Laser Communica.ons Downlink and Crosslink Designs for...

LaserCommunica.onsDownlinkandCrosslinkDesignsforCubesats

EmilyClementsCalPolyCubeSatWorkshop2016

PI:Prof.KerriCahoy

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•  TheNeedforCubeSatLasercom-  Mo6va6on-  Keydesigntrades

•  ApproachandEnablingTechnologies•  OngoingMITPrograms:-  NanosatelliteOp6calDownlinkExperiment(NODE)-  FreespaceLasercomAndRadia6onExperiment(FLARE)-  KitCube

•  TheFutureofCubeSatLasercom

Outline

TheneedforCL Approach/EnablingTech OngoingPrograms FutureofCL

TheNeedforCubeSatLasercom•  Transi6oningtomoreadvancedpayloadsrequireshigherdatarates

thanUHFwithtapespringantennacanprovide[4]•  Transmitpowerandcost/accessibilityofhigh-gaingroundsta6onsare

usuallythelimi6ngfactorsinCubeSatRFdatarate[5]

•  Lasercommunica6onismorepower-efficientthanRF:–  ChannelcapacityCscaleswithwavelengthλ:

à  LasercomisanaIrac.vesolu.onforfutureprograms

•  Ongoingcompactlasercomwork:AerospaceOCSD[15],Facebook[16],DLR[17],BridgeSat/Surrey,RUAG,MITprograms,&others–  Relatedtechnology:CHOMPTT[20]

3

COpt.

CRF

∝λRFλopt.

⎛

⎝⎜⎜

⎞

⎠⎟⎟

2


CommforAdvancedLEOCubeSats

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•  Figureassumespayloadsarerunningcon6nuously&downlinkisnotlimitedbynumberordura6onofpasses

•  High-power,high-datapayloadsdriveneedforCubeSatLasercom

Orbitalpowerusage[Wh]

30

20

100

~13Wh/orbitgeneratedby3UCubeSatwithdeployablesolarpanels[11]

0.2MB/orbitMagnetometer[6]

200MB/orbit3Mpcamera[8]

28,000MB/orbitLow-resolu6onvideo[4,10]

7500MB/orbitHyperspectral[9]

PayloadPower3MbpsUHFConsumedPower[12]5MbpsSBandConsumedPower[13]100MbpsXBandConsumedPower[14]50MbpsLasercomConsumedPower(NODEwith1mgroundsta6on)

~26Wh/orbitgeneratedby6UCubeSatwithdeployablesolarpanels

Clements2016


LasercomPoin6ngChallenges

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NODE

FLAREKitCube

•  Keychallenge:poin.ngcontrol-  Lasercombeamwidthstestlimits

ofCubeSataetudecontrolwithEarthHorizonSensors(EHS)&SunSensors(SS)

•  Wewilldiscusssolu6onsMIT

CubeSatlasercomprograms:-  NODE:LEOdownlink[2]-  FLARE:CrosslinksinLEO-  KitCube:Downlinkfromlunar

orbit[18]

LasercomPower&BeamwidthTrade

Startrackerreq’d

EHS+SS

Clements2016

Beamwidth(milliradians)

Transm

itPo

wer(W

)


COTSforCubeSatLasercom

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Spaceterminalpoin.ngcontrolenabledbyCOTSFastSteeringMirror(FSM)Credit:KathleenRiesing

Seed$Laser$+$ER$Filter$FPGA$ EDFA$

FPGA$Electrical$Output$ EDFA$Filtered$Op8cal$Input$ EDFA$Op8cal$Output$PPM<16$

5$ns$pulse$$

+23$dBm$

ER>33dB$High$fidelity$waveform$ASE<0.2$dB$

<7$dBm$

TransmiIerelectronicsleveragestelecomtechnologyCredit:RyanKingsbury[2]

MITGroundsta.onusesAmateurTelescopeandlaptop

Credit:HyosangYoon

SelectedCOTStecharchitecturewithamplifica.onusingEDFAtoenablelowcost(<$20kinpartscost)systemscalableto100Mbps


Uncertainty-basedLinkAnalysisDevelopingnewlinkanalysisapproachtohandlesystemuncertain.es:•  COTSpartsnotyetqualifiedforspaceenvironment•  Tradi6onal,worst-caselinkanalysisistooconserva6veforrisk-tolerantCubeSats•  Probabilis6cmodelingapproachtolasercomlinkbudgetshelpstoassessrisks

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Clements2016


Uncertainty-basedLinkAnalysis

à  Howtoaddressuncertain.es:Useglobalsensi6vityanalysistoiden6fyuncertain6eswithhighestimpactonLinkMargin•  Globalsensi6vityanalysishelpstovisualizecontributorstoperformanceuncertainty

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Clements2016

SobolSensi6vi6es


NODEOverview

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Receiver-  OCTLandAmateurtelescope-  Detector:COTSavalanche

photodiode-  Poin6ngandtracking:COTS

infraredcamera+startracker

TransmiIer-  Electronics:Commercialtelecomlaser

components,PPMmodula6on-  Mechanical:3Dprintedstructure-  Poin6ngstrategy:buspoin6ng(coarsepoin6ng),

Faststeeringmirror(finepoin6ng)-  Componentsintwosubmodules

TransmikerEDFAsubmodule

Transmikerop6cssubmodule

120mm

•  NanosatelliteOp6calDownlinkExperiment•  10-100MbpsdownlinkfromLEOCubeSatw/1550nm,2.26mradbeam•  <10Wconsumedpowerfor0.2Wtransmitpower•  LeveragesCOTSpartsfortransmikerandreceiver

Credit:HyosangYoonCADCredit:DerekBarnes


NODEI&TProgressUpdate

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FSM&TransmiIerPrototyping

MechanicalPrototyping GroundSta.onPrototyping

Func.onalTes.ng

PhotoCredit:ClementsGSlead:HyosangYoon

Photocredit:ClementsPrototyping:Aniceto,Barnes,Clark,Haughwout

Photocredits:ClementsPrototyping:Clark,Haughwout

Photocredit:ClementsPrototyping:Ziegler,Lee


FreespaceLasercomandRadia6onExperiment•  Intersatellitelasercommunica6onswithCubeSats•  Twosatellites,compacthalf-duplextransceiversystem•  MIT’sentryintotheAFRLUNP-9compe66on•  Pre-PDR

FLAREMissionOverview

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CADCredit:MaximKhatsenko

Lasercomtransmitaperture(2.26mradbeam) 8.5cmlasercom

receiveaperture

ADCSprovides3axisaetudecontrol

Powermanagement&bakeries

Sparrow[19]module(SecondaryPayload)

Sparrowwindow(SecondaryPayload)

4thrustersmaintainsatellitecrosslink

distance

FuelTank

EDFAoutputs1550nm1.2Wlasersignal

BusFPGAgeneratessignalforlasercomseedlaser&interpretsreceivedsignals


ProgramObjec.ves•  MIT’sentryintotheNASACubeQuestChallenge•  Designandbuilda6UCubeSatthatwinsoneofthe3remainingspotsonSLSEM-1.•  Achievelunarorbit($1.5M)•  GoalofwinningtheBestBurstDataRatecompe66onwithalasercommunica6ons

downlinktransmiker.•  Alsocompeteforlargestaggregatedatavolume,andlongevity.

KitCubeMissionOverview

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Lasercompayload:•  1550nm1.2Wtransmiker•  0.1mradbeam•  BeaconreceiverPoin6ngsolu6ons:

•  Reac6onwheels•  Twostartrackers

CADCredit:MaximKhatsenko


TheFutureofCubeSatLasercom

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LEOdownlinkMITexample:NODE>50Mbpswith0.2Wtransmiker&1mgroundsta6onOtherexamples:AerospaceOCSD,CHOMPTT

LEOdownlink½Upayload&groundsta6onnetworkwouldenablehigherdutycyclesofadvancedCubeSatpayloads

LEOcrosslinkMITexample:FLARE>10Mbpswith1.2Wtransmiker

LEOcrosslinkLow-powercrosslinksreducelatencyofdownlinkingpayloaddata

UpcomingTechDemoMissions(MITexamples;manyothersexist)

FutureArchitectures

LunardownlinkMITexample:KitCube>1Mbpswith1.2Wtransmiker

DeepspaceCubeSatscouldbeusedasprobesoninterplanetarymissions(ex.Starshot),withthecommunica6onabilitytorelayfindingsbacktoEarth

AcknowledgementsStudents(pastandpresent)GraduateStudentsInigodelPor6lloBarriosKateCantuAshleyCarltonJimClarkEmilyClementsAngieCrewsKarlGantnerChris6anHaughwoutAyeshaHeinKitKennedyMaximKhatsenkoRyanKingsburyCharlokeLoweyMyronLeeZachLeeWestonMarlowKatRiesingArmenSamurkashianDivyaShankarHyosangYoonCalebZiegler

UndergraduateStudentsRaichelleAnicetoDerekBarnesScarlekKollerBjarniKris6nssonRachelMorganMayaNasrJohannesNorheimElishevaShuterRachelWeinbergHighSchoolStudentsBradenOh+ProjectSeleneteamAdvisorsProfessorsKerriCahoy

MentorsJamieBurnsideDaveCaplan(MITLL)BillFarr(NASAJPL)ZachHartwig(MITPost-doc)JeffMendenhall(MITLL)JonathanTwichell(MITLL)

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References1.  Swartwout,Michael."Thefirstonehundredcubesats:Asta6s6callook."JournalofSmallSatellites2.2(2013):213-233.2.  Kingsbury,R.W.,D.O.Caplan,andK.L.Cahoy."Compactop6caltransmikersforCubeSatfree-spaceop6calcommunica6ons."SPIE

LASE.Interna6onalSocietyforOp6csandPhotonics,2015.3.  hkp://www.klofas.com/comm-table/table.pdf4.  Selva,Daniel,andDavidKrejci."Asurveyandassessmentofthecapabili6esofCubesatsforEarthobserva6on."ActaAstronau6ca74

(2012):50-68.5.  Bouwmeester,Jasper,andJ.Guo."Surveyofworldwidepico-andnanosatellitemissions,distribu6onsandsubsystemtechnology."

ActaAstronau6ca67.7(2010):854-862.6.  Long,Makhew,etal."Acubesatderiveddesignforauniqueacademicresearchmissioninearthquakesignaturedetec6on."Proc.

AIAASmallSatelliteConference.2002.7.  AnneMarinan,PersonalCommunica6on8.  hkp://www.cubesatshop.com/index.php?

page=shop.product_details&flypage=flypage.tpl&product_id=63&category_id=16&op6on=com_virtuemart&Itemid=809.  hkp://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150023589.pdf10.  hkp://cdn2.hubspot.net/hubfs/145999/docs/VNIR.pdf?t=145986198180711.  Blackwell,William,etal."MicroMAS:AFirstStepTowardsaNanosatelliteConstella6onforGlobalStormObserva6on."(2013).12.  Marinan,AnneDorothy.FromCubeSatstoconstella6ons:systemsdesignandperformanceanalysis.Diss.MassachuseksIns6tuteof

Technology,2013.13.  hkp://www.tethers.com/SpecSheets/Brochure_SWIFT_SLX.pdf14.  hkp://www.tethers.com/SpecSheets/Brochure_SWIFT_XTS_SFN.pdf15.  Welle,RichardP."CUBESAT-SCALELASERCOMMUNICATIONS."(2015).16.  hkp://www.wired.com/2016/01/facebook-zuckerberg-internet-org/17.  Schmidt,Christopher,etal."OSIRISpayloadforDLR’sBiROSsatellite."Proc.ofInterna6onalConferenceonSpaceOp6calSystems

andApplica6ons(ICSOS),Kobe,Japan.2014.18.  hkps://crowdfund.mit.edu/project/150119.  Chris6anHaughwout,ZachHartwig,AshleyCarlton,andKerriCahoy.“MiniaturePar6cleDiscrimina6ngRadia6onSensors:

TechnologyDevelopmentandDemonstra6onona1UCubeSat”.PosteratCubesatCommunitySymposium,September2015,IrvineCA

20.  Barnwell,Nathan,etal."CubeSatHandlingofMul6systemPrecisionTimeTransfer."(2015).

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BackupSlides

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PPM Diagrams

Credit:RyanKingsbury

Credit:LaserCommunicaFonTransmiHerandReceiverDesignbyDaveCaplan

Abstract"LaserCommunica6onsDownlinkandCrosslinkDesignsforCubeSats”Op6calcommunica6on,orlasercom,canprovidemuchhigherlinkratesthananRFsystemwithcomparableenergyconsump6on.Thisisbecauseop6calsignalscanbedirectedmoreeffec6velytowardsthegroundsta6on.Themainengineeringcostsassociatedwiththesesystemsarethestringentpoin6ngrequirementsthatareleviedonthelasertransmiker.RecentadvancesinCubeSataetudedetermina6onandcontrolsystems(ADCS)areaddressingtheseneeds,andtherehavebeenseveralmissionsthathavedemonstratedthree-axisstabiliza6on–akeyenablerforlasercom.Wediscussdevelopmentsinlasercommunica6onscapabili6esfordownlinkandcrosslinkon3Uand6Unanosatellitepla�ormsandgroundsta6onsbasedlargelyoncommerciallyavailablecomponents.Wepresentpredictedandprototypedcapabili6esofspacecra�transmikersandreceiversforapower-constrained1550nmdirect-detec6onsystemwithaverageoutputpowerrangingfrom200mWto1.2Wforthreecasestudies:low-Earthorbitdownlink,low-Earthorbitcrosslink,anddeepspacedownlink.Wedescribeexpectedperformanceforarepresenta6veorbitalconfigura6ons,includingconsidera6onofpropulsionandpoin6ngcapability,aswellasgroundsta6ongeometriesforthesecasestudies.Passiveandac6vebeaconapproachesarealsoconsidered.ThecasestudiescaptureongoingworkatMITontheNanosatelliteOp6calDownlinkExperiment(NODE),theMITKitCubeentryintheNASACubeQuestLunarDerbyChallenge,andtheFree-spaceLasercomandRadia6onExperiment(FLARE)intheUniversityNanosatelliteProgram9.Lasercomhasthepoten6altounlocklargeamountsofbandwidthatop6calwavelengthsevenforresource-constrainedCubeSatpla�orms.Thehighlydirectednatureoftheop6callinksmakethemextremelydifficulttointerceptandjamresistant.Thesesamelinkparametersalsosupportextensivespa6alreuseofcarrierfrequencies.Weuseonboardmemorystoragetoaddressweather/availabilityconcernsforusingop6caltransceiversforgrounduplinkanddownlink.Manymissionsdonothave“real-6me”downlinklatencyrequirements,sodatacanbestoredonboardun6lagroundsta6onisavailable.Applica6onswithmorestringentlatencyrequirementscanfieldaddi6onalgeographicallydiversegroundsta6ons,par6cularlyifthegroundsta6onsarecompactandlow-cost.

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Laser Communica.ons Downlink and Crosslink Designs for...

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