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Swampsat Antenna System

Permanent Link: http://ufdc.ufl.edu/UFE0025042/00001

Material Information

Title: Swampsat Antenna System
Physical Description: 1 online resource (58 p.)
Language: english
Creator: Buckley, Dante
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
Genre: Aerospace Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: SwampSat, the first CubeSat mission of the University of Florida, is an on-orbit technology demonstrator of a compact three-axis attitude control system capable of rapid retargeting and precision pointing (R2P2). This thesis addresses the design and test of the SwampSat antenna system. Various antenna configurations, antenna materials, packaging and deployment techniques feasible for SwampSat operation were surveyed. Based on the survey, a dipole antenna design was adopted for SwampSat. The SwampSat antenna system consists of two modules which integrate the structural and electrical components in a non-intrusive manner. The antenna system modules are developed to support an assembly process which can be performed independently and then interfaced to the SwampSat structural frame and electrical components. A burn-wire deployment mechanism has been designed for each module. Prototypes of the antenna system have been fabricated and tested and the final flight design is presented. The antenna system will undergo further field and deployment tests to mitigate any failure modes.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Dante Buckley.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Fitz-Coy, Norman G.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-06-30

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0025042:00001

Permanent Link: http://ufdc.ufl.edu/UFE0025042/00001

Material Information

Title: Swampsat Antenna System
Physical Description: 1 online resource (58 p.)
Language: english
Creator: Buckley, Dante
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2009

Subjects

Subjects / Keywords: Mechanical and Aerospace Engineering -- Dissertations, Academic -- UF
Genre: Aerospace Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: SwampSat, the first CubeSat mission of the University of Florida, is an on-orbit technology demonstrator of a compact three-axis attitude control system capable of rapid retargeting and precision pointing (R2P2). This thesis addresses the design and test of the SwampSat antenna system. Various antenna configurations, antenna materials, packaging and deployment techniques feasible for SwampSat operation were surveyed. Based on the survey, a dipole antenna design was adopted for SwampSat. The SwampSat antenna system consists of two modules which integrate the structural and electrical components in a non-intrusive manner. The antenna system modules are developed to support an assembly process which can be performed independently and then interfaced to the SwampSat structural frame and electrical components. A burn-wire deployment mechanism has been designed for each module. Prototypes of the antenna system have been fabricated and tested and the final flight design is presented. The antenna system will undergo further field and deployment tests to mitigate any failure modes.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Dante Buckley.
Thesis: Thesis (M.S.)--University of Florida, 2009.
Local: Adviser: Fitz-Coy, Norman G.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2010-06-30

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2009
System ID: UFE0025042:00001


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SWAMPSATANTENNASYSTEM By DANTEAUGUSTUSBUCKLEY ATHESISPRESENTEDTOTHEGRADUATESCHOOL OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT OFTHEREQUIREMENTSFORTHEDEGREEOF MASTEROFSCIENCE UNIVERSITYOFFLORIDA 2009 1

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c r 2009DanteAugustusBuckley 2

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Tomywifewhoinspireseveryday;tomycolleaguesandfriend swhobelieveinme;andto myfamilyespeciallymygirls(Koda,Kenai,&Roxy)whoalway s ~ meandaretherefor me 3

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ACKNOWLEDGMENTS First,ImustthanktheLordforgivingmethestrengthtoacco mplishmythesisand therstpartofmygraduatestudies.ImustthankmyparentsD anielJamesandMary AnnBuckley,fortheirsacricesinorderformetobecomethe manIamandforgiving metheopportunitytopursuehighereducation.Imustthankt heRiverafamily,especially BasilioandYamileRivera,notonlyforentrustingmewithth eirgreatesttreasure,mywife Taryn,butalsoforbelievinginmyaspirations. Withdeepestgratitudeandrespect,IsincerelythankProfe ssorNormanFitz-Coyfor hiseverlastingpatiencewithmeandhisguidanceasmyacade micadvisorandmentorin life.Forhissupportandfaithinme,Iamhumblyhonored.Iow emanythankstothe SpaceSystemsGroup(SSG)-mygraduateteamwithintheDepar tmentofMechanical andAerospaceEngineering.ThankstoShawnAllgeier,Shara nAsundi,KatieCason, ObulpathiChalla,TakashiHirmatsui,SushantKadimdivan, NeerajKohli,FrederickLeve, Xiaoyuan(Sherry)Li,TzuYu(Jimmy)Lin,MatthewMahin,Sha wnMiller,JosueMunoz, VivekNagabhushan,KunalPatankar,KoushtubhRao,TroyRip pere,VictorRobles, SalvatoreTorre,andAndrewWaldrumforbeingmycolleagues andtechnicallysupporting mypassionforsatellites. Imustthankthosewhocreated,participated,andbelievedi ntheestablishment ofthestudent-ledSmallSatelliteDesignClub(SSDC).I'dl iketoalsothanktheGator AmateurRadioClub(GARC)especiallythefacultyadvisoran dmyelmer,Dr.Jay Garlitz,(AA4FL)andthestationmanager,JeCapehart(W4U FL).ImustthankMario deAranzetaandBarbaraBeckforlettingmeaccesstheirfaci litiestoconductmyresearch. ImustthankLarryBradfordforhistechnicalinput.I'dlike tothanktheFloridaSpace GrantConsortium(FSGC)inparticular,Dr.JaydeepMukherj ee,andSpaceFloridafor supportingtheannualFloridaUNiversitySATtellite(FUNS AT)designcompetitionsin whichIgainedvaluableskills.Iwouldalsoliketothankthe CubeSatCommunityfortheir supportandcooperation. 4

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IwouldalsoliketothankDrs.JaniseMcNairandCarolChesne yfortheirguidance andsupportofmyresearcheorts.Iamespeciallyindebtedt oDr.Chesneyforher patienceandunderstandingofthesituationwhichprevente dherfromreceivingfullcredit forhereorts. 5

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TABLEOFCONTENTS page ACKNOWLEDGMENTS .................................4 LISTOFTABLES .....................................8 LISTOFFIGURES ....................................9 ABSTRACT ........................................10 1INTRODUCTION ..................................11 1.1ResearchMotivation ..............................11 1.2CubeSatBackgroundandHeritage ......................12 1.3SwampSat ....................................13 1.4CubeSatCommunications ...........................14 1.5ThesisOutline ..................................15 2SURVEYFORSWAMPSATANTENNA ......................16 2.1SurveyofAntennaCongurations .......................16 2.1.1ParabolicRerectors ...........................16 2.1.2Dipole ..................................17 2.1.3Monopole ................................17 2.1.4Helical ..................................17 2.1.5MicrostripandPatch ..........................18 2.1.6Horn ...................................18 2.2AntennaCongurationSelection ........................18 2.3DipoleAntennaDesignTradeos .......................19 2.4SurveyforSwampSatAntennaMaterial ...................20 2.4.1Nitinol ..................................20 2.4.2TapeSpringSteel ............................20 3SWAMPSATANTENNASYSTEMDESIGN ...................21 3.1TransmitAntennaSystemModule ......................23 3.2ReceiveAntennaSystemModule .......................25 3.3ElectricalComponentsandInterfaces .....................25 3.3.1StensatTransceiver ...........................26 3.3.2SwampSatFlightComputer ......................28 3.3.3ShortCircuitProtection ........................29 3.4SwampSatAntennaSystemMassBudget ...................29 3.5SwampSatAntennaSystemAssemblyProcess ................29 4ANTENNASYSTEMTESTING ..........................31 4.1AntennaDeploymentExperiments ......................31 6

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4.2ImpedanceMatchingandAntennaTuning ..................31 4.3StensatTransceiverTestingandAntennaSystemFieldTe sting .......32 5COMMUNICATIONLOGISTICS ..........................34 5.1FrequencyCoordinationandAllocation ....................34 5.1.1UplinkandDownlinkSpecications ..................34 5.2SwampSatLinkBudget ............................34 5.3MissionControlRoom .............................35 5.4MissionOperationsCenter ...........................35 5.5GENSO .....................................36 6CONCLUSION ....................................39 6.1Conclusion ....................................39 APPENDIX:SWAMPSATANTENNASYSTEMDOCUMENTATION ........40 REFERENCES .......................................55 BIOGRAPHICALSKETCH ................................57 7

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LISTOFTABLES Table page 2-1ProsandconsonantennacongurationssurveyforSwampS at ..........19 3-1Sidecomponentsinvolvedindeterminingantennasystem layout .........22 3-2Theoreticalhalf-wavelengthdipolelengthsandoperat ingfrequencies ......23 3-3Stensattransceiverspecications ..........................27 3-4Antennasystemmassestimatedbudget .......................30 5-1SwampSatlinkbudgetanalysis ...........................35 5-2GatorNationEarthStation(GNES)hardwareandsoftware components ....38 8

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LISTOFFIGURES Figure page 1-1SwampSatengineeringdevelopmentunit(EDU) ..................14 3-1SwampSatlayoutwithcrosseddipoleantennas ...................21 3-2Sectionofthealuminumframeformountingcompositepan els ..........23 3-3Compositepanel(frontandbackviews) ......................23 3-4Transmitantennasystemmodule ..........................24 3-5Receiveantennasystemmodule ...........................26 3-6Stensattransceiver ..................................27 3-7Pig-tailedcoaxialcablefortesting ..........................27 3-8Drawingoftheantennaconnectorassembly ....................28 3-9Viewofthetransmitandreceiveantennamodulesintegra tedtoSwampSat ...30 4-1AnechoicchamberforRFemissiontesting .....................33 5-1GNESworkstationinsidethemissioncontrolroom ................37 5-2GNESUHFandVHFantennas ...........................37 5-3MissionOperationsCenter(MOC)display .....................38 9

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AbstractofThesisPresentedtotheGraduateSchool oftheUniversityofFloridainPartialFulllmentofthe RequirementsfortheDegreeofMasterofScience SWAMPSATANTENNASYSTEM By DanteAugustusBuckley December2009 Chair:NormanFitz-Coy Major:AerospaceEngineering SwampSat,therstCubeSatmissionoftheUniversityofFlor ida,isanon-orbit technologydemonstratorofacompactthree-axisattitudec ontrolsystemcapableofrapid retargetingandprecisionpointing(R2P2).Thisthesisadd ressesthedesignandtestofthe SwampSatantennasystem.Variousantennacongurations,a ntennamaterials,packaging anddeploymenttechniquesfeasibleforSwampSatoperation weresurveyed.Basedonthe survey,adipoleantennadesignwasadoptedforSwampSat. TheSwampSatantennasystemconsistsoftwomoduleswhichin tegratethestructural andelectricalcomponentsinanon-intrusivemanner.Thean tennasystemmodulesare developedtosupportanassemblyprocesswhichcanbeperfor medindependentlyand theninterfacedtotheSwampSatstructuralframeandelectr icalcomponents.Aburn-wire deploymentmechanismhasbeendesignedforeachmodule.Pro totypesoftheantenna systemhavebeenfabricatedandtestedandthenalightdes ignispresented.The antennasystemwillundergofurthereldanddeploymenttes tstomitigateanyfailure modes. 10

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CHAPTER1 INTRODUCTION \Theartofengineeringistotakeabrightideaandwithmoney ,personnel,materials,andtheproperregardfortheenvironmentproducesomet hingthepublicwants atapriceitcanaordtopay"-SourceUnknown 1.1ResearchMotivation ThecurrentUnitedStatesadministrationhasdenedscienc eeducationandtraining asthetargetareasforthenextgeneration[ 10 ].Atthestatelevel,theGovernor's CommissionontheFutureforSpacestated,\Florida'sresid entsfromKeyWestto Pensacolamustembracethestatewideimportanceoftheaero spaceindustry,asitbenets morethanjustthecommunitiesalongtheSpaceCoast.Beyond ourborders,thenation andtheworldmustlearntoseeFloridaasmorethanjustalaun chsitebutalsoahome formanufacturingandassemblyofrockets,satellites,and aircraftandfortheresearch andinnovationthatunderpinsalloftheseindustries"[ 11 ].Internationally,European andAsiannationshavealreadyimplementedaneducationals ystemthatemphasizes scienceandtechnology,andtheirrecentsuccessesandadva ncesinspaceexplorationand technologydevelopmentmaybeadirectconsequenceofit. Sincetraditionalsatellitesareexpensiveandaredesigne dtoaccommodatesophisticated andredundantsystemsforoperations,theyarenotappropri ateforeducationalpurposes [ 5 ].TheemergingCubeSatprogram,however,oersstudentsed ucationalopportunities throughaccesstospacewithacceptablerisksandaordable costs.TheCubeSatprogram providesaknowledge-basedplatformforstudentsandcolla boratorstoassembleandto ventureintothespacefrontier.Thestandard1UCubeSatfor mfactor,a10centimeter cube,poseschallengestoinnovatetechnologyintendedtou tilizecommerciallyavailable partstoobtainrapidresults. Duetotheirlimitedsize,computationalresources,andpow ergenerationcapabilities, CubeSatsoertheuniqueabilitytoprovidetechnologyrese archanddevelopmentas wellaseducationalopportunities.Inadditiontomoreuniv ersitiesjoiningtheresearch 11

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initiative,therecentinterestofgovernmentagenciesand commercialindustrieshave expandedthepossibilitiesoftheCubeSatcommunity[ 21 ]. TheCubeSatconceptembracestheideathatsmallsatellites complementtraditional satellitesandoerthecommunityimprovementsincostands chedulewhichcannot beachievedbythetraditionalsatellites.The3UPolyPicosatelliteOrbitalDeployer (P-POD)isacertiedcontainerwhichholdsuptothree1UCub eSats.P-PODscan beintegratedtovariouslaunchvehiclesworldwideassecon darypayloadsthusoering additionalaccesstospace.CubeSatsarecurrentlyscalabl ein1/2Uincrementsupto3U, however,severalmulti-podcongurationsareunderdevelo pmentwhichcouldsupport additionalcongurations(e.g.,6U,12U)[ 20 ]. TheUniversityofFlorida(UF)isdevelopingaCubeSattodem onstrateaminiaturized attitudecontrolsystemforpico-andnano-satelliteappli cations.Thescopeofthisthesisis theantennasystemselection,integration,anddeployment mechanismfortheUniversityof FloridaCubeSatknownastheSwampSat. 1.2CubeSatBackgroundandHeritage CubeSatshavebecomeagrowingtrendworldwideinuniversit ypico-andnanosatelliteresearchprograms.TheCubeSatconceptwasautho redjointlybyCalifornia PolytechnicStateUniversity(CalPoly-SanLuisObispo)an dStanfordUniversity, andisquicklybecomingastandardforsmallsatellitesinth epico-andnano-satellite classications[ 16 ].Smallsatellitesareclassiedaspico-,nano-,micro-,a ndmini-satellites basedonnominalmassanddimension[ 2 ].TheinitialfocusbehindtheCubeSatprogram wastoallowuniversitiestoengageandtrainstudentsbypro vidingaordableaccessto space.Commercial-O-The-Shelf(COTS)componentsandmin iaturizationofsatellite technologyhaveenabledsuccessfulCubeSatmissionstodat e. Anemergingmarketopportunityhasbecomeevidentasthespa ceindustryembraces theconceptofCubeSats.EntitiessuchastheNationalScien ceFoundation(NSF)[ 12 ], theNationalReconnaissanceOce(NRO)[ 8 ],andNationalAeronauticsandSpace 12

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Administration(NASA)[ 3 ]haveinvestedinsupportingthedevelopmentofCubeSat technologies.NSF'sspace-weatherandatmosphericresear chdepartmentsponsored twouniversityaliated3UCubeSatmissionsin2008plansto continuetheprogram foryearstocome.Additionally,theNSFisalsosupportingt heAdvancedSpace TechnologiesResearchandEngineeringCenter(ASTREC),wh ichisaIndustry/University CollaborativeResearchCenter(I/UCRC)hostedbytheUnive rsityofFloridaandNorth CarolinaStateUniversityaimingtoenhancetheutilityofs mallsatellitesthroughfocused technologyandresearch[ 9 ].TheNRO'sInnovativeExperimentInitiative(IEI)Broad AgencyAnnouncement(BAA)acknowledgedtheneedforadvanc esinseveralcriticalsmall satellitesubsystems.Asaresult,theNROestablishedaCub eSatocecalled Q b X to monitoranddeveloppico-andnano-satellitetechnologies forimprovedsatellitesystems. CubeSatsprovideuniversitiesameanstotrainstudentsfor theworkforceandallow academiatosolveinnovativeproblemswhileprovidingstud entswithprojectmanagement skillsrelatedtospacesystems.Apotentialoutcomewillbe thetransformationof CubeSatsfromeducational"toys"totechnologydemonstrat ors.Additionally,since CubeSatscanhaverelativelyrapiddevelopmentcyclesandq uickturnaroundascompared totraditionalsatellites,businessopportunitiesforthe marebeingdeveloped.However,to trulyrealizesuchbusinessopportunities,appropriatest andardsandcontinuedexpansion oftheinfrastructure(i.e.,secondarypayloads,multi-po dcongurations,andrexiblelaunch opportunities)isnecessary. 1.3SwampSat SwampSatisa1UCubeSatcurrentlyunderdevelopmentattheU niversityofFlorida [ 6 ].TheSwampSatEDUisshowninFig. 1-1 SwampSat'sprimaryobjectiveistodemonstrateacompactth ree-axisattitudecontrol system(comprisedofapyramidalclusterofsinglegimbaled controlmomentgyroscopes) torapidretargetandprecisionpoint(R2P2)pico-and-nano satellites[ 18 ]. 13

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Figure1-1.SwampSatengineeringdevelopmentunit(EDU) 1.4CubeSatCommunications Thecommunicationsubsystemprovidesthecriticallinkbet weenthesatelliteandthe usersontheground.CubeSatscurrentlyuseradio-communic ationsystemsintheVery HighFrequency(VHF),UltraHighFrequency(UHF),SandXama teurradiobands.The abilityoftheCubeSatcommunitytoutilizetheexistingama teurradiocommunityhas expandedthemissionoperationsproleforuniversityCube Sats.Radiofrequency(RF) techniquesarecommonlyimplementedinCubeSatmissionsdu etotheiromnidirectional characteristics,frequencyselection,andworldwidetrac kingcapabilities. CubeSatscurrentlylacktheattitudesensorsandactuators topreciselypointand maintaintheirdesiredorientations.Thusdirectionalins trumentationsuchashighgain antennasarenotyetfeasible.Adirectionalantennacouldi mprovetheantennagainsfor CubeSatsandincreasetheachievabledataratessignicant lybeyondwhatiscurrently available. Asdevelopmentsinattitudesensorsandactuatorsmature,C ubeSatcommunications willimprove.Anincreaseinthepointingcapabilitieswill directlyimpactonthegainof theantenna.AmajorchallengeinCubeSatcommunicationsis toaddressincreasingthe 14

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dataratetransfer.Directionalantennaswouldmaximizeth ethroughputforCubeSat operationsreducingthedependencyonmemorystoredfortel emetryanalysiswhich isverylimited.OnesuchmethodologytoincreaseCubeSatco mmunicationsisby implementingasmallsatellitesensornetworkwhichwouldd istributevariousprocesses acrossseveralCubeSatsinaconstellationwhichinturnwou ldexpandtheutilityof CubeSatcommunications.Butthesatellitelinktolinknetw orkwouldstillrequireradio frequencyantennasystemstocommandandtrackfromthegrou nd[ 17 ]. DuetotheCubeSatsbeinginsertedintheLowEarthOrbit(LEO ),theyhavehigher orbitalvelocitiesandthusneedprecisionpointingandret argetingtocompensate.Which inturnrequirescouplingR2P2withahighlydirectional(i. e.optical)communications instrumentwhichhavebeenproposedbutneedtobefurtherre searchedanddevelopedfor CubeSatmissions[ 7 ]. 1.5ThesisOutline Thisthesisisorganizedasfollows.Chapter1providesanin troductionofthebenets ofaCubeSatprogram(e.g.asaneducationaltool)fordevelo pingscienceandtechnology aswellasintroduceSwampSat,therstUFCubeSatproject. Chapter2explorescommonantennacongurationsandmateri alsandthedesign tradeosfortheantennaselected.AsurveyofexistingCube Satantennasystemswas performedandusedtonalizetheSwampSatantennasystemde sign. Chapter3detailsthedesignsoftheSwampSatantennasystem Chapter4detailsthetestingoftheantennadeploymentands upportingcommunication hardwareforverifyingtheeectivenessoftheantennasyst emdesign. Chapter5discussesthelogisticsofcommunicationsfortra ckingandoperating SwampSat. Chapter6presentstheconclusion. 15

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CHAPTER2 SURVEYFORSWAMPSATANTENNA 2.1SurveyofAntennaCongurations Miniaturizationofantennasforelectronicdevicesandcom putershavebecome agrowinginterestintheantennaeld[ 4 ].Alargeemphasisofthecurrentantenna manufacturersistofocusonsmallbutsmartantennas(i.e., forsmallelectronicssuch ascellphones,laptops,handhelddevices).However,these smartantennasrequirea basestationorexistingnetworktoestablishacommunicati onslinksincelongrange communicationsisnotdesired.Inaddition,fundamentalme chanicallimitations,which hinderthefree-spacewavelengthtoanantennaelementmust bedesigned,presentsa challenge.Space-basedinparticularCubeSatcommunicati onsrequirecommunication signalstotravellongdistanceswhiletostillpenetrateth roughtheatmospherewith minimallosses.Thefollowingsurveyandselectionoftheav ailableantennacongurations iscriticaltothesuccessofSwampSat. TheSwampSatantennacongurationwasselectedkeepinginm indthesemechanical andelectricalfactors: Packaging Rigidity AcceptableGain SucientBandwidth Abriefdescriptionofavailableantennaconceptsisprovid edbelowtomotivatethe antennaselectionprocesswhichisexplainedinthenextsec tions. 2.1.1ParabolicRerectors Aparabolicrerectorisarerectivedevicetocollectorproj ectradiowaves.Parabolic rerectorstransformanincomingplanewavetravelingalong anaxisintoasphericalwave convergingtowardsafocus.Asphericalwavegeneratedbyap ointsourceplacedinthe focusistransformedintoaplanewavepropagatingasacolli matedbeamalongthisaxis. 16

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Theconstructionofaparabolicrerector,though,isnotfea sibleforSwampSatdueto volumeconstraints.2.1.2Dipole Adipoleantennaconsistsofacenter-fedpointwhichsplits intotwoelementsfor transmittingorreceivingradiofrequencyenergy.Thecurr entamplitudeonadipole antennadecreasesuniformlyfrommaximumatthecenter-fed pointtominimumofzero attheelementends.Dipoleantennascenter-fedpointsarec ommonlyimplementedin CubeSatsduetoeaseoftheirpackaginganddeploymentchara cteristics.Thelength ofthedipoleantennaisdirectlyrelatedtotheoperational frequenciessotheantenna lengthscanbedeterminedbasedonthedesiredfrequency.Th egainofadipoleantennais approximately2.14dBiandtheradiationresistanceapprox imatelyis73n. Thedipoleantennacongurationisanappropriatechoicefo rSwampSat. 2.1.3Monopole Amonopoleantennaisatypeofradioantennaformedbyreplac ingonehalfofa dipoleantennawithagroundplanenormaltotheremainingha lf.Ifthegroundplane islargeenough,themonopolebehavesexactlylikeadipole, asifitsrerectioninthe groundplaneformedthemissinghalfofthedipole.However, amonopolehasagainof approximately5.1dBiandtheradiationresistanceisappro ximately36.5n,whichisless. ThemonopoleantennaisappropriatebutisnotselectedforS wampSatduetolower obtainablegainascomparedtoadipole.2.1.4Helical Ahelicalantennaisanantennaconsistingofaconductingwi rewoundintheform ofahelix.Inmostcases,helicalantennasaremountedovera groundplane.Thefareld radiationpatternissimilartoanelectricallyshortdipol eormonopole.Theradiation isdirectedperpendicularontheaxisofthehelix,andadjus tingthediameterofeach ringandtheturnspacebetweeneachhelicalcoilallowsforc ircularpolarization.Helical antennashaveapredictablepattern,gain,andimpedanceov erawidefrequencyrange. 17

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Thedirectionalitydependsonthequantityofhelicalcoilw indings.Asthelengthofthe antennaincreasessodoesthegain. ThehelicalantennaisnotfeasibleforSwampSatduetovolum econstraints. 2.1.5MicrostripandPatch Apatchantennaisanarrowband,wide-beamantennafabricat edbyetchingthe antennaelementpatterninmetaltracebondedtoaninsulati ngdielectricsubstrate.This substratewithacontinuousmetallayerisbondedtotheoppo sitesideofthesubstrate whichformsagroundplane. CubeSatshavenotutilizedmanypatchantennadesignsdueto thechallengesof miniaturizationandparameterspecications.Hence,them icrostripandpatchantennais notfeasiblefortheselectedSwampSatfrequencies.[ 13 ]. 2.1.6Horn Thehorn'sdimensionandshape,placementofthererector,a ndrerector'sdimension andshapealterthebeampattern.Hornantennasaretypicall yimplementedasfeed elementsforlargeradioastronomy,satellitetracking,an dcommunicationdishes.Horn antennaisacommonelementofphasedarraysandservesasaun iversalstandardfor calibrationandgainmeasurementsofhigh-gainantennas[ 4 ]. ThehornantennaisnotfeasibleforSwampSatduetovolumeco nstraints. 2.2AntennaCongurationSelection Selectingthehorn,helical,andparabolicrerectorforaSw ampSatantennasystem isnotfeasibleasthepackagingdicultiescannotbeaccomm odatedonSwampSat's structuraldesign.ThefrequenciesallocatedfortheSwamp Satmissionarewithinthe2 meterbandand70centimeterbandmakingpatchantennasnota pplicableforSwampSat. Utilizationofhigherfrequencieswoulddecreasethedimen sionsofthepatchantennawhich couldbeembeddedwithintheSwampSatstructure.However,p atchantennaswerealso eliminatedfromthedesignbecauseoftheconstraintsonthe availablefrequencyrange. 18

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Theantennacongurationsdenedintheprevioussectionar ecomparedinTable 2-1 .Additionally,asurveyofoperationalCubeSatcommunicat ionsystemsincluding theirtransceiverspecications,transmitfrequencies,m odulations,antennatypes,power outputs,anddatadownloadsarecompiledinRef.[ 15 ].Monopolesanddipolesdominate theCubeSatantennacongurationswhilefewpatchantennas havebeenimplemented. Asaresult,thedipoleantennaisselected. Table2-1.Prosandconsonantennacongurationssurveyfor SwampSat AntennaTypeProsCons Parabolichighgainpackaging,deploymentRerector alignment,highlydirectional Dipoleomnidirectionalityfrequencylowgain dependent,packaging Monopoleomnidirectionality,frequencylowgain, dependent Helicalhighgain,circularpackaginganddeployment polarization,simpleconstructiodeployablevolume Microstrip/Patchnarrowband,smallsize,lowgain nodeployment,frequencydependent Hornhighgain,simplepackagingdiculties, constructionjoints,highly directional 2.3DipoleAntennaDesignTradeos Asthelengthoftheantennadecreases,itsfrequency,andhe nceitswavelength increases.Equation 2{1 describesthisrelationshipwhere 4 isthelengthofasingle elementofahalf-wavedipole,cisthespeedoflight, isthewavelengthofadipole antenna.ForSwampSat,thetransmitandreceivefrequencie sare437.385MHzand 145.980MHz,respectively,resultinginatransmitantenna oflength34.3cmandareceive antennaoflength103cm. 4 = c 4 (2{1) 19

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2.4SurveyforSwampSatAntennaMaterial Severalcharacteristicswereconsideredduringthemateri alselectionfortheSwampSat antennadipoleelements.Thematerialneededtobeelastici nordertotinsidethe CubeSatconstraintswhenstowed,yetunfoldintoitsnomina llengthwhendeployed. Additionally,fabrication(includingtheabilitytosolde r)factoredintotheselectionofthe nalrightantennamaterial.Twomaterialswereconsidered andarediscussedbelow. 2.4.1Nitinol Nitinolisanickeltitaniumalloywhichisknownforitsshap ememorycharacteristics. NitinolwireshaverownonseveralCubeSats[ 15 ].However,anincreasedbandwidthis desiredforSwampSatthusrequiringnitinolstripsrathert hannitinolwires.Furthermore, caremustbetakentofabricatenitinolelementsandsolderc onnectionstonitinol. NitinolwasnotselectedforSwampSatduetothedicultyinp ackagingandthe additionalfabricationchallenges.2.4.2TapeSpringSteel Tapespringsteelisacommonantennamaterialutilizedonse veralCubeSatmissions duetoitsabilitytobepackagedinaconnedvolumeyetdeplo ytoitsdesiredlength whenreleased.Additionally,springsteelfabricationisa straight-forwardprocessthat canbeeasilyaccomplishedinthemootlaboratory.Solderab leconnectionsrequirethat thecoatingberemovedfromthematerial(assumingthemater ialwasobtainedfroma commerciallyavailabletaperule).Anynecessaryholesfor mountinganddeploymentin theantennaelementscanbefabricatedin-house. ThetapespringsteelwasselectedfortheSwampSatduetothe factorsabove. 20

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CHAPTER3 SWAMPSATANTENNASYSTEMDESIGN TheSwampSatantennasystemisdesignedforeaseofintegrat iontotheright hardwaretoaccomplishsuccessfulantennastorage,deploy mentandoperation.The antennasystemismechanicallyintegratedintotheSwampSa tstructureanditelectrically interfacestotheSwampSatcommunicationboard(fortransm ittingandreceiving)and theSwampSatrightcomputerboard(fordeployment).Thestr ucturalandelectrical impactoftheSwampSatantennasystemisaddressedinthedes ign.Theantennasystem consistsoftwomodules:atransmitmoduleandareceivemodu le.TheSwampSatlayout identifyingthefacesanddeployedantennasisshowninFig. 3-1 andrelevantcomponents areidentiedinTable 3-1 .Overall,theantennasystemdesigngoalsare: Modulardesign EaseofintegrationwithSwampSatsystem Minimalmass !"#$%&% !"#$%'% !"#$%(% !"#$%)% !"#$%*% !"#$%+% ,-".%(% ,-".%*% ,-".%)% ,-".%'% Figure3-1.SwampSatlayoutwithcrosseddipoleantennas 21

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Table3-1.Sidecomponentsinvolvedindeterminingantenna systemlayout SideComponent 1Compositepanel ReceiveantennaSolarcellsSunsensor 2Compositepanel USBconnectorRemove-Before-FlightpinMotorcontrollerboardSolarcellsSunsensor 3Compositepanel TransmitantennaMagnetcoilSolarcellsSunsensor 4Compositepanel MagnetcoilJ-TagconnectorMotorcontrollerboardSolarcellsSunsensor 5Compositepanel MagnetcoilSolarcellsSunsensor 6CMGbaseplate Sunsensor Figures 3-2 and 3-3 show,respectively,thesectionofstructuralaluminumfra me andcompositepanel,betweenwhichtheantennasystemissan dwiched.Figure 3-2 also showsoneoftheSwampSatfaceswithscrewholestowhichthea ntennasystemmoduleis attached. Theantennasystemconsistsoftwodierentdelrinplatedes ignsforthetransmitand receivedipoleantennaelements.Themodulesaremountedon oppositesidestoavoidany collisionoftheantennaelementsduringsimultaneousdepl oymentasshowninFig. 3-1 Thetransmitandreceiveantennalengthsandcorresponding frequenciesareshownin 22

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Figure3-2.Sectionofthealuminumframeformountingcompo sitepanels Figure3-3.Compositepanel(frontandbackviews)Table 3-2 andarebasedonEq. 2{1 .Toaccommodatethedierencesinantennalengths, twoseparateantennasystemswererequired,bothofwhichar efabricatedfromdelrin. Table3-2.Theoreticalhalf-wavelengthdipolelengthsand operatingfrequencies TotalLengthFrequency TransmitAntenna34.3cm437.385MHz ReceiveAntenna103cm145.980MHz 3.1TransmitAntennaSystemModule AsshowninTable 3-1 ,side3ofSwampSathousesthetransmitantennaanda magnetcoil.Thetransmitantennasystemissandwichedbetw eentheCubeSatstructure 23

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shownin 3-1 andthecompositepanelshowninFig. 3-3 andmustaccommodatethe thicknessofthemagnetcoilonthebackofthecompositepane l. Thedelrinplateforthetransmitantennaelementsisshowni nFig. 3-4 .Toavoid electricallyshortingtheantenna,araisededgethatinter faceswiththealuminum structuralplateisprovided;noedgeisrequiredforthesid ethatinterfaceswiththe compositepanelsinceshortageisnotpossiblethroughcont act. !"#$%&'()$*&+(#& ,)-./0-.&+#,.$& .(-01/02& !"#$%&'()$&*(#&& "(+,(-./$&& ,01$)& +(21314&& 51/$110& *$$6& ,(.1/-&& 78)(1& 9:$#& 7."'#(+$& &:2#1;%.#$& -3/"'& <$"$--& Figure3-4.Transmitantennasystemmodule Theantennaiswrappedinsideagroovecreatedbythecomposi tepanelandtheback edgeonthedelrinplate.Anylonber(inblue)routesbetwee ntheholeateachtipof thetransmitantennaelementsandrestrainsthemfromdeplo ying.Arecessinthedelrin 24

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plateisdesignedtoaccommodatetheinsertionofthenylon beracrossthedelrinplateto allowforsucientroomfortheassemblyofthedeploymentme chanismandsixholesare intheplateforthe\three-stitches"ofnichromelament(i norange)whichthenylonber passesthrough.Thetransmitantennadeploymentmechanism residesonthemiddleofrail 3(seeFig. 3-1 ).Thenichromelamentisactivatedbyaswitchontherightc omputer, whichwhenactivatedheatsthenichromelamentandseverst henylonberdeploying eachdipolereceiveelementsimultaneouslyintotheirrigh tcongurationforoperation. 3.2ReceiveAntennaSystemModule Thereceivedipoleantennaelementsaremountedonadelrinp lateasindicatedby Fig. 3-5 .Aseparatedesignisnecessarysincethelengthofeachelem entofthereceive dipoleislongerthantheperimeterofthedelrinplate.Inth isdesign,theantennaiscoiled andstoredinsidethecavity.Anylonber(inblue)routesbe tweentheraprestraints (inyellow)oneithersideofthedelrinplate.Theraprestra intsarefreetorotateabout apinslottedinthepivothole.Arecessinthedelrinplateis designedtoaccommodate theinsertionoftheraprestraintendandtoallowsucientr oomtoroutethenylonber placedintension.Thedeploymentmechanism,\three-stitc hes"ofnichromelamentin themiddleofthedelrinplate,isindicatedinFig. 3-5 .Testswereperformedtoensure propercontactbetweenthenylonwireandnichromestitches throughouttheburnprocess. Thesamestitchandburntechniqueisimplementedasonthetr ansmitantennasystem module. Theelectricalcomponentsandinterfacesfortheantennasy stemaredescribedinthe nextsection. 3.3ElectricalComponentsandInterfaces Theelectricalcomponentsandinterfacesfortheantennasy stemintegratetothe StensattransceiverboardandtheSwampSatFlightComputer (SFC430)board. 25

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!"#$%& '$"(%& )*(+"$(& '$"(%& ,-.'& /*+%/."(%& 01-$(& 23*/& 0"45/$6*&37/(89"/*& +:%45& ;(%*((.&<**=&'$"(%+&& >4/*9&5$-*+&<$/& .-76"(76&4/*9&5$-*&<$/&& 4$6'$+"%*&& '.(*-& 6$7(:(?&& Figure3-5.Receiveantennasystemmodule3.3.1StensatTransceiver ACOTScommunicationsboardwaspurchasedforSwampSatfrom StensatInc.The Stensattransceiverboardhasrightheritageandhasrownon severalCubeSatmissions [ 15 ].Table 3-3 includesthetransceiversspecication. ASubMiniatureversionA(SMA)connectorisutilizedforthe Stensattransceiver's transmitandreceiveantennajacksasseeninFig. 3-6 .AcoaxialcablewithanSMA 26

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plugtsontotheStensattransceiver'santennajacksforac onnectiontotheantenna feedpoints.Theantennafeedpointendofthecoaxialcablei spig-tailedasindicatedin Fig. 3-7 andisroutedtothetransmitandreceiveantennafeedpoints wheretheantenna connectorassemblyresides.Table3-3.Stensattransceiverspecications ParameterSpecication Bandwidth30kHzNominalPower1wattTransmitFrequency437.385MHzReceiveFrequency145.980MHzTransmitBaudRate+Modulation1200baud+AFSKReceiveBaudRate+Modulation1200baud+AFSKTransmitBaudRate+Modulation9600baud+FSKPacketProtocolAX.25 !"#$%&'() *$(+$$#) ,#-.) /+-+'0+) *$(+$$#) ,#-.) Figure3-6.Stensattransceiver Figure3-7.Pig-tailedcoaxialcablefortesting Figure 3-8 showsadrawingoftheantennaconnectorassembly.Thetrans mitand receiveantennasystemmoduleshavethesameantennaconnec torassembly.However,the 27

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lengthofthecableisdierentbetweenthetransmitandrece iveantennaasdictatedby thelocationsoftheantennajacksontheStensattransceive randtheantennaconnector assembliesonthetransmitandreceiveantennasystemmodul es,respectively. Figure3-8.Drawingoftheantennaconnectorassembly3.3.2SwampSatFlightComputer Thecircuitrynecessarytoactivatethedeploymentmechani smislocatedonthe SwampSatFlightComputerboard.Toactivatethedeployment device(i.e.,thenichrome lament),aloadswitchwhichisapowerdistributionintegr atedcircuitisused. TheloadswitchimplementedonSwampSatwasselectedduetoi tslow-voltage operation,low-currentconsumption,fasttimingresponse s,smallfootprint,andeaseof use.Thisloadswitchhasaslewratecontrolwhichwhenthede viceisturnedon,the currentfedtotheloadswitchisgraduallysuppliedtopreve ntasuddensurgeofelectricity reducinganydamagepossibletootherSwampSatcomponents. Loadswitchperformance testsareprovidedinchapter4andtheappendix. 28

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Theantennadeploymenttestprocessisdocumentedintheapp endix.Itincludesa descriptionofthecircuitrynecessaryfortestingtheload switchandalsocharacterizingthe severing(i.e.,melting)ofthenylonlamenttodeploythed ipoleantennaelements. 3.3.3ShortCircuitProtection Themajormotivationforimplementingdelrinontheantenna systemmodulesis directlyrelatedtoitsnon-conductiveproperties.Thedel rinplatesprovideaboundaryso thattheantennasdonotshortcircuitwiththesurroundinga luminumframe. Whilethecurrentdesignoftheantennamoduleusingdelrins houldaddressthe concernsofshortcircuitryoftheantennasystem,addition alprocedureswereconsidered. Twoofthesearepresented.First,coatingoftheantennawit hanon-conductivepowder coatwasconsideredbutquicklyeliminatedduetothepotent ialforoutgassingofthe powder.Thesecondoptionconsideredwastoencapsulatethe antennaelementwitha non-conductivekaptonlm.Thiswasnotpursuedbutisanopt iontoconsidershouldit beneeded. 3.4SwampSatAntennaSystemMassBudget TheantennasystemmassbudgetisinTable 3-4 .Theoverallmassoftheantenna systemis35.2grams.Basedonthethedensityofthedelrin,t hemassofthedelrin transmitplateisestimatedat8gramsandthatofthereceive plateat13grams.Themass ofthetransmitdipoleantennais1.8gramsandthemassofthe receivedipoleantennais 5.4grams.Themassofthefastenersnecessarytomountthede lrinplateandcomposite paneltothealuminumframeisestimatedat2grams.Themasso fthecoaxialcablesto interfacetheStensattransceiverandthedipoleantennasi sestimatedat5grams. 3.5SwampSatAntennaSystemAssemblyProcess Astep-by-stepprocessmustbefollowedtoensureproperass emblyoftheantenna modulestothesatellitecube.Eachmoduleisindividuallya ssembledbeforeintegrating tothesatellite;i.e.,theantennaanddeploymentmechanis m(burn-wire)areassembledto thedelrinplate.Oncethemodulesareassembled,theapprop riateelectricalconnections 29

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Table3-4.Antennasystemmassestimatedbudget ComponentMass Delrintransmitplate8gramsDelrinreceiveplate13gramsTransmitdipoleantenna1.8gramsReceivedipoleantenna5.4gramsFasteners2gramsCoaxialcables5grams aremadeandtheassemblyistheninterfacedtoitsrespectiv efaceofthecubestructureas showninFigs. 3-1 and 3-9 .Finally,thecompositepanelsarethenattachedtocomplet e theassembly. Figure3-9.Viewofthetransmitandreceiveantennamodules integratedtoSwampSat 30

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CHAPTER4 ANTENNASYSTEMTESTING Theantennasystemtestingiscomprisedofseveralteststom itigatethefailuremodes foroperation. 4.1AntennaDeploymentExperiments Severalantennadeploymenttestswereconductedtovalidat ethenichromeburn-wire mechanism.Intheseexperiments,theloadswitchwasintegr atedtovariousburnwire congurationstoemulatethedeploymentandtodevelopspec icationsforthedeployment time.Thedetailsoftheexperimentalapparatususedinthes edeploymentareprovidedin theappendix.Ahighspeedcamerawasutilizedtocapturethe deploymentsequenceto observethebehaviorofSwampSatandmotivatefurtheranaly sisforrightdeploymentand operation. Theresultsindicatethatasupplycurrentof500mAissucie nttoseverthenylon berwiththenichromeburn-wiretechnique.Thetimerequir edtocompletelyburnthe nylonlamentatroomconditionsisapproximately1second; vacuumtestsareplannedin ordertocharacterizetheperformanceinspace.Furthertes tingisrequiredfortheactual righthardwarecomponentssincethenaldesignisbasedont hedelrinframewhichwas notavailableatthetimethesedeploymenttestswereconduc ted. 4.2ImpedanceMatchingandAntennaTuning Antennasbehavedierentlyinfreespacethantheydointhev icinityofaconductive material.TheCubeSatstructureismadeofaluminumandwhen theantennaismounted onthestructure,thestructurebehavesasapartoftheanten na.Thisalterstheexpected propertiesoftherequiredlengthofthedipoleantennasand theclassicalequations stillhold.Itisimperativetotunethepropertieswiththea ntennamountedinitsnal orientationontherighthardware.Antennaimpedancehasto bematchedwiththe transmissionlineandinturntransmissionlineimpedanceh astobematchedwiththe Stensattransmitterimpedanceforeciencyandlossreduct ion.Thisisrequiredfor 31

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maximumpowertransferfromtransmittertofreespaceandmi nimizetransmission linererection.Thenominalimpedanceofadipoleantennais 73nwhiletheStensat transceiveris50n. Equation 2{1 isidealandassumestheelectronvelocityintheantennamat erialtobe equaltothespeedoflight.Thisisnotthecaseforspringste el.Afactorof0.9isrequired tocompensateforthenitespeedofelectronsinspringstee l.Theantennasbehave dierentlyduetothealuminumchassisasitsproximityaec tstheresidentelectrons.The 0.9factoriscompensatedsuchthatEq. 2{1 isstillvalid. Theprocedurestoperformimpedancematchingaredocumente dintheappendixand needtobeperformedontherighthardwarewhenitbecomesava ilable. 4.3StensatTransceiverTestingandAntennaSystemFieldTe sting TheStensattransceiverwastestedtoensurethatpropertra nsmissionandreception couldbeestablished.TheCubeSatKitdevelopmentboardwas utilizedinconductingthis experiment.Prototypedipoleantennaswereconnectedtoth eantennajacksonStensat transceiverandtestedwithportableAX.25packetradiosan dalsothegroundstation equipment.Softwarewaswrittentoestablish I 2 C protocolbetweentheStensattransceiver andtherightprocessoranddemonstratetelemetrytransmis sion. Initialtestingwasperformedonthebandwidthandemission softheStensat transceiveratTimcoEngineering,alocalcompanywhichpro videsFederalCommissions Committee(FCC)certicationforRFcommunicationdevices .Theprocedureandresults ofthesetestsareintheappendix. Oncetherighthardwareisassembled,ElectricalMagneticI nterference(EMI)tests willbeperformedatTimcoEngineeringonallSwampSatelect ronicstoensurenospurious transmissionsasseverallaunchguidelinesrequiresecond arypayloadstonotinterferewith primarypayloads. Figure 4-1 showstheanechoicchamberatTimcoEngineeringwhichwillb eutilizedto conductthesetests. 32

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Figure4-1.AnechoicchamberforRFemissiontesting 33

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CHAPTER5 COMMUNICATIONLOGISTICS 5.1FrequencyCoordinationandAllocation Theantennassystemwasdesignedtosatisfythefrequencies allocatedtoSwampSat bytheInternationalAmateurRadioUnion(IARU).TheUniver sityofFloridaappliedto theIARUforitsfrequencycoordinationinDecember2006and onJanuary14,2007was grantedanuplinkfrequencyof145.980MHzandadownlinkfre quencyof437.385MHz. TheUniversityofFloridaissubmittingnoticationandupd atestotheIARUand FederalCommunicationsCommittee(FCC)tosatisfyRulesan dRegulationssubpartC, specialoperations,(Part97.207subparagraphg)asadopte donMay31,1989. Additionally,theSwampSatcallsign(WG4SAT)hasbeenassi gnedbytheFCC.The primarygroundstationandmissioncontrolroomisintheW4D FUradiostationaliated withthestudentorganizationknownastheGatorAmateurRad ioClub(GARC)[ 1 ]. 5.1.1UplinkandDownlinkSpecications TheuplinkanddownlinkcommunicationsusetheAX.25amateu rradioprotocol. TheAX.25protocolallowsupto200charactersperpacket.On lytext,punctuation,and numericalASCIIcharactersarepermitted.Theuplink(GNES toSwampSat)willoperate intheVeryHighFrequency(VHF)bandatthecarrierfrequenc yof145.980MHz.The AudioFrequency-ShiftKeying(AFSK)modulationschemeisu tilized,allowingfora1200 baudreceivedatarateatSwampSat.Thedownlink(SwampSatt oGNES)willoperatein theUltraHighFrequency(UHF)atacarrierfrequencyof437. 385MHz.Thetransmitter canoperateintwomodes:1200baudAFSKand9600baudFrequen cy-ShiftKeying (FSK).Thetransmitterconsumesapproximately1wattofpow erwhileactive. 5.2SwampSatLinkBudget Acommunicationslinkbudgetisnecessarytoensurethatali nkcanbeestablished betweenthesatelliteandtheground,andtocalculatethema rginswhichareacceptable. TheSwampSatlinkbudgetwasdevelopedusingtheavailables preadsheetadoptedbythe 34

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IARUandtheAmateurRadioSatelliteCorporation(AMSAT)[ 14 ].Table 5-1 showsthe resultsofthelinkbudget.Table5-1.SwampSatlinkbudgetanalysis Item SymbolUnitsData ReceiveFrequency RX MHz145.980 TransmitFrequency TX MHz437.385 TransmitterPower P TX Watts1 TransmitterPower P TX dBW0 SwampSatAntennaGain G t dBi2.2 SwampSatPointingLoss Pl dB.1 SwampSatPolarizationLoss e r dB.23 SwampSatEquiv.IsotropicRadiatedPowerEIRPdBW2.1GNESPower P RX Watts100 GNESPower P RX dBW2 GNESAntennaGain G RX dBi12.8 GNESPointingLoss Pl dB.3 GNESAntennaPolarizationLoss e r dB.23 GNESPointingLoss Pl dB.3 GNESLinkMargin-dB46.7SwampSatLinkMargin-dB25.7 5.3MissionControlRoom TheSwampSatantennasystemisdesignedtoestablishthecom municationslink betweenthemissionoperationsteamonthegroundandSwampS at.Themissioncontrol roomforSwampSatislocatedinsidetheradiostationownedb ytheGatorAmateur RadioClub.A2meterVHFuplinkand70centimeterUHFdownlin kisachievedviatwo righthandedcircularlypolarizedYagiantennas.Theanten nasperformsatellitetracking throughazimuthandelevationrotors.Uplinkcommandsandt elemetrydownlinkingis accomplishedthroughthedigitalcommunicationssoftware .Thesatelliteequipmentshown inFigs. 5-1 and 5-2 isreferredtoastheGatorNationEarthStation(GNES).TheG NES hardwareandsoftwarecomponentsarelistedinTable 5-2 5.4MissionOperationsCenter TheMissionOperationsCenter(MOC)isutilizedforcoordin atingsatellitecontacts andanalyzingtelemetry(seeFig. 5-3 ).Thefacilityusestrackingsoftwarewhichis 35

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identicalthatusedinthemissioncontrolroom.Thepurpose oftheMOCistomake missiondecisionsbasedoncomputersimulationsandteleme tryanalysis.TheMOCalso providesnon-FCClicensedteammembersandcollaboratorst heopportunitytoparticipate inSwampSatactivities.ItshouldbenotedthatonlyFCClice nsedtechniciansareallowed tocommandandoperatetheGNESequipment.Plansarebeingde velopedtoupgrade GNESandtheMOCtomakethemcompatiblewithothernationala ndinternational groundstationnetworks[ 22 ]. 5.5GENSO TheGlobalEducationalNetworkforSatelliteOperations(G ENSO)isaninitiativeby theEuropeanSpaceAgency'sEducationalDepartmentinitia tedin2006thatinterconnects aworldwidenetworkofgroundstationsviainternetenabled software.Themainfocus istoprovideanincreasedcoveragefortrackingandoperati ngeducationalsatellitesand educationalmissions.SinceCubeSatsareoperatinginLowE arthOrbit(LEO),theyhave increasedorbitalspeedsanddecreasedswathcoveragescom paredtosatellitesinhigher altitudes.Therefore,alimitedcommunicationswindowove rasinglegroundstationposes achallengetoCubeSatmissionoperatorstoacquireknowled geandbehavioroftheir respectiveCubeSats.GENSOiscoordinatingwithdistribut edinstitutionsandamateur radiogroundoperatorsworldwidetoincreasethecoveragea vailable.AGENSO-compliant spacecrafthasasetpriorityandotherrestrictionsastowh ichgroundstationshalloperate atagiventime.TheUniversityofFlorida'sGNEShassubmitt edarequesttojoinand havebeeninvitedtoparticipateinthelimitedsoftwarerel easeinthefourthquarterof 2009[ 19 ]. 36

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Figure5-1.GNESworkstationinsidethemissioncontrolroo m Figure5-2.GNESUHFandVHFantennas 37

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Table5-2.GatorNationEarthStation(GNES)hardwareandso ftwarecomponents Hardware iCOM910HdualbandtransceiverKantronicsKPC-9612TNCYaesuG-5500RotorcontrollerGS-232BrotorcontrolinterfaceMirageKP-2downlinkpreamplierHy-GainUB-7030SATUHFYagiantennaHy-Gain216SVHFYagiantenna Sotftware SatPC32OrbitronWinAOSWinListenWiSPDDESatelliteToolKit Figure5-3.MissionOperationsCenter(MOC)display 38

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CHAPTER6 CONCLUSION 6.1Conclusion SwampSatisatechnologydemonstratorofahighlyintegrate dandinnovativesatellite systemfollowingtheCubeSatstandard.Theantennasystemd escribedinthisthesis representanappropriatesolutionfortheSwampSatcommuni cationrequirements. Basedonthisdesign,righthardwareisbeingprocuredforn alassemblyandtestof theintegratedSwampSat. 39

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APPENDIX:SWAMPSATANTENNASYSTEMDOCUMENTATION 40

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Subsystem: Communications Document No.: 09/A1/TD/05/05 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ NEB185A Test No.: 1 SwampSat Test Report 41 Objective To test burn wire techniques to deploy pa ckaged antennas and conduct various experiments to verify the deployment mechanism Material Required: Fig. 1 SwampSat EDU Fig. 2 Antenna Deployment Push Button Box Fig. 3 Nichrome Filament Fig. 4: Load Switches Fig. 5: Nylon Fiber Fig. 6: Power Supply Fig. 7: PVC Quarter-Round Guides Figure 8: Nitinol Transmit and Receive Dipole Antenna Elements Special Instructions The SwampSat flight computer board supplies 3. 3 V to the load switch implemented for the antenna deployments. Fig. 2 was constructed with two load switches within and the necessary resistors to implement the manual switch and reset the load switch. The yellow button indicated

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Subsystem: Communications Document No.: 09/A1/TD/05/05 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ NEB185A Test No.: 1 SwampSat Test Report 42 in Fig.2 is the manual switch to activate and de-activate the current supplied to the burn wire which is representative if similar circuitry on the SwampSat flight computer. Figure 9 shows the circuitry for the antenna deployment box. Fig. 9 Antenna Deployment Box Circuit Diagram Procedure This procedure was applied to both transmit and receive dipole antennas. The antennas mounted with the two holes to the delrin antenna mount on the CubeSat frame and the single hole to package the antenna elements. Fig. 10 Two holes for mounting and one for packaging Step 1) Wind the antenna around the groove between the composite panel and edge of the satellites chassis shown in Fig. 11-14. Figure 7 is mounted to the CubeSat as shown in Fig. 11. Fig. 11 Groove featuring quarter-round guides

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Subsystem: Communications Document No.: 09/A1/TD/05/05 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ NEB185A Test No.: 1 SwampSat Test Report 43 Step 2) Apply tension with your fingers w hen wrapping around the quarter-round guides to ensure the antenna is flush. No part of the antenna should protrude out beyond the composite face as illustrated in the following Figs 12-14. Use the nylon filament in Fig. 5 to package the antennas in tension. Fig. 12 Antenna in Groove Fig. 13 Flush from the top view Fig 14. Flush from the side Step 3) The composite panel edge (shown in the Fig. 15 with the blue line) must be flush with the edge of the Cube frame (shown in red) to ensure the antenna deploys and does not collide with any protrusion of the composite panel edge. Fig. 15 Flush Edge Step 4) The total length of the nichrome filament must be kept as short as possible to keep the resistance low. Standard gauge wires can be used to extend the nichrome filament connection to the circuitry. This is required to generate sufficient current at a voltage of 3.3 volts. The nichrome filament is coiled around the nylon fiber which is restraining the antennas from deploying. Step 5) The coils on both the antennas have been connected to the load switch parallel because the load switch has the capability to supply sufficient current for both the coils. Step 6) When all the preparation is complete, push the yellow button on the deployment box can activate the load switch. Stay clear of the ant ennas deploying to prevent any injuries. When the load switch is activated, the nichrome filament will heat to melt the nylon fibers to ultimately deploy the antennas into their dipole configurations (see Figs. 16 and 17).

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Subsystem: Communications Document No.: 09/A1/TD/05/05 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ NEB185A Test No.: 1 SwampSat Test Report 44 Test Data Setup was completed and tests were carried out multiple times. A current of 500 mA was sufficient burn through the nylon fibers to deploy the antennas. This is a safe estimate with 300 mA enough to barely melt the nylon fibers. Thus it turns out to be around 1 A for both nichrome wire. The switch has to be activated for around 45 seconds to make sure the nylon is melted, but further tests need to be conducted inside a vacuum. The nichrome burn wire has a distinctively red glow when initiated. Results Satisfactory results were obtained with respect to the electronics set up. The current limiting resistor required was around 6.8 k (limited to 1 A) in the deployment circuitry. The switch/ON pin has 10 k pull-up resistor since there is no internal pull up. The pin is active low. Figure 16 Deployed transmit antenna

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Subsystem: Communications Document No.: 09/A1/TD/05/05 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ NEB185A Test No.: 1 SwampSat Test Report 45 Figure 17 Deployed receive antenna

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Subsystem: Communications Document Number: 09/A1/TD/03/01 Part No. Begin: 6/29/09 End: 6/29/09 Tested By: Dante @ Brain Institute, AMRIS RF Lab, Rm LG 100 Test No.: N/A SwampSat Test Report 46 Objective To match the impedance for the dipole antenna (73 ) and radio (50 ) and effectively tune the antennas to the appropriate frequencies. Also to figure out the resonant frequency of the dipole transmit and receive. Materials Required The SwampSat EDU in Fig. 1 tested throughout this document precedes the one mentioned in this thesis. The flight design presented in this thesis is still relevant because the antenna mounts are constructed out of a delrin plate as seen in Fig 3. Fig. 1 SwampSat EDU Fig. 2 Network Analyzer Fig. 3 Delrin antenna mount and antenna connector prototype Fig. 4 Short Circuit Cap Fig. 5 SMA-to-BNC Connectors Fig. 6 50 termination Test Personnel Permission granted by: Barbara Beck Dante Buckley Sushant Kadimdivan Timothy Bowen

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Subsystem: Communications Document Number: 09/A1/TD/03/01 Part No. Begin: 6/29/09 End: 6/29/09 Tested By: Dante @ Brain Institute, AMRIS RF Lab, Rm LG 100 Test No.: N/A SwampSat Test Report 47 Special Instructions Due to the imperfections in the integration of the EDU and the delrin antenna mount (shown in Fig. 7), a contact between the antenna element and a mounting screw to the EDU frame creates a short circuit. As a result, the screws, which mount the delrin to the aluminum frame, had to be removed for this test. Fig. 7 EDU and Delrin Antenna Mount Familiarity of the Smith Chart is helpful w hen performing this antenna test (see Fig. 8). The Smith Chart can be used to represent many parameters including impedances, admittances, reflection coefficients, scattering parameters, noise figure circles, constant, gain contours, and regions for unconditional stability. Fig. 8 Smith Chart Theory: The frequency of operation of an antenna is set by the length of the antenna elements. For a half wave dipole the total antenna length is equal to the half wavelength of the desired operating frequency. The dipole is said to be resonant at that frequency. In other words the antenna impedance does not have any imaginary part at the frequency of resonance. This document illustrates the procedure to find out the resonant frequency of the antennas.

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Subsystem: Communications Document Number: 09/A1/TD/03/01 Part No. Begin: 6/29/09 End: 6/29/09 Tested By: Dante @ Brain Institute, AMRIS RF Lab, Rm LG 100 Test No.: N/A SwampSat Test Report 48 Procedure The network analyzer has a female BNC connector at the reflection-test port. The coaxial cable, which plugs onto the Stensat transceiver antenna jack, is routed outside the EDU for these tests for convenience as shown in Fig 1. Hence an appropriate converter from a male SMA to a female BNC should be used as seen in Fig. 4. If necessary, use an extension cable to connect the antenna to the network analyzer. This is to make sure that the antenna is kept sufficiently away from the network analyzer metal chassis, so that interference is mitigated. Every time the network analyzer is booted up or when the operating frequency spectrum is changed, it has to be calibrated The steps to be followed for the same have been illustrated below. A perfect short and a perfect load (50 ) termination, shown respectively in Figs. 5 and 6, are needed to perform the calibration. Calibration of the network Analyzera. Start the network analyzer and set the center frequency and span of the frequency spectrum to be analyzed. This can be done by hitting the center button on the network analyzer front panel (stimulus subsection) followed by keying in the desired frequency from the keypad. The same should be performed for setting the span with the span key. b. Next, press CAL button. c. Press Calibrate Menu. d. Press Reflection Port 1. e. Keep the Reflection Port unconnected. f. Press Open Female. g. Press Done. h. Repeat the steps (e through g) for the short and 50 but with perfect short and perfect load terminations at the reflection-test port respectively. The gender of the termination is male for the short and perfect load terminations. Fig. 9 50 termination Fig. 10 Antenna Impedance Testing Testing the Resonant Frequency 1. Calibrate the network analyzer for a center frequency of 440 MHz and a total span of 800MHz which the effective spectrum displayed on the network analyzer screen is 40MHz to 840MHz. This gives a range where both transmit and receive antennas can be

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Subsystem: Communications Document Number: 09/A1/TD/03/01 Part No. Begin: 6/29/09 End: 6/29/09 Tested By: Dante @ Brain Institute, AMRIS RF Lab, Rm LG 100 Test No.: N/A SwampSat Test Report 49 analyzed with the same calibration. This range can be reduced to increase the resolution and focus at either the 2m band or the 70 cm band. 2. Press the Format key on the display sub-section of the network analyzer. From the options displayed on the right side of the disp lay, select linear display.Smith Chart can be selected from the format menu if desired. 3. Connect the antenna, if not already connected. The plot of the reflected power at different frequencies will be seen on the display. The frequency which has the least power reflected has the least impedance mismatch and is the resonant frequency. The antenna may have a resonance at multiple harmonics. The fundamental will usually show the lowest dip on the plot as seen in Fig. 13. Fig. 13 Transmit Frequency Spike Fig.14 Smith Chart Reading Both receive and transmit antennas were tested for their resonant frequencies and the results are shown in the table below. Since the EDU chassis is made of metal, it modifies the near-field distribution of the antenna. Hence, two readings were recorded, one with the antenna mounted on top of the chassis and the other sufficiently away from the metal chassis. Observations: Table 1 and Table 2 respectively show the observed resonant frequency for the antenna in free space. The extension cable assisted in moving the antenna elements as far so that taking it any farther did not make any difference in the impedance plots on the network analyzer. Table 1 Antenna in free-space (away from EDU) Length (cm) Observed Resonant Freq. (MHz) Calculated Resonant Freq.* (MHz) Receive 25.4 270 295 Transmit 16.4 393 457 *Velocity propagation factor for steel has not been considered while calculating theoretical frequency of resonance.

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Subsystem: Communications Document Number: 09/A1/TD/03/01 Part No. Begin: 6/29/09 End: 6/29/09 Tested By: Dante @ Brain Institute, AMRIS RF Lab, Rm LG 100 Test No.: N/A SwampSat Test Report 50 Table 2 Antenna tested on the derlin mount on the EDU Dipole Element Length (cm) Observed Resonant Freq. (MHz) Calculated Resonant Freq.* (MHz) Receive 25.4 297 295 Transmit 16.4 439 457 *Velocity propagation factor for steel has not been considered while calculating theoretical frequency of resonance. RESULTS: The results show that placing the antenna to the EDU structure tends to increase the resonant frequency. Hence, all further antenna tuning especially as flight hardware becomes available should be matched so the antenna elements can be altered. Also it is seen in Table 2 that when placed on the EDU, the transmit antenna is tuned approximately at 439MHz, which is the desired resonant transmit frequency of 437.385 which is sufficiently tuned and the transmit dipole length seems to be accurate with respect to the current EDU. However, the receive antennas performed for this test were not tuned appropriately. The receive antenna has to be tuned to the 2m band (~145 MHz). The receive dipole antenna tested here was approximately half length of the antenna length design presented. The results of the test seem accurate since the antenna increases by half then the frequency decreases by half. It can be noted that halving the frequency results in 148.5 MHz which is about 3.5 MHz away from the theoretical value needed for the receive antenna dipole. One of the other important observations is noticing the narrowness of the valley on the network analyzer plots. If the valley representing the region of least reflection is wider, the bandwidth is wider. The reduction of the antenna width may provide enough bandwidth to handle the telemetry on SwampSat. Further tests will be conducted to address this situation. Packaging, mass reduction, and operation will need to be addressed in reducing the Also, one more important observation is that when placed near the EDU, the measured frequency of resonance corresponds more closely to the ideally-calculated frequency, i.e. neglecting the velocity propagation factor of the antenna material. This provides us with an empirical formula for calculating the frequency of resonance when mounted on the EDU. Empirical formula: /4 = c / ( 4* ) [2-1] where: c = speed of light = operating frequency /4 = dipole antenna length

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Subsystem: Communications Document No.: 09/A1/TD/05/01 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ Timco Eng. RF Laboratory Test No.: 1 SwampSat Test Report 51 Objective To measure the transmission bandwidth of the Stensat transceiver for the SwampSat communications subsystem Material Required: Fig.1 Spectrum Analyzer Fig. 2 CubeSat Developmen t Board Fig. 3 Kenwood Dual Band with Stensat Transceiver Handheld Transceiver (HT) Test Personnel Permission granted by: Mario de Aranzeta, Timco Engineering Dante Buckley Shawn Allgeier Victor Robles Special Instructions The transceiver should always be operated with a load attached (e.g. an antenna, dummy load, or measuring device). Operating the transmitte r without a load produces unnecessary wear. Procedure The Stensat transceiver characterization was performed at Timco Engineering, a local company in Newberry, FL that performs FCC certifications for RF devices. 1. Setup the Stensat Transceiver and CubeSat Development board for operation in Fig. 2. Use the Kenwood HT to confirm that the transmitter is operating. The HT can be connected to a computer with terminal software (e.g. Hyperterminal) to verify that the data is successfully modulated / demodulated, and that the signal is therefore representative of the transmitters intended output. 2. Connect the Stensat transceiver terminals (SMA connector) into the spectrum analyzer (Fig 1) using a SMA connector.

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Subsystem: Communications Document No.: 09/A1/TD/05/01 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ Timco Eng. RF Laboratory Test No.: 1 SwampSat Test Report 52 3. When setup is complete utilize the spectrum analyzer to sweep the frequency spectrum and measure the spectral density, spurious emission levels, and emitted power. Test Data The bandwidth of the emitted signal was measured for levels of -3 dB, -20 dB, -60 dB at a signal rate of 1200 baud, with the carrier (437.385 MHz) referenced as 0 dB. Plots of the measured bandwidths are shown in ( Fig. 2 Fig. 4 Fig. 6 ). The measure values for bandwidth are listed in Table 1 Note that -60 dB lies within the noise level of the measurement equipment. The measurement values for spurious harmonic emission are listed in Table 2 Results: Table 1: Bandwidth Measurements dB Bandwidth -3 12.4 KHz -20 23.6 KHz -60 800 KHz Figure 1: -3 dB Bandwidth Measurement

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Subsystem: Communications Document No.: 09/A1/TD/05/01 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ Timco Eng. RF Laboratory Test No.: 1 SwampSat Test Report 53 Figure 2: -20 dB Bandwidth Measurement Figure 3: -60 dB Bandwidth Measurement

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Subsystem: Communications Document No.: 09/A1/TD/05/01 Part No. Begin: 03/27/09 End: 03/27/09 Tested By: Dante @ Timco Eng. RF Laboratory Test No.: 1 SwampSat Test Report 54 Table 2: Harmonic Levels Harmonic dBc 1 st (437 MHz) 0 2 nd (874 MHz) 55 3 rd (1,312 MHz) 63 4 th (1,749 MHz) > -86 5 th (2,186 MHz) > -86 The measured power delivered to the antenna terminals of the Stensat transmitter is 1.047 W (+30.2 dBm).

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REFERENCES [1]\AmateurSatelliteFrequencyCoordination."Tech.rep .,InternationalAmateur RadioUnion,[Accessed7/29/09].URL http://www.amsat.org.uk/iaru/finished.asp [2]\SmallSatelliteHomePage."Tech.rep.,SurreyUnivers ity,[Accessed7/29/2009]. URL http://centaur.sstl.co.uk/SSHP/ [3]\FY2006InternalResearchandDevelopmentProgram."Te ch.rep.,NASAGoddard SpaceFlightCenter,[Accessedon7/29/09].URL gsfctechnology.gsfc.nasa.gov [4]Balanis,Constantine. AntennaTheoryAnalysisandDesign .JohnWileyandSons, Inc.,1997. [5]Brenizer,AndrewsS.HoganG.,D.\AStandardSatelliteB usforNationalSecurity SpaceMissions."Tech.rep.,MITLincolnLaboratory,2005. [6]Buckley,DanteandAllgeier,Shawn.\SmallSatelliteDe signClubHomePage."Tech. rep.,UniversityofFlorida,[Accessedon7/29/09].URL www.ufsmallsat.com [7]Club,SmallSatellliteDesign.\UFFUNSATV:DetailedDe signReport."Tech.rep., UniversityofFlorida,2009. [8]Droz,JessicaandBournes,Patrick.\NationalReconnai ssanceOceBroadAgency AnnouncementforInnovoativeEexperimentsInitiative."T ech.rep.,National ReconnaissanceOce'sAcquisitionResearchCenter(ARC), 2008. [9]Fitz-Coy,NormanandEdmonson,W.\AdvancedSpaceTechn ologyResearchand EngineeringCenterProposal."Tech.rep.,UniversityofFl oridaandNorthCarolina StateUniversity,2008[Acessed7/29/2009].URL www.astrec.us [10]Frazier,Kendrick.\Science,Reason,andObamaAdmini stration."([Accessedon 7/29/09]).URL http://www.csicop.org/si/2009-02/obama-admin.html [11]Jennings,Tonietal.\Governor'sCommissionontheFut ureofSpace."Tech.rep., OceofTourism,Trade,andEconomicDevelopment,Jan2006. [12]Jorgensen,T.M.\CubeSat-basedScienceMissionsforS paceWeatherand AtmosphericResearch."Tech.rep.,NationalScienceFound ation,2008. 55

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[13]Kakoyiannis,Constatinou.\ACompactMicrostripAnte nnawithTaperedPeripheral SlitsforCubeSatRFPayloadsat436MHz:Miniaturization,t echniques,design& numericalresults."2008. [14]King,Jan. IARU/AMSATLinkBudgetSpreadsheet .AmateurRadioSatellite Corporation.,[AccessedJuly29,2009].URL http://www.amsat.org.uk/iaru/spreadsheet1.asp [15]Klofas,B.andAnderson,J.\ASurveyofCubeSatCommuni cationSystems." CaliforniaPolytechnicStateUniversity,2008. [16]Martin,AndersonandBartamian. CommunicationSatellites .TheAerospacePress, 2007. [17]McNair,Janise,Fitz-Coy,Norman,Li,X.,andBuckley, Dante.\SmallSatellite SensorNetworks.",2008.SubmittedtoIEEECommunications Magazine. [18]Nagabhushan,Vivek. DevelopmentofControlMomentGyroscopesforAttitude Control .Master'sthesis,UniversityofFlorida,2009. [19]Page,Helen.\GENSO:TheGlobalEducationalNetworkfo rSatelliteOperations." InternationalAstronauticalConference .2008. [20]Puig-Suari,Jordi,Turner,Clark,andTwiggs,RobertJ .\CubeSat:TheDevelopment andLaunchSupportInfrastructureforEighteenDierentSa telliteCustomersonOne Launch."2007. [21]Thomsen,Michael.\Cubesats-HowSmallCanSatellites Get?" SatMagazine ([Accessed7/29/09]).URL http://www.satmagazine.com/cgi-bin/display_article. cgi?number=1556330976 [22]Vega,Karla.\SatelliteControlCenterOperations."T ech.rep.,TheUnivesityof TexasatAustin,2008. 56

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BIOGRAPHICALSKETCH DanteAugustusBuckleywasborninDecemberof1982inCincin nati,Ohio.Hegrew upinCincinnatiuntil1991.Between1991and1998,heandhis familymovedbetween MontgomeryAlabamatoCharlestonSouthCarolinaandOmahaN ebraskaandnally residesinthestateofFlorida.Growingup,hewasanactivea thleteplayingbaseball, basketball,football,andhisfavoritesportsoccer.Dante isahighschoolgraduateat BishopMooreHighSchoolinOrlando,FLin2001andwasamembe rofthe2000State Championshipsoccerteam.Dantemethiswife-to-beatBisho pMoore.Dantebecamea UnitedStatesSoccerFederation(USSF)refereein1997andi scurrentlyanaspiringState 5USSFreferee,aFloridaHighSchoolAthleticsAssociation (FHSAA)highschoolocial, andalsoaNationalCollegiateAthleticAssociation(NCAA) soccerocial.Additionally, Dantesupportsthelocalsoccercommunityasarefereeliais onandrefereeleagueand tournamentassignor. DantewasacceptedintotheUniversityofFlorida'sCollege ofEngineeringin2001. Heiscreditedforco-foundingtheUniversityofFlorida'sS mallSatelliteDesignClub (SSDC)in2005afterbeingselectedtocompeteintheFrankJ. Reddstudentcompetition atthe19thAnnualUSU/AIAASmallSatelliteConferenceinLo gan,Utah.Danteis accountableforleadingtheGatorAmateurRadioClubeortb ysolicitingfundsand technicalinputtoupgradetheW4DFUradiostationestablis hingtheGatorNation EarthStation.DantebecameaFCCcertiedtechnicianwitht hecall-sign,KI4LDJ. DanteisthecurrentSSDCPresident.SSDC'sprimarygoalist oestablishapermanent smallsatelliteprogramoncampus.ThroughDante'sleaders hip,SSDCfocuseditseorts towardswinningtheAnnualFloridaUniversitySatelliteDe signcompetitionsponsoredby theFloridaSpaceGrantConsortiumandSpaceFloridadoings oin2008and2009.Dante isalsocreditedforestablishingandcoordinatingtheAnnu alCubeSatAppreciationDay, whichfocusesasingledaytocreateawarenessoftheUFandCu beSatcommunityinhigh 57

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hopestoestablishingandparticipatinginaneducationalo utreachprogramCubeSats, whichinreturnjustmayinspirethenextgenerationofscien tistsandengineers. DantereceivedhisBachelorsinScience(B.S.)inAerospace Engineeringin2006 andcontinuedhissatelliteresearchwiththeSpaceSystems GroupadvisedbyProfessor NormanFitz-Coy.TheSpaceSystemGroupprovidestechnical supporttotheCubeSat missionknownasSwampSat.InNovember2008,ASTREC,theAdv ancedSpace TechnologiesResearchandEngineeringCenterwasestablis hedfocusingonaparadigmto transformpico-andnano-satellitetechnologiesforincre asedutilityinon-orbitcapabilities. DantereceivedhisMastersofScience(M.S.)fromtheUniver sityofFloridainthesummer of2009.DanteplanstocontinuehisstudiesattheUniversit yofFloridainpursuitofa careerintheemergingsmallsatellitesector. Dantemarriedhisbetterhalf,TarynRivera,onJune28,2008 atSt.JamesCathedral inOrlando,FL.DantecoachesandvolunteersatGirlsPlaceI nc.tospendtimewith hiswife,Taryn.TarynistheAthleticDirectoratGirlsPlac eInc.formerlyknownas GirlsClubofAlachuaCounty,alocalnon-protorganizatio ndedicatedtoempowering girlsofallracial,religiousandeconomicbackgroundstog rowcondent,strong,and independentinordertothriveintheworldaroundthem.Dant eandTaryncurrently resideinGainesville,butenjoytotravelandvisitwithfri endsandfamilyfrequently. 58