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Landsat Operations Overview
Landsat Science Team (LST) Meeting Sioux Falls, SD
Douglas Daniels
Landsat Mission Manager
The Aerospace Corporation
July 11, 2017
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Agenda
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Landsat Mission Operations Overview
Landsat 7 Observatory
Observatory Status
End of Mission Update
Restore-L
Landsat 8 Observatory
Observatory Status
Landsat Ground Network Evolution
International Cooperator Network
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Landsat Mission Status
Landsat 7 Acquiring at a rate of ~470 scenes per day with continental acquisition strategy
• 105% duty cycle operations for ETM+ performing smoothly
• Data acquisition in support of Northern Hemisphere growing season imaging, along with increased acquisitions over the African Continent and Central America
On-orbit performance of Landsat 7 observatory continues to be outstanding • No spacecraft or instrument anomalies since October 2014
Finalized end of mission planning – plan to overlap with Landsat 9 launch readiness
Extended mission life potential to as late as July 2021
MOC Equipment refresh underway to support extended mission operations
Landsat 8 Acquiring at a rate of ~740 scenes per day with continental acquisition strategy
On-orbit performance of Landsat 8 observatory continues to be outstanding; • No spacecraft or instrument anomalies since September 2015
• Mission data management highly effective - on-board recorder averaging 70% margin
• Achieved milestone of 1 billion kilometers traveled in May 2017
Landsat 8 Ground Network (LGN) robust – system averaging greater than 25% margin
TIRS Scene Select Mirror (SSM) Encoder Circuit B-side alternative operations concept performing very well
Currently 5 LGN stations and 18 certified IC stations • LGS (USGS), GLC (NOAA), NSN (DLR), ASN (GA), and SGS (KSAT)
MOC march to steady state operations nearly complete – targeting CY2017 Q3
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Attitude Control Subsystem
X-band System
S-band System Performance nominal
Enhanced Thematic Mapper +
Batteries Performance nominal
Solid State Recorder
Reaction Control System
•1/07/04 Fuel line #4 thermostat #1a failure
•2/24/05 Fuel line #4 thermostat failure;
Primary heater circuit disabled
•4/25/13 Fuel line #2 thermostat failure;
Redundant heater circuit disabled
Solar Array •5/14/2002 Circuit #14 Failure
•5/16/2005 Circuit # 6 Failure
•8/13/2008 Circuit #14 partial recovery
•14 circuits remain operating
•no impact to ops
•11/15/1999 SSR PWA #23 Loss
•02/11/2001 SSR PWA #12 Loss
•12/07/2005 SSR PWA #02 Loss
•08/02/2006 SSR PWA #13 Loss
•03/28/2008 SSR PWA #22 Loss
•09/03/2008 SSR PWA #23 Recovered
•10/12/2013 SSR PWA #11 Loss
•Each PWA is 4% loss of launch capacity
•Boards are likely recoverable
Performance nominal
•05/05/2004 Gyro 3 Shut Off
•1-gyro control system in
development
18+ plus years of on-orbit operations
•5/31/2003 SLC Failure
•4/01/2007 Bumper mode
Remote Tlm Cmd (RTC) Box •09/27/2014 RTC A Failover
Electrical Power Subsystem
Power Control Unit • 10/18/2014 BVR failover
Command and Data Handling
Subsystem
RF Comm Subsystem
Landsat 7 Observatory Status – No Change
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L7 WRS Error and MLT
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Landsat 7 Delta-I Execution Predicted Result
Delta-I predict revised up to
maximum MLT at 10:14:58
on August 11, 2017
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Criteria
Landsat 7 Operational mission will be declared over at the discretion of USGS, and
may be triggered by any of the following reasons:
Insufficient fuel to maintain inclination required for science mission operations
• The orbital Mean Local Time (MLT) drops below 9:15 AM
• Note: Drag Make-Up (DMU) and Risk Mitigation Maneuvers (RMM) activities use minimal amounts of fuel (fractions of a
kilogram)
Observatory becomes unable, for any reason, to produce useable science data
• Due to mission ending failures within either the spacecraft or ETM+
Key Observatory subsystems demonstrate signs of imminent failure which could result in loss of
mission
• Attitude control, propulsion, command & data handling, electrical power
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Failure Triggers for Decommissioning
The following failure scenarios precipitate an end to the science mission and the
need to decommission Landsat 7, regardless of remaining fuel or inclination (MLT
crossing)
Spacecraft component failure
• Loss of additional gyro: Single-gyro operations doesn’t support science mission operations
• Redundant BVR failure: Results in catastrophic and nearly immediate or immediate failure of ability to command and
control Landsat 7 as loss of power to spacecraft would be imminent or immediate *
• Redundant RTC failure: Command router failure results in loss of command capability for major observatory
components *
Payload component failure
• ETM+ failure: End of science mission
* In the event any of these failure scenarios would come to pass, Landsat 7
decommissioning will commence as soon as possible upon direction of the FSM
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Baseline Landsat 7 End of Mission Timeline
Nominal activities include
Exit the constellation • Lower orbit by 4km and circularize
Achieve disposal orbit • Lower orbit additional 4km (total 8km lowering) to 697km
• Burn fuel reserve at perigee to produce elliptical orbit that maximizes atmospheric drag
Passivate on-board energy sources
Eventual re-entry
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Baseline L7 End of
Mission Timeline
2021 L7
Constellation
ExitMove L7 to
Disposal OrbitLandsat 9
Launch
2020 ~Circa 2111
L7 End-of-Mission
based on MLT
Threshold
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Landsat 7 and Restore L
USGS is working with NASA on technology
demonstration
Landsat 7 is principle client for NASA Restore L
The Landsat 7 End-of-Mission Plan was recently
developed with key points that dovetail into
Restore-L mission timeline
Restore L Mission Objectives
Launch Restore L Servicing Vehicle (RSV)
RSV approach Landsat 7 and perform inspection using on-
board cameras
RSV capture and secure Landsat 7 to create combined
“stack”
Transfer between 10-110 kg of fuel from RSV to Landsat 7
Relocate combined stack to new orbit
Release Landsat 7 and retreat to safe orbit
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Landsat 7 Notional Servicing Timeline
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End of Mission will occur between Oct 2020 and Jul 2021 Launch of Landsat 9
Mean local time reaches 9:15 AM
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Landsat 8 Observatory Status – No Change
Operational Land Imager
Thermal Infrared Sensor
Propulsion Subsystem
Thermal Control System
Electrical Power System
Attitude Control System
RF Communications
Command & Data Handling System
X-band System
S-band System
Batteries
Solid State Recorder – File Delete (ghost file) errors
Successfully corrected in September 2015
Solar array
4+ plus years of on-orbit operations
October 2014 - Side-A SSM Encoder
September 2015 – Encoder Side-B current fluctuations
January 2016 – Alternative Operations Concept B-Side
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Landsat 8 On-Orbit Performance
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Completed approximately 4+ years of on-orbit science operations
Landsat 8 acquiring “all land” averaging over 740 WRS-2 scenes collected per day
Total of over 1,000,000 OLI & TIRS scenes collected as of June 2017
Observatory performance
Excellent overall spacecraft and instrument performance
Operational Land Imager (OLI) outperforming all performance requirements
Thermal Infrared Sensor (TIRS) experienced two on-orbit anomalies
• Stray light issue affecting imagery; calibration approaches are in work, but only expect to bring one of the two spectral
bands within specifications
• Scene Select Mirror (SSM) encoder experienced current increase in Oct 2014; switched to redundant circuitry and
executing alternative ops con to maximize encoder life
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OA52 through OA62 DMU: 8 RMM: 1 INC: 2
RMM6 (DOY 115) 04/24/2016 21:24
Landsat-8 WRS-2 Error (1 year)
INC4 (DOY 123) 5/2/2016 20:34
INC5 (DOY 122) 4/27/2017 14:47
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MLT = 10:11:41 a.m. as of Apr 30, 2017
Landsat-8 MLT (1 year)
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Coarse Sun Sensor (CSS) current spikes observed routinely – particularly for CSS-12
* NOTE: 20 spikes is considered the MAXIMUM count for any particular day. The actual count may be MUCH higher than 20
*
CSS Current Spikes
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Reaction Wheel 4 (RW4) Thermal Control
RW4 A-side heater has been exhibiting erratic heater cycling Cycle counts are still well within specification
• ~342,600+ total cycles to date – rated to 1 million plus
Concern that "erratic" behavior usually equates to "bad“
At no point has the B-side heater activated
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TIRS B-encoder Activity 2016 & 2017
TIRS operations concept developed following run-away current observed in the Encoder Electronics (Scene Select Mirror mechanism) Operations successfully moderates scene select mirror current
TIRS considered “GREEN”
Five most recent TIRS LUNAR Plus Calibrations compared below
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Evolution of Landsat 8 LGN Operations
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Launch through October 2016 Landsat 8 LGN Stations included: LGS (Sioux Falls), SGS (Svalbard), GLC (Fairbanks)
Average scene acquisition rate consistently approximately 725 scenes per day
Beginning in November 2016, Landsat 8 LGN Operations moved to a five station baseline in order to provide enhanced resiliency and long-term cost savings: LGS (Sioux Falls), SGS (Svalbard), GLC (Fairbanks), ASN (Alice Springs), NSN
(Neustrelitz) • Added ASN and NSN
Number of contacts at GLC and SGS were reduced
Average scene acquisition rate remains consistently approximately 725 scenes per day
I&T activities for ASN and NSN occurred between May and September 2016 with the Operational Readiness Review (ORR) being held in November Landsat 8 LGN requirements provided and implemented by the stations (with LMOP
support)
Implementation verified by LMOP (GNE staff and FOT)
Current Passes per Day Allocation
LGS GLC SGS ASN NSN
5-6 1 1 3-4 4-5
Previous Passes per
Day Allocation
LGS GLC SGS
5-6 4-6 2-4
Landsat 8 Operational LGN Configuration
GLC – Gilmore Creek, AK
LGS – EROS, Sioux Falls, SD
SGS – Svalbard, Norway
ASN – Alice Springs, Australia
NSN – Neustrelitz, Germany
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International Cooperator Ground Stations
11 Active L7 Stations 22 Active L8 Stations
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Acronyms
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Acronym Description
ACCA Automated Cloud Cover Assessment
ACS Attitude Control System
APMC Agency Program Management Council
ASM Acquisition Strategy Meeting
BATC Ball Aerospace and Technologies Corp
bMOC Backup Mission Operations Center
CAPE Collection Activity Planning Element
CCB Configuration Control Board
CDR Critical Design Review
CDRL Contract Data Requirements List
CHS Cloud Hosting Services
CMC Center Management Council
COMSEC Communicatiions Security
DLT Digital Linear Tape
DO Delivery Order
DOORS Dynamic Object-Oriented Requirements System
DRC Design Reference Case
EDU Engineering Development Unit
EPR Engineering Peer Review
ESD Earth Science Division
ESTO Earth Science Technology Office
ETC Estimate to Complete
ETM+ Enhanced Thematic Mapper Plus
FOT Flight Operations Team
FPE Focal Plane Electronics
FPM Focal Plane Module
FTP File Transfer Protocol
Acronym Description
FY Fiscal Year
GCP Ground Control Point
GS Ground System
GSIRD Ground System Interface Requirements Document
GSRD Ground System Requirements Document
GSRR Ground System Requirements Review
GSRT Goddard System Review Team
HPA High Power Amplifier (S-Band Uplink)
IC International Cooperator
ICD Interface Control Document
IGE Independent Government Estimate
KDP Key Decision Point
LCMAP Land Change Monitoring, Assessment, and Projection
LGAC Landsat Global Archive Consolidation
LGN Landsat Ground Network
LMO Landsat Mission Operations
LMOC Landsat Multi-satellite Operations Center
LP DAAC Land Processes Distributed Active Archive Center
LSDS Land Satellite Data Systems
MDM Mission Data Management
MDR Mission Definition Review
MLT Mean Local Time (Equatorial Crossing)
MOC Mission Operations Center
OAG Office of Acquisitions and Grants
OLI Operational Land Imager
Ops Con Operations Concept
PDB Program Decision Board
Acronym Description
PDR Preliminary Design Review
PEP Performance Evaluation Plan
PSM Procurement Strategy Meeting
RFI Request For Information
RFO Request For Offer
RFP Request for Proposal
ROM Rough Order of Magnitude
RWA Reaction Wheel Assembly
S/C Spacecraft
SE Systems Engineering
SEMP Systems Engineering Management Plan
SLI Sustainable Land Imagining
SLI-T Sustainable Land Imagining - Technology
SMD Science Mission Directorate
SN Space Network
SOW Statement of Work
SRB Standing Review Board
SRD Spacecraft Requirements Document
SRR System Requirements Review
SSM Scene Select Mirror
SSP Source Selection Plan
SSR Solid State Recorder
TIM Technical Interchange Meeting
TIRS Thermal Infrared Sensor
TO Task Order
TRR Test Readiness Review
UDO Undelivered Order