Landsat Mission Operations Overview – Landsat Science Team

Doug DanielsLandsat Mission ManagerThe Aerospace Corporation

21 February 2018

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Agenda

Landsat 7 Operations Landsat 8 Operations Landsat Ground Network (LGN)

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Landsat 7 Recent & Upcoming Activities

No change in Observatory status or performance Operating ETM+ at 105% duty cycle

On 01 February 2018 Landsat 7 surpassed 100,000 orbits First scene acquired on orbit 100,000 was imaged at 13:59 GMT (Path 229, Row 56) and transmitted to ASN

during orbit 100,000 at 14:38 GMT 100,000 orbits equates to 4.44 billion km (2.76 billion miles) traveled, or nearly 15 round trips to the sun Landsat 7 has surpassed 6,866 days on orbit (18.81 years)

L7 Mission Operations Center (MOC) is relocating from GSFC Building 32 to Building 25 in order to allow Landsat Multi-Satellite Mission Operations Center (LMOC) build-out in current L7 space Equipment refresh and check-out nearly complete Physical move anticipated to occur in March & April 2018

Restore-L Servicing Mission “re-baseline” under-way; USGS working to understand strategy

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Attitude Control Subsystem

X-band System

S-band System Performance nominal

Enhanced Thematic Mapper +

BatteriesPerformance 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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Landsat 7 WRS Error and MLT

L7 achieved its maximum MLT of 10:14:58 on 12 August 2017

Landsat 7 drifted outside -5km west between November 12 (DOY 314) and December 3 (DOY 337) for an excursion of about 22 days

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Landsat-7 Conjunction Summary

December 2017

January 2018

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Landsat 7 Delta-I Execution Result

Landsat 7 achieved maximum MLT of 10:14:58 on August 12, 2017

Anticipated end of science mission July 10, 2021

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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

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

~July 2021

Planned

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Landsat 8 Recent & Upcoming Activities

L8 FOT successfully performed a “retro-burn” on 12 December 2017, to arrest L8’s westward ground track drift Event was a first for Landsat 8 operations and executed entirely as expected

L8 spacecraft experienced a frozen command retransmit lock flag on Thursday, 11 January 2018 FOT manually reset the command retransmit flag, and the spacecraft was returned to normal operations within a few hours During a TDRS proficiency blind acquisition, the FOT sent a NOOP command to verify an active command path Because of the slow data rate for TDRS, the NOOP command arrived just after on-board automation issued a previously

scheduled command via RTS As a result, the CCSDS command frame sequence number for the NOOP was a mismatch with what the spacecraft

expected (e.g. a classic command collision scenario) By design the spacecraft shut down the normal command pathway in order to protect itself from unauthorized commands

Happy 5th Birthday – 11 February 2018

Actively supporting Landsat 9 Landsat Multi-Satellite Mission Operations Center (LMOC) development

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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 SystemS-band System

Batteries

Solid State Recorder – File Delete (ghost file) errorsSuccessfully corrected in September 2015

Solar array

4+ plus years of on-orbit operations

October 2014 - Side-A SSM EncoderSeptember 2015 – Encoder Side-B current fluctuationsJanuary 2016 – Alternative Operations Concept B-Side

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Coarse Sun Sensor Anomaly Review Board

On-going analysis indicates observed Coarse Sun Sensor (CSS) noise “feature” may be the result of foreign object debris (FOD) within the SADA slip rings Not an emergent issue

Landsat Mission Operations Project (LMOP) chartered an Anomaly Review Board (ARB) to address observed current dropouts in Landsat 8 (L8) Coarse Sun Sensors (CSS), to include potential solar array thermal sensor variations Purpose:

• Investigate and assess root cause of Landsat 8 CSS current dropouts and thermal sensor variations• Determine corrective action alternatives (if any)

ARB includes representation from USGS and NASA Landsat 9 (L9) Projects to allow for L9 assessment of potential impacts or risks to L9 spacecraft or test approach(s)

Similar characteristics observed on Fermi where all solar array mounted CSSs experienced current drop-outs

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2018/036 - 1 day plot – CSS 9 & CSS 12 currents

♦ Typical day with drop outs shown on the left

♦ Have not found any correlation between frequency of drop outs to spacecraft activity

♦ Nominal CSS 9 & 12 currents shown below for reference

CSS 12

CSS 9

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Passive Damper Mechanism (PDM) (Temperature over life of mission)

PDM 1 Temp

PDM 2 Temp

♦ Recent PDM 1 & 2 temperatures are exhibiting an out of family increase

♦ Max temperature (>27ºC) increasing as well as minimum (>20ºC)

♦ Yellow limit is 30°C

♦ Current high temp at 27.14°C

♦ Potential correlation to CSS current drop-out under assessment

SADA Temp

Yellow limit at 30° C

PDM 2 Temp

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ARB Next Steps

OA and FOT investigate and assess root cause of Landsat 8 CSS current dropouts and thermal sensor variations

Determine corrective action alternatives (if any)

Follow-up full ARB sessions to determine appropriate course of action (if any)

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550600650700750

Total Scenes Per Day

Landsat 8 SSR & X-Band Downlink Utilization

LGN averaging 15% margin

Routinely hits 100% use

SSR memory allocation

typically <20%

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Landsat Ground Network (LGN) Status

All LGN stations performing above 98%

L7 LGN: LGS (Sioux Falls, SD) NP3 & NP4 (North Pole, AK) NSN (Neustrelitz, Germany) ASN (Alice Springs, Australia) SG1 (Svalbard, Norway)

L8 LGN: LGS (Sioux Falls, SD) GLC (Gilmore Creek, AK) NSN (Neustrelitz, Germany) ASN (Alice Springs, Australia) SGS (Svalbard, Norway)

Acronyms

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Acronym DescriptionACCA Automated Cloud Cover AssessmentACS Attitude Control SystemAPMC Agency Program Management CouncilASM Acquisition Strategy MeetingBATC Ball Aerospace and Technologies CorpbMOC Backup Mission Operations CenterCAPE Collection Activity Planning ElementCCB Configuration Control BoardCDR Critical Design ReviewCDRL Contract Data Requirements ListCHS Cloud Hosting ServicesCMC Center Management CouncilCOMSEC Communicatiions SecurityDLT Digital Linear TapeDO Delivery OrderDOORS Dynamic Object-Oriented Requirements SystemDRC Design Reference CaseEDU Engineering Development UnitEPR Engineering Peer ReviewESD Earth Science DivisionESTO Earth Science Technology OfficeETC Estimate to CompleteETM+ Enhanced Thematic Mapper PlusFOT Flight Operations TeamFPE Focal Plane ElectronicsFPM Focal Plane ModuleFTP File Transfer Protocol

Acronym DescriptionFY Fiscal YearGCP Ground Control PointGS Ground SystemGSIRD Ground System Interface Requirements DocumentGSRD Ground System Requirements DocumentGSRR Ground System Requirements ReviewGSRT Goddard System Review TeamHPA High Power Amplifier (S-Band Uplink)IC International CooperatorICD Interface Control DocumentIGE Independent Government EstimateKDP Key Decision PointLCMAP Land Change Monitoring, Assessment, and ProjectionLGAC Landsat Global Archive ConsolidationLGN Landsat Ground NetworkLMO Landsat Mission OperationsLMOC Landsat Multi-satellite Operations Center LP DAAC Land Processes Distributed Active Archive CenterLSDS Land Satellite Data SystemsMDM Mission Data ManagementMDR Mission Definition ReviewMLT Mean Local Time (Equatorial Crossing)MOC Mission Operations CenterOAG Office of Acquisitions and GrantsOLI Operational Land ImagerOps Con Operations ConceptPDB Program Decision Board

Acronym DescriptionPDR Preliminary Design ReviewPEP Performance Evaluation PlanPSM Procurement Strategy MeetingRFI Request For InformationRFO Request For OfferRFP Request for ProposalROM Rough Order of MagnitudeRWA Reaction Wheel AssemblyS/C SpacecraftSE Systems EngineeringSEMP Systems Engineering Management PlanSLI Sustainable Land ImaginingSLI-T Sustainable Land Imagining - TechnologySMD Science Mission DirectorateSN Space NetworkSOW Statement of WorkSRB Standing Review BoardSRD Spacecraft Requirements DocumentSRR System Requirements ReviewSSM Scene Select MirrorSSP Source Selection PlanSSR Solid State RecorderTIM Technical Interchange MeetingTIRS Thermal Infrared SensorTO Task OrderTRR Test Readiness ReviewUDO Undelivered Order