ContinuingtheLegacyoftheHubbleSpaceTelescopeAdvanced Technology Large-Aperture Space Telescope

(ATLAST)-AKA-

The Large UV/Optical/IR Observatory (LUVOIR)

The ATLAST Study TeamJuly 9, 2015

CONCEPT OVERVIEW• A four-institution design study of a 10-m class UVOIR observatory

• Detailed conceptual engineering design studies traceable to science goals• Identification of technology priorities and requirements• Room temperature telescope avoids complex cryogenic design and I&T • Serviceable and upgradable, also allows ready access during I&T

• Better together: concept provides for both exo-earth survey/characterization and for cutting-edge general astrophysics, as recommended by• Enduring Quests, Daring Visions (NASA 30-Year Roadmap, 2014)• From Cosmic Birth to Living Earths (AURA report, 2015)

Public release at AMNH on July 6

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The Advanced Technology Large-Aperture Space Telescope (ATLAST)

The Next Great Leap In AstrophysicsBreakthrough in UVOIR Resolution and

Sensitivity throughout the Universe

Resolve 100 pc Star-Forming Regions Everywhere in the Universe

Tracing the History of Star Formation in all Types of Galaxies up to 10 Mpc

Identification of Habitable Zone Planets and detection of Biosignatures

The ATLAST Reference DesignThisATLASTreferencedesignisa9.2-mobservatoryunderassessmentasacandidateforselectionbythe2020DecadalSurvey.Itisdesignedtobeapowerfulgeneral-purposenon-cryogenicobservatoryoperatingfrom0.1μmto1.8+μmandabletosearchforbiomarkersinthespectraofcandidateexoEarthsintheSolarneighborhood.

Engineering Progress: IStarlightsuppressionviacoronagraph• Coronagraph

o Multipleconceptsforsegmentedmirrorcoronagraphsinearlydevelopmentstages(e.g.Guyon,PueyoandLyon)

o Phase-OccultedNullercouldreducerequirementsonsystemdynamicstabilitysinceitinterferestelescopepupilagainstitselfviarotationalshearing

o Starshadecouldbeemployedinsecond generationforspectroscopicfollowup

InterfaceDevelopment:• BoundingInstrumentInterfaces

o Initiatingstudyofobservatoryconstraintsoninstrumentcomplemento Mass,power,thermal,physicalvolume,maxdatarateandvolume,etc.

• SLSandATLASTSynergyo Engineer-to-engineerconceptualinterfacedevelopmentmeetingsongoingo MeetingsheldinDecember2014andMay2015

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Engineering Progress: II

DynamicStability• Boundinganalysisviaintegratedmodelingindicates

feasibilityforachieving10 pmoverareasonablebandpassofreactionwheelspeedswithastateoftheartnon-contactisolationsystem

ThermalStability• Goalof<5pmanalyticallydemonstratedwith

1mKcontrolfromrear-sideradiativeheaterplatewithouttakingadvantageoftimevariationo AnalysisbasedonrealizableULEorSICmirrors

leveragingexistingmirrorsandrealradialCTEdata

5MMSD Lightweight ULE

Segment Substrate (GSFC/MSFC)

Key Technical Tall Poles: I• Starlightsuppressionrequirescontrastat10-10. Keycontributorsare:

• Coronagraph:SignificantongoinginvestmentinstarlightsuppressionviaSTMD,WFIRSTandSATprograms.

• Telescope:Primarymirrorthermalstabilityandbackplanestructureo Mirrorsegments:<5pmanalyticallydemonstratedwith1mKcontrolo Telescopesupportstructure

• Slowinstabilitiescanbeactivelycontrolled,although high-speedmotionshavetobeisolated

• Ultrastable,low-massstructuresrequiretechnologyinvestment• Complementsinvestmentsbeingmadeinstarlightsuppressionand

isolationsystems• Ultrastablelow-massstructures

• Designof~zeroCTEcompositestructureshastoaddressthreeissues:o Temporalinstability:o Singleevents(micro-lurches):occurswheneverstressstatechangeso Moisturedesorption:

• Solutionistomaturenano-particlecompositetechnologyo Materialisalreadyincommercialuse

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Key Technical Tall Poles • Newtechnologycompositestructureswillhavetobetestedtopmlevels

• Requiresnewmetrologyapproachandsubscaletestbed• BuildupondynamictestingatnmlevelonJWSTmirrorsegments

• ATLASThasassembledatelescopestructuresteam• BallAerospace,Orbital ATK,GSFC,JPL&MSFC

• DevelopmentGoals:• Demonstrateanultra-stablenano-compositestructureandtheassociatedactuator

andhexapodmountneededforasegmentedtelescopewithpicometerclassdynamicstability

• Buildabreakthroughhigh-speedspeckleinterferometercapableof<50picometer-classspatialdynamicmeasurementsofanultra-stablecompositestructureandmirrorsystemalongwithalasermetrologysystemformeasuringmotions

• Developanultra-stablespatialdynamicstestbedformodelvalidationtothepicometerlevelthatwillboundandcharacterizethepicometerscalenon-linearities

• Ultrastablestructureshavecross-cuttingapplications• Otherastrophysicsmissions: e.g., gravitywavedetection• Opticalcommunications 7

W

ATLAST9.2mScalableArchitecture

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36 JWST-Size Segments(Glass or SiC, Heater Plates) Actively controlled SM

6-dof control metrology to SI

• Telescope Isolated from SC• 6-DOF magnetic isolation• Signal & Power fully isolated

Deployed Baffle

Serviceable Instrumentsare externally accessible

• 3-layer sunshield, • Constant angle to sun ➡ stable sink• Sunshield deployed using 4 booms

• Pointing gimbal maintains constant sun angle

• Single pointing axis

Stowed

ATLAST Gimbal DeploymentThisCADdrawingsequencedepictstherotationofthesciencepayloadfromits

stowedpositiontodeploymentintoitsscience-pointingconfiguration.

ATLASTReferenceDesignLeveragesExistingJWSTDeploymentforLargeAperture

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2009 (First ATLAST Studies)Assumed Larger EELV was Under Development

Note: JWST-Type Wings

2013 Circular GeometryDelta IVH

Design reference mission builds upon existing investments in JWST to manage overall cost and is

scalable to larger aperture sizes.

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Parameter Requirement Stretch Goal

Primary Mirror Aperture ≥ 8 meters 12 meters

Telescope Temperature 273 K – 293 K -

Wavelength Coverage

UV 100 nm – 300 nm 90 nm – 300 nmVis 300 nm – 950 nm -NIR 950 nm – 1.8 µm 950 nm – 2.5 µm

MIR - Capability Under Evaluation

Image QualityUV < 0.20 arcsec

at 150 nm -

Vis/NIR/MIR Diffraction-limited at 500 nm -

Stray Light Zodi-limited between 400 nm – 1.8 µm -

Wavefront Error Stability (for Exoplanet Science)

< 10 pm RMS uncorrected WFE per control step -

Pointing ≤ 1 milli-arcsec -

Telescope Design Parameters

ManagingthePerceptionThe ATLAST/LUVOIR reference concept is designed to be substantially less costly than simple extrapolation from, for example, the cost of JWST. For example . . .

• Unlike JWST, ATLAST/LUVOIR is non-cryogenic, thus obviating complex thermal design, technologies, and I&T

• ATLAST/LUVOIR builds upon designs, personnel, ground support equipment, facilities, and experience with JWST and other segmented optical systems

• ATLAST/LUVOIR team is identifying technology tall poles and advocating early funding of them

• ATLAST/LUVOIR, working with senior NASA managers, have identified management strategies that have been demonstrated opportunities to manage cost and schedule growth.

• Compatibility with multiple launch vehicles manages risk and associated costs: Delta IV Heavy, SLS (5,8.4,10m fairings), Falcon Heavy

Takeaway: I• Studyjustenteringitsthirdyearwiththreepriorityelements:

o Developanaffordablelarge-apertureconceptualdesignforabroadlycapableUVOIRobservatory

o Identifyandinvestinthematurationofprioritytechnologyinvestmentstoreadythedesignforselectionintheearly2020s

o EstablishthemostcompellingsciencegoalsforamissionthatwillcontinuetheheritageofHST

• Largeapertureobservatorycontinuestoberecommendedashighpriority• EnduringQuests,DaringVisions(NASA30-yearastrophysicsroadmap,2014)• TheAssociatedUniversityforResearchinAstronomy(AURA)report

FromCosmicBirthtoLivingEarths reportidentifiedaUVOIRmissionverysimilartoATLAST.

⇒KillerappwillbethecapabilitytosearchforthespectroscopicsignaturesofbiologicalactivityintheatmospheresofhypotheticalEarth-likeworldsinthesolarneighborhood:AreWeAlone?

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Takeaway: II• ATLASThasidentifiedkeytechnologiesandneedforearlyinvestment

• Significantinvestmentincoronagraphtechnologyalreadyunderway

• ProposeSTMDinvestmentinremainingtall-pole:ultrastablestructures

• Demonstrateultra-stablenano-compositestructure

• Buildinterferometercapableof<50pmdynamicmeasurements

• Developanultra-stablespatialdynamicstestbedformodelvalidationincludinglasermetrology

• Initialinvestmentof$900 k(detailedcostingisavailable)

• FirststepwouldbereleaseofanRFIbyGSFCforindustryinterest- Industrywouldliketoparticipate,andisthemainsourceofrecentadvancesinmaterialsforultrastablestructures

• Cross-cuttingtechnologywithapplicationsingravity-wavemissions

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“FLYAROUND”VIDEOHERE

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BACKUP:TECHNOLOGYROADMAPOVERVIEW

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InternalCoronagraph Need Capability Current

TRLEnabling/Enhancing

Technology,Engineering,orManufacturing

SegmentedAperture,High-Contrast,BroadbandCoronagraph(IncludesallWavefrontSensing&

ControlDevelopment)

1x10-10 rawcontrastIWA2λ/DOWA64λ/D400nm– 1.0µm200nm– 1.8µm(goal)SegmentedPupil

1.3x10-9 between3-16λ/D720nm– 880nmUnobscured

5.7x10-9 between1.5-2.5λ/DmonochromaticSegmentedDM

3 Enabling Technology

DeformableMirrors128x128continuousDMElectronics/harnesses,etcEnvironmentallyrobust

64x64continuousDMWire-dense,singlepointfailureharnesses,etc.

3 Enabling Engineering,Manufacturing

AutonomousOnboardComputation

Closed-loopcontrolRad-hard,lowpower

Human-in-the-loop(JWST)Ground-baseddesktopCPUs/GPUs

3 Enabling Technology

ImageProcessing&SpectraExtractionAlgorithms

(IncludingPSFCalibration)

Factorof50-100ximprovementinPSFcalibration

25xdemonstrated30xgoalforWFIRST-AFTA 3 Enabling Engineering

High-ContrastIntegralFieldSpectrometerInstrument

DevelopmentTBD TBD TBD Enabling TBD

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Starshade Need Capability CurrentTRL

Enabling/Enhancin

g

Technology,Engineering,orManufacturing

StarshadeEdgeScatter Edgeradius≤1µmReflectivity<10% Edgeradius>10µm TBD TBD Technology

FormationFlight&Guidance,Navigation&Control

Lateralsensingerr≤20cmControlpeak-to-peak1m TBD TBD TBD Engineering

Petal&TrussConstruction&Deployment

Demonstrationofpetal&trussconstructionanddeploymentforATLAST-sizedstarshade

Petalprototypefor40-mclassstarshademeetsfabricationtols.12-mAstromeshdeploymentongroundtotols.with4petals

TBD TBD Engineering,Manufacturing

StarshadeContrastPerformance&ModelValidation

Contrastvalidationwithflight-likeFresnelnumbers(≤50)Modelvalidationofcontrastperformance

ExperimentalcontrastsatFresnelnumberof∼500Modelsnotyetcorrelatedto10-10 level

TBD TBD Technology

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Ultra-Stable,LargeApertureTelescopes

Need Capability CurrentTRL

Enabling/Enhancing

Technology,Engineering,

orManufacturing

ThermalControlSystem 10nm/Kstability0.01mKcontrolaccuracy

100nm/Kstability1mKcontrolaccuracy 3 Enabling Technology

StableStructures LowCTE,micro-lurchcharacteristics

CTETBDExperiencemico-lurchatinterfaces

3 Enabling Technology

Mirrors(SurfaceFigure,ArealDensity,Cost,ProductionRate)

<7nmRMSfigure<36kg/m2 (DeltaIV)<$1M/m2

30-50m2/year

∼ 7nmRMS(HST,ULE)70kg/m2 (JWST)$6M/m2 (JWST)4m2/year(JWST)

4 Enabling Engineering,Manufacturing

DisturbanceIsolation&DampingSystems

140dBisolation>40Hz

80dB>40Hz(JWSTpassive)DisturbanceFreePayloadatTRL5with70dB

4 Enabling Technology

Metrology&Actuators 1pmaccuracy(metrology)1pmaccuracy(actuators)

1nmaccuracy(metrology)5nmaccuracy(actuators) 3 Enabling Technology

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Detectors Need Capability CurrentTRL

Enabling/Enhancing

Technology,Engineering,orManufacturing

UVPhoton-CountingDetectorsForExoplanetImaging&

Characterization

200nm– 300nmReadnoise<<1e−Darkcur.<0.001e−/pix/sRadhard;5yearlifetimeVisibleblind

GaN-basedEBCMOSNeedslifetimetests

Micro-channelplatesNotroomtemperatureLimitedlifetime

5 Enhancing Technology

Large-FormatHigh-SensitivityUVDetectorsforGeneral

Astrophysics

100nm– 300nm(90nm– 300nmgoal)70%q.e.>2kx2kformatRadhardVisibleblind

δ-dopedEMCCD:50%q.e.(100nm-300nm)1kx1kformatNotvisibleblindNotradhardOperationat-120C

4 Enhancing Technology

Vis/NIRPhoton-CountingDetectorsforExoplanetImaging

&Characterization

400nm– 1.0µm(1.8µmgoal)Readnoise<<1e−Darkcur.<0.001e−/pix/sRadhard,5yearlifetime

EMCCD:NotprovenradhardDarkcur.maynotbelowHardcutoffat1.1µm

HgCdTeAPD:Darkcur.toohigh

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4Enabling Technology

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MirrorCoatings Need Capability CurrentTRL

Enabling/Enhancing

Technology,Engineering,orManufacturing

UVCoatingReflectivity>70%90nm– 120nm>90%120nm– 300nm>90%300nm– 3.0µm

<50%90nm– 120nm80%120nm– 300nm>90%300nm– 3.0µm

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EnablingEnhancingEnhancing

Technology

UVCoatingUniformity <1%atλ ≥90nmTBD90nm– 120nm>2%120nm– 250nm1-2%300nm– 3.0µm

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Enhancing Engineering

UVCoatingPolarization <1%atλ ≥90nm Notyetassessed;needsstudy. 2 Enhancing Engineering

CoatingEnvironmentalDurability

Easytouse,reliableautomatedFUVcharacterizationisneededfortestingandcrossverification.

Stableperformanceoverayearhavebeenmade,thoughperformancebelow200nmislow.

3 Enabling Engineering