approach• The GDS shall provide interface support for the Autonomous
Network Scheduling and Orbit Determination S/W (MRD 30401000)– ASIST shall interface with SatTrack via a TCP/IP socket for ascii file transfer
• The mission shall be capable of supporting “lights out” operations (MRD 30500000)– Standard GSFC automation approach with ASIST and SERS, except for the
addition of the ST5 tech demo of SatTrack
• Approach– In-house mission operations center will be co-located with one of the existing
MOCs in Bldg. 14, such as MAP, TRACE or EO-1• Heritage system in an existing facility will reduce risk and save money by taking advantage
of security perimeter, redundant utilities and communications. (Note: FOT and systems are not planned to be shared)
– FOT training and control center checkout to occur during I&T
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Data Flow Diagram
ST5 Mission Operations Center
SatTrack/Tech Demo- Automated
Ground StationScheduling and
- OrbitDetermination
RTADS (L&EO)-Near RealTime AttitudeDetermination for Launch
& Early Orbit - Maneuver Planning JPL CCNT
Ground System
ST5 Experimenter Operations Center
ASIST- Telemetry Monitoring
- Command Load & Uplink- Data Storage
- Limit Checking- Events Monitor
- Automated STOL Proc Exec
NASAIntegrated Services Network
Commands/VC#
RealTime System
NISN
MMFD/Nom Ops-Bldg 28
- Orbit Predict
Magnetometer(ASIST Assoc)
Data
GroundStation
- Sun sensor- Magnetometer
- Ranging- Data transfer- Science event
Real time Data/VC#
Recorder Data/VC# - Predicted Orbit
Orbit
- Uplink/Downlink on X-Band- Two way Doppler Tracking
EARTH
- Exp Planning- Instrument Eval- Experiment Data Processing
SkytelPagingService
GPS
Offline System
Tracking
OrbitPred
Tracking
- Attitude
Telemetry
Commands
RTADS (Nominal)
GSFC-site
Attitude
VMOC DataServer
PAGE FOT
Mission PlanningSystem Planning Aids
Auto-STOL Proc/Status
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Mission Readiness Test Flow
FlatSat Test Series- Basic Timing Test-MOC Set-up Test
- Tlm & Cmd Processing Test- Tech Data Validation Test
-Cmd Management Test
Aug’02 - Oct’02
Ground Segment Test Serieswith FlatSat and/or S/C No.1
- TT&C Ground Station TestsMission Planning & Scheduling Tests
- SatTrack Lights-out TestComprehensive Ground Station Test
- Mission Science Data Processing Test
Nov’02 - Mar’03
S/C No.1Integration & Test
S/C No.1Enviromental Tests
S/C No.1 Test Series- Basic Timing Test No.2 Tech Aliveness Test No.2
- PTP Validation Test- RF Compatibility Test(Pre-TV)- Basic Timing Test No.2 (in TV)
- RF Compatibility Test (Post-TV)
S/C No.2 & No.3Integration & Test
Jan’03 - Apr’03
Constellation Test Series- RF Compatibility Tests (No.2&No.3 - Pre-TV)
- Technology Aliveness Test No.3- Comprehensive Timing Test No.3
- FINAL End - to - End Test (Cmd & Tlm Test)
May’03 - Jul’03
Three Series of Tests (FlatSat, S/C No.1, Constellation)
Simulation No.1(FlatSat)
S/C No.2 & No.3Environmental Tests
May’02 - Oct’02 Nov’02 - Mar’03
Simulation No.2S/C 1 (Env)
Apr’03 - Jun’03
Simulation No.3S/C 2 & 3 (Env)
Apr’03 - Jun’03
Aug’02 Feb’03 Jul’03
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Status•High level integrated schedule with I&T
developed•H/W and S/W purchases (ASIST/FEDS) •I&T, Ops, subsystem staffing for I&T, Mission
Readiness Tests and Mission Operations in work
Ground Data System-ASIST
ST5 PDR June 19-20, 2001
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• The Mission shall validate the ability to take measurements and to handle the downlink and ground data processing of multiple data streams from multiple S/C (MRD 20300000)– New ASIST capability where the FEDS will contain multiple ingest cards and
data streams will be sorted by S/C ID– Existing data interface protocols will be used with SERS, FD, MPSS, and new
technologies (SatTrack and CCNT)
• The facility shall have the ability to connect with the vehicle(s) at both baseband (i.e. Hard-Line) and RF (MRD10303080 - supporting)– Heritage connection where the FEDS shall have the ability to connect to the
vehicles during I&T
• CCSDS recommendations shall apply to space/ground com channels and to basic space/ground services provided to instruments by the S/C (MRD 10303050)– CCSDS applications are heritage systems
Requirements
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• Time correlation between the S/C clock & Coordinated Universal Time (UTC) shall be known to within 5 msec
(3 sigma) (MRD 20500000 - supporting)– Heritage from EO-1 for Return Data Delay (RDD) time correlation– Ground station will append the time each VC0 CADU was received at the
ground station to the internet protocol data unit (IPDU) header and the FEDS will read both S/C time and ground station time tag to determine S/C to UTC time difference
• Approach: Heritage systems from IMAGE, EO-1 and MAP; ST5 FSW re-using MAP FSW; ST5 C&DH re-using MAP processor
Requirements/Approach
ST5 PDR June 19-20, 2001
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S/C 1
S/C 2
S/C 3
S/C Data System
X-BandXponder
Data CLK
C & DH HDS
FEDS
GroundStationGnd Stat I/F
TCPIP
PCI Serial I/O
ACB2
Bit Sync
S-BandRcvr
X- to S- DownConverter
I & T GSE
TSS2000Modulator
BPSK
S- to X- UpConverter
I/F BoxDiplexer RF
Cmd ProcessorFrame
Sync (S/W)(CRC, RS)
R/TBuffer(S/W)
PacketDistribution
System
Time CodeCard
DigitalHistory
DataStorage (DHDS)
ASISTPrimary
Workstation
ASISTAssociate
Workstations S/C TestConnectio
n
I & T Only
Ops Only
I&T and Operations Command & Telemetry Flows
NISN
ASISTScience
WorkstationsCCNT
Workstations
ST5 PDR June 19-20, 2001
GSFC
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•ASIST Workstation deliveries to FSW and GNC (for HDS) completed
•FEDS (Front End Data System) in development for C&DH– Timing card will be included
•FEDS and ASIST deliveries to FlatSat and FSW in first quarter FY02
•Testing multiple ingest cards in FEDS•ASIST Build 9.1 (some updates with multiple
data streams)•Working data management and verification of
crosslink data from CCNT
Status
Ground Station/Network
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• The ground segment shall provide one 20-minute contact window per S/C every orbit below 5 Re altitude (MRD 10801000)– For nominal operations, ground stations being required to provide
30 minutes of visibility for simultaneous data command, telemetry, and tracking, • Extra time added for link acquisition and margin
– Stations must be compatible with new ST5 technology transponder; sweep, acquire and lock as listed in the ground station requirements specification
– Data recovery goal for ground station is 90% (space to ground), in support of technology and science validation requirements minimum of 70% of on-orbit generated data constellation in total shall be received by the ground (MRD 10800000 - supporting)
Requirements
ST5 PDR June 19-20, 2001
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• The ground station network shall provide X-band command uplink capability, in at least 1 station (MRD 10104041)– 2 stations are highly desirable for more coverage with orbit
uncertainties and as a back-up station– Nominal operations may be capable to work with a less-than-
once-per-orbit uplink command window (i.e., every 2nd/3rd pass)• Time correlation (update S/C clock), tracking and operational
scenarios will determine the uplink contact frequency
• The system uplink data rate shall be 1 Kbps. (MRD 10303061 - supporting)– New X-band equipment required, but data rate is not
challenging
Requirements
ST5 PDR June 19-20, 2001
GSFC
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Requirements• The S/C shall have 2, ground selectable, downlink data rates:
1 Kbps (2 Ksps) and 100 Kbps (200 Ksps) (MRD 10303063 - supporting)– The S/C shall be capable of supporting the high rate downlink to a
communications range of 5 Re. (MRD 10303065 - supporting)
– The S/C shall be able to support the low data rate downlink at any point in the orbit (MRD 10303066 - supporting)
• The ground station shall be capable of performing Doppler tracking in support of orbit determination (MRD 10301020)– The system radiometric Doppler tracking accuracy shall be sufficient to support
ground antenna pointing at distances of 2 to 5 Re. (MRD 10301011 - supporting)
• Ground station oscillator must be stable enough to support
– The system shall be capable of supporting the mission using only one-way Doppler measurements from the S/C (10301012 - supporting)
• Transponder oscillator will determine performance
ST5 PDR June 19-20, 2001
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Apogee @ ~5:15
Perigee @~10:31
2 Re @ ~9:32
2 Re@ ~0:58
5 Re@ ~3:22
5 Re @ ~7:08
Perigee @~0:00
2hrs&24mins144mins
Nominal Operations Total contact time required per orbit: ~90 mins (1.5 hrs) - Range limited between 2 - 5 Re for simultaneous:- Recorder downlink at 100 kbps (range limiting factor)- Real-time downlink at 1 kbps- Command uplink at 1 kbps- Two-way Doppler tracking
Notes (for s/c illustration):All attitude and orientations not to scaleS/C and antenna beam not to scaleS/C distances not to scale
Orbit Scenario
L&EO: No time specs, need schedule flexibilityAny Point in Orbit for simultaneous:- Real-time downlink at 1 kbps- Command uplink at 1 kbps- Two-way Doppler tracking
ST5 PDR June 19-20, 2001
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Orbit Analysis - PreliminaryAssumptions: Apogee at ascending node, perigee at descending node, Epoch December, Antenna spinning 86-40ºoff boresight, inclination of 25 º, eclipse not included
L&EO Req: Flexibility to ensure H&S C/O---->
NominalOperationsReq: 180 mins/day ---->
ST-5 Coverage Summary Table 14 Day Pass Stats (mins)
Maximum Minimum Average Min/Day Maximum Minimum Average Min/DayKiruna 584.6 111.2 293.4 398.2 0.0 0.0 0.0 0.0Fairbanks 608.7 76.6 289.5 413.5 0.0 0.0 0.0 0.0Horsham 452.6 22.1 172.6 308.1 0.0 0.0 0.0 0.0Madrid 360.8 0.1 145.8 302.0 0.0 0.0 0.0 0.0Goldstone 343.1 10.6 133.5 276.6 0.0 0.0 0.0 0.0South Florida 326.7 0.8 129.7 222.4 57.2 31.0 41.3 8.8Hawaii 300.8 0.6 104.4 164.0 174.0 26.3 105.2 52.6Canberra 0.0 0.0 0.0 0.0 525.4 0.8 203.9 407.7
Maximum Minimum Average Min/Day Maximum Minimum Average Min/DayKiruna 132.7 81.3 113.9 122.0 0.0 0.0 0.0 0.0Fairbanks 135.3 3.6 97.3 118.1 0.0 0.0 0.0 0.0Horsham 139.0 2.6 55.6 91.3 0.0 0.0 0.0 0.0Madrid 124.0 5.6 58.0 107.7 0.0 0.0 0.0 0.0Goldstone 121.0 5.4 59.9 89.8 0.0 0.0 0.0 0.0South Florida 131.0 3.6 72.2 77.3 55.1 26.6 36.3 7.8Hawaii 141.7 0.5 94.4 87.7 127.5 26.3 84.7 42.3Canberra 0.0 0.0 0.0 0.0 148.3 3.9 68.4 102.6
Antenna Pointing Ecliptic North Antenna Pointing Ecliptic SouthUnconstrained Range from Station
Antenna Pointing Ecliptic North Antenna Pointing Ecliptic South
Constrained 1-5 Re Range from Station
ST5 PDR June 19-20, 2001
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Requirements• Ground station-received AGC levels in addition to auto-
tracking antenna angles shall be provided (MRD 10104024)– Ground stations to provide data each pass in support of transponder
performance validation• Information is currently available today - no changes
• Time correlation between the S/C clock and UTC shall be known to within 5 msec (3 sigma) (MRD 20500000 - supporting)– Telemetry received by the ground network shall be time tagged to an
accuracy of at least 1 msec (3 sigma) of UTC (20504000)• With today’s GPS H/W at the ground stations, this can be accomplished easily
ST5 PDR June 19-20, 2001
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•Modify an existing station network to support ST5– Many existing stations have S-band transmitter with an X-band
receiver and the receiver is compatible with ST5 transponder
– DSN only station network with X-band transmitter and receiver (not planning to use DSN for ST5 Operations)
Approach
ST5 PDR June 19-20, 2001
GSFC
19-25
•Requirements document (ST5-495-052) completed•SOW (ST5-495-064) and Task Order in process•Preliminary visibility analysis completed•Major Milestones
– Ground station (commercial or government) on board - August 2001
– Ground Station ICD - December 2001
– RF Compatibility tests - November 2002
– MRT- Operational Readiness - May 2003
Status
Flight Dynamics
ST5 PDR June 19-20, 2001
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“Tomorrow’s Technology Today”
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ST5 PDR June 19-20, 2001
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• Pre-launch-develop and verify tracking method – Pre-launch support for 2-way Doppler tracking requirement definition and
verification
– Post launch, MMFD located in Bldg 28 (GSFC) is prime for OD support at launch and during nominal mission operations
• Orbit determination within 10 km for ground antenna pointing– An 11-m ground antenna at a distance of 2 Re from S/C, orbit position
knowledge of 24Km (3 sigma) or a deviation of no more than 8Km (1 sigma)
• Maneuver support during launch and early orbit– Attitude and orbit determination
• Attitude and orbit product generation– Products required throughout operations
Approach
Autonomous Network Scheduling and Orbit Determination S/W Requirements
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ST5 PDR June 19-20, 2001
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• Technology Provider - Bester Tracking Systems, Inc.• Technology Description
– Future Ground Operations Automation for Constellations Enabling Technology• S/W tool to perform autonomously• Ground station scheduling and orbit determination
• Experience– 1st revision to be used on HESSI
• HESSI uses GSFC’s ITOS ground system
• Technology Readiness Level => Currently: 4 (SatTrack) => Currently: 2 (New tools) => Phase D: 7
– Ground station schedule conflict resolution• Station view periods, dynamic link margin, S/C emergencies, time constrains
– Flight Dynamics Requirements• Includes comprehensive products such as orbit determination, mission planning
products, state vectors, real-time graphic & alphanumeric displays
Technology Demonstration
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• The system shall validate the Autonomous Network Scheduling and Orbit Determination S/W (MRD 10108000)– In addition to actual assets for the mission (i.e. 3 S/C and 2 ground
stations), a set of virtual assets (i.e. both S/C and ground stations) shall be simulated and supplied to the Autonomous Network Scheduling and Orbit Determination S/W for processing (MRD 10108020)
– Flight validation of the Autonomous Network Scheduling and Orbit Determination S/W shall be accomplished through comparison of the generated output with standard orbit determination S/W and manual ground resource scheduling techniques (MRD 10108010)
– Anomalous operation of the Autonomous Network Scheduling and Orbit Determination S/W shall not degrade the operation of the S/C (MRD 10108040)
Requirements
ST5 PDR June 19-20, 2001
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ST5 Mission Operations Scenario of 3 real and 97 virtual satellites
ST5 PDR June 19-20, 2001
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Ground Station(s) Multi-MissionFlight Dynamics
ASIST/FEDS
Mission Planning /Scheduling System
Mission Planning
Load Generation
Ground StationScheduling
Command Loads
Commanding
Telemetry Monitoring
Data Storage
Commands Telemetry
SatTrack
Orbit Determination
Mission Planning Product Generation
Ground Station Scheduling
Orbit Determination
Mission PlanningProduct Generation
Mission Planning Products
Automated STOLProcedure Initiation
Schedules
Tracking Data
Status feedback
Data Flow for SatTrack Validation
ST5 PDR June 19-20, 2001
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SatTrack S/W Technology•Used for efficient management and Autonomous
Operation of a Satellite Constellation– Autonomous scheduling of ground station contacts
• Calculate station access based on number of constraints (line-of-sight, geometry, link margin)
– Calculate priorities to resolve conflicts based on various input parameters• data volumes, station capability & availability, science requirements, S/C
emergencies, operator overrides, etc.
– Autonomous Orbit Determination• Derive updated state vectors from angle & range rate measurements
• Verify & archive new state vectors
• Generate mission planning products with new state vectors
ST5 PDR June 19-20, 2001
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SatTrack Status•Status
– Requirements document (ST5-495-046) completed
– SOW (ST5-495-045) completed, waiting for proposal
•Major Milestones– S/W delivery 1 (Orbit Determination Tool)-July 2002
– S/W delivery 2 (Automated Scheduling Tool)-February 2003
– Mission Readiness Test-April 2003
Risk Mitigation
ST5 PDR June 19-20, 2001
GSFC5Space Technology
“Tomorrow’s Technology Today”
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ST5 PDR June 19-20, 2001
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Risk Mitigation• Risk: No ground stations are currently compatible with ST5
transponder which lead to uncertainties with costs and schedule for upgrades– Mitigation: CSOC has identified potential vendors with a fixed-price cost estimate
• Risk: Actual launch scenario not fully defined resulting in ground system uncertainty– Mitigation: Concerned about ground station visibility to meet requirements for
L&EO, tracking, health & safety, and data recovery
– Preliminary analysis has identified visibility against typical launch scenario
• Risk: Staffing in the timeframe prior & during S/C No.2 & No.3 flow– Mitigation: Relying on subsystem personnel to supplement Mission Operations
activities
– Relying on an existing GSFC MOC facility with most interfaces for Mission Operations in place