Large Aperture Telescope Technology - ADONI...
Transcript of Large Aperture Telescope Technology - ADONI...
LATT:LargeApertureTelescopeTechnology
Xompero,M.,Briguglio,R.,Lisi,F.,Arcidiacono,C.,Riccardi,A.
fromgroundadaptivesecondaries
toaspaceactiveprimary
CGS S.p.A.: coordinator
ADS International: mech. System
MICROGATE: electr.+control systems+testing
CNR-INO Italian Optics Inst.: shell
INAF-Italian Astrophysics Inst.:
AO expertise+optical testing
ESA
INO
C.Vettore, F. Duo
D.Gallieni, M.Tintori, P.Lazzarini
R. Biasi, C.Patauner
F. D’Amato, M. Pucci
R. Briguglio, M. Xompero, A. Riccardi, F. Lisi’
L. Maresi, A. Zuccaro Marchi, J. Pereira do Carmo
TheLATTTeam
LATT?Conceptanddemonstrator
• Is our response totheneeds ofspacemirrors:• Largeformat• Possiblydeployable/segmented• Lightweighted• Activelyshaped
• Scientificcases• Astronomicaltelescope• LIDAR• Earthmonitoring• Telecommunications
Preliminarystudy:*ALCprojectin2007LATTprototyping:*ESTEC/ContractNo.22321/09/NL/RAExpertisefromLBT672,DSM,M4DP:Technologies,strategies,procedures
Actually our secretgoalwastofix theESAlogo!!!
LATTcanhandleit!
Projectstatus
• Endedinoctober2015withfinalreview@ESA-ESTEC:
• Lightweigth:betterthanJWST• Actuatorstroke>>competitors• Powerconsumption:almostnegligible• Concept:veryattractiveforfuturedevelopments
• PresentedatSpaceActiveOptics@ESTEC(nov.2015)
• Unique oflargeformat,deformable• Uniqueconceptaddressing segmentation• Unique applicable toprimary mirror concept
LATT:400mm,F/6sphere,19acts
• CFRP+AlhoneycombReferenceBody(<9 kg/m2)
• Co-located,contactless,position capacitivesensors (8 nmprecision)
• Contactless,voice-coilmotors (<55mW,1mmstroke,,± 0.24Nand0.08Nforflat)
• Lowprint-through gluedmagnet(19acts)
• Thinglassshell(400mmdiamx1mmth.,F/6)
• 1singlecable,1smallelectronicsbox(15W)(providing localcontrol loopandlaunchsafetymechanism forthethinshell)
400mm
Fromadaptivesecondariestoaspaceactiveprimary
LBT:ellipt.1m,672acts,kW,1kHzVLT:asph.1.2m,1170acts,kW,1kHz
LATT:spher.0.4m,19acts,1W,1Hz&newhaircap,tonsurton
?
Solutionsvalidated,towards TRL5
• Shellelectrostatic locking:Theshell is electrically ‘glued’ontheRefBodyduring launch
• Goaloptical quality
• Reduced power consumptionContactless,voice-coilmotors(<55mW,1mmstroke)Low bandwith smartactuators
Solutionsvalidated,towards TRL5
• Shellelectrostatic locking:Theshell is electrically ‘glued’ontheRefBodyduring launch
• Goaloptical quality
• Reduced power consumptionContactless,voice-coilmotors(<55mW,1mmstroke)Low bandwith smartactuators
Solutionsvalidated,towards TRL5
• Shellelectrostatic locking:Theshell is electrically ‘glued’ontheRefBodyduring launch
• Stability checked• Comparablewithground
based technology:flattened 30nmRMSWFE
• Goaloptical quality
• Reduced power consumptionContactless,voice-coilmotors(<55mW,1mmstroke)Low bandwith smartactuators
LATT- integration
Actuatorcupsmountedonthealuminumhoneycomb
Referencebodyfrontsurfacewithcapacitivesensor
Actuatormagnetsgluedontheshell Shellmountedonthereferencebody
Laboratorytestcampaign
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Vibrationtest
ThermaltestThermo-vacuumtest
Electrostaticlockingtest
lockingpressure:600N/m2
Opticaltest
WFEcomparablewithAOafterremovingthemembranesdeformation(λ/6 @UV)
Maxacceler.:10g
Temperaturerange:-25°Cà55°CTested@1e-5mbar
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• @sameopticalarea:• Largeractuatordensityisfeasible (nooptical
compression)• Lowerprint-through (dispersedonlargerarea)
• @sameactuatordensity:• Largercorrectionrange (lower localstiffness:pvs p’)• Lowerpower-budget (lowerlocalstiffness)
• Easiermanufacturing,nominiaturization
p
p’
LATTscaling:fromsecondary toprimary
14 ESTEC/ContractNo.22321/09/NL/RA
• 2in1:activeelement+lightweight<22kg/m2
• lowarealdensitycomparedtoexistingsystems• noneedtodevelopnovellightweighttechnologies• Norelay,noadditionaloptics,simpledesign
• Verylowpowerconsumption• <55mwforeachact• 15Wforcontrolelectronics
• Naturalsolutionforsegmentedmirrors• Alignment+phasingallocatedtoactiveoptics• Actstroke&accuracyrelaxdeploymenttolerances• Complexmirrortopology:localcorrectionis easier
WhyaLATT-likeprimarymirrorisattractive
Conclusion• Thinshell+voicecoilacts+capac.sensors:wellestablishedtechnologyforAOmirrors
• LATT:• Sphericalprimarymirror,40cm diam,F/6• 19acts,55mW/act• CFRP+ALhoneycomb+thinzerodurshell:<22kg/m2
• LATTdemonstrateditsapplicabilitytospace:• lightweightshell launchstresses• Lowpowerbudget shellcontrollability
• LATTdemonstratedtheconceptof:• Active+lightweight spaceprimary(2in1)• Suitabletosegmented/deployablesystems
LATTOBB:40cm,19acts
1m,7segments
1m,monolithic3-5m,segmented
LATT:abrickformorecomplexsystems