Pasadena, California October 24-25, 2007

TMT M1 Segment Support Assembly (SSA) Preliminary Design Review (PDR) Volume-1: OVERVIEW
Pasadena, California October 24-25, 2007 Contributors to the development effort: from IMTEC RJ Ponchione, Eric Ponslet, Shahriar Setoodeh, Vince Stephens, Alan Tubb, Eric Williams from the TMT Project George Angeli, Curt Baffes, Doug MacMynowski, Terry Mast, Jerry Nelson, Ben Platt, Lennon Rodgers, Mark Sirota, Gary Sanders, Larry Stepp, Kei Szeto TMT Confidential The Information herein contains Cost Estimates and Business Strategies Proprietary to the TMT Project and may be used by the recipient only for the purpose of performing a confidential internal review of the TMT Construction Proposal. Disclosure outside of the TMT Project and its External Advisory Panel is subject to the prior written approval of the TMT Project Manager. * Note: HYTEC, Inc. merged with IMTEC Inc. in March 2007. TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 1

HPS-280001-0105 – Volume 1 – October 24-25 2007 – Slide 2
Outline Volume-1: Overview Thirty Meter Telescope Overview SSA Project Overview Key Design Requirements Design Concept SSA Preliminary Design Key Subsystems Axial Support Lateral Support Tower, Guide Flexure, Locks, Registration Warping Harness Subcell Volume-2: System Level Calculations M1 Segmentation Segmentation Correction (for Variable Segment Geometry) Budgets: Installation & Alignment Edge Gap Actuator Stroke Mass TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 2

Outline Volume-3: System-Level Finite Element Analysis Model Description Optical Performance Stiffness and Modes Buckling Sensitivity Analyses Stress Analysis Backup Slides Volume-4: Warping Harness Design and Analysis Fundamental Approach & Architecture Warping Harness Requirements Opto-mechanical Mechanical Design Concept Performance Analysis Actuator arrangement Surface correction Derived Requirements for Components Mechanical & Electrical Design Quantization Error Estimate TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 3

Outline Volume-5: Flexure Design and Analysis Design Load Combinations Central Diaphragm Rod-Type Flexures Lateral Guide Flexure Volume-6: Subcell Integration & Segment Handling Subcell Integration & Alignment Fixed Frame Installation Dummy Mass Subcell Alignment Segment Lifting Jack & Lifting Talon Jack design Lifting Talon design Volume-7: Summary and Future Plans Prototype Testing Test Plans Component testing Full Prototype testing Schedule Summary Where we are and where we’re going Technical Risks Conclusions TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 4

Thirty Meter Telescope
BRIEF TELESCOPE OVERVIEW TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 5

M1 Array 30m Diameter ~60m ROC 492 Segments 1.44m x 45mm1 PSA On Mirror Cell Note 1) 45mm for Glass-Ceramic, 50mm for Fused Silica TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 6

Segment Size Nominal Segment size is 1.44 m across vertices Limited by blank size to maintain several competitive suppliers Thickness: 45 mm if glass ceramic 50 mm if fused silica (ULE) Aperture limits: Outermost corners: 15.0 m radius Innermost corners: m radius 1.44 30m diameter 15.0 1.45 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 7

M1 Parameters Fundamental M1 Parameters: Constant-gap segmentation: 82 different segment shapes Six identical sectors Nominal segment: 1.44m regular hexagonal meniscus Glass-Ceramic, 45mm thick 60m paraxial radius of curvature Neglect asphericity in support design activities Average segment ROC ~62.5m Assume worst case CTE = ppm/°C in analyses Alternate segment: Fused Silica, 50mm thick meniscus SSA can be re-tuned to accommodate XPSA YPSA ZPSA SSA Base Cell Truss 1.44 m 45 mm TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 8

M1 Parameters Segmentation Pattern: Sector Boundary - Note Fixed Frame Clocking 60◦ View from Sky TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 9

Thirty Meter Telescope
SSA PROJECT OVERVIEW TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 10

SSA Project Scope IMTEC Design/Development Responsibilities Include: Segment Support Assembly (SSA) Segment Lifting Jack Segment Lifting Talon Attaches Mounted Segment Assembly (MSA) to Segment Handling Crane Subcell Integration Hardware: Mass Simulator Surveying Target Holders Subcell Alignment Tooling Release Prototype Drawings Build, Test and Deliver Prototypes Refine design for production Propagate design to 82 versions (segmentation effects) TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 11

Mounted Segment Assembly (MSA) Polished Mirror Assembly (PMA)
SSA Overview PRIMARY SEGMENT ASSEMBLY (PSA) Mounted Segment Assembly (MSA) Subcell Actuator1 Produced at Optics Shop IMTEC Responsibility Polished Mirror Assembly (PMA) Optical Coating Fixed Frame Assembly (1 ea) Adjustable Alignment Positioners (AAPs, 3 ea) Actuator Flexure (3 ea) IMTEC Responsibility Edge Sensors1 (6-drive, 6-sense) Polished Mirror Segment Segment Support Central Diaphragm (1 ea.) Moving Assembly (1 ea.) Cables & Connectors for Sensor1 & WH --Whiffletrees (3 ea) --Moving Frame Assembly (1 ea) --Warping Harness Actuators (21 ea) --Lateral Guide Flexure (1 ea) --Tower Assembly (1 ea) --Lock Assemblies (3 ea) --Sheet Flexures (6 ea) Electrical Bulkhead Panel Assembly Comprises the SSA Removed for Re-coating 1) In WBS, Actuator is part of the M1CS not M1Optics TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 12

SSA Overview PSA ATTACHED TO MIRROR CELL Include Subcell + Actuators
Polished Mirror Assembly (PMA) Add Segment Support Primary Segment Assembly (PSA) Polished Mirror Segment Add Optical Coating, Edge Sensors, Sensor & WH Cabling & Connectors Mounted Segment Assembly (MSA) TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 13

SSA Overview SEGMENT SUPPORT ASSEMBLY (SSA) TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 14

KEY DESIGN REQUIREMENTS
TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 15

Key Requirements (1/4) SSA-Induced Surface Errors: Goal: Minimize gravity and thermal distortion while controlling cost Optical performance of SSA evaluated by system level PSS analysis Performed by Project and JPL using IMTEC unit case predictions as inputs When complete, analysis to consider all SSA distortion effects: Gravity, Thermal Distortion, Thermal Clocking, Polishing, Mfg, + … Assumptions: Observing segment-zenith angle: -15° to +80° → max Δς = 80° 0° to 65° telescope Zenith ± 15° from M1 curvature Observing temperature: 9°C (TSITE) ± 4°C Based on Armazones site testing data (80% of observing time within +/-4C) Alignment & Phasing System (APS) + Warping Harness used regularly to null DC errors - Seasonal mean temperature offset, Tmean - Difference between optics shop figuring temp and Tref Single Support-System design, customized for each segment type: Accommodate shape variations from M1 segmentation (up to 0.5%) No backlash or stick-slip: Flexure-based mechanisms TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 16

Key Requirements (2/4) Accommodate ± 2.5mm actuator stroke: SSA hard stops nominally at ±3.0mm Survive full differential tip/tilt Remote-controlled warping harness: Control 2nd and 3rd order Zernikes: Correction capability: 200 to 2100 nm P-V (38 to 410 nm RMS) Improvement ratio (RMS before correction / RMS after correction) > 15 on 2nd order terms: focus & astigmatism > 5 on 3rd order terms: coma & trefoil Periodic Adjustment: Capability to readjust up to 10 times per night (~1/hour), if necessary Power dissipation <2 Watts/segment Includes all segment heat sources (Actuators, sensors, electronics, etc.) 50 years lifetime; high reliability: Only significant wear items are warping harness moment actuators 6-DOF adjustable Subcell & repeatable registration system: Correct for Mirror Cell tolerances ( ± 5 mm adjustment range, set-and-forget) Removal/replacement of SSA with ± 50 μm repeatability TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 17

Key Requirements (3/4) SSA mass < 90 kg (moving mass < 45 kg) Not including actuators, segment, edge sensors & cables for edge sensors Ref: Segment mass ~153 kg for glass ceramic Static stiffness > 12 N/μm, piston: Assuming rigid actuator & mirror cell Natural frequencies of PSA > 35 Hz with 10N/mm actuator stiffness: Avoid rotating machinery disturbances at ~25 and ~30 Hz 50 or 60 Hz AC power grids possible Permit higher actuator control bandwidth EXCEPT: Torsional modes permitted to be <35 Hz Unlikely to be excited on telescope fn >8 Hz required for static stiffness Environments: Operating conditions such as temperatures, g-levels, etc summary slide to follow TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 18

Key Requirements (4/4) MSA shall be compatible with Coating Chamber requirements TBC: Cleanliness, Outgassing and Coating process compatibility SSA design shall be designed for manufacture 492 units + Spares allows for economies of scale if the design is sound Maintainability and Servicing considerations Segment exchanges are frequent and must be straightforward Recoating every 2 years implies 5 segment exchanges per week on average Cost control is fundamental to the design Cost of manufacture and test Cost of ownership Reliability Maintainability TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 19

Environments Quantity Observing3 Non-obs.3 Survival3 Handling Transport Recoating Segment Zenith angle1 (+Z to vert.) 0 to 80° 0 to 105° 0 to 135° 180° Temp. and rate of change 0 ± 5°C ± 3°C/hr -15 to 35°C -20 to 40°C -20 to 50°C ≤ 50 °C Humidity 0 to 95% 0 to 100% 0 to 100% condensing - Wind force2 4.18N RMS TBC4 8.35N RMS Wind moment1 1.44Nm RMS TBC5 1.44Nm RMS TBC5 2.88Nm RMS TBC5 Quasi-static load6 1g 1.4g 3.0g, any axis TBC 10g, any axis Altitude m 0-5000m m Tracking and slewing rates El <0.039°/s Az <2.26°/s TBD Tracking and slewing accel. El <.00015°/s2 Az <.00880°/s2 El <2.0°/s2 Az <2.0°/s2 1. About any axis in local x-ySSA plane 2. In local zSSA direction (piston) 3. SSA on telescope 4. Scaled up from 1.2m segment loads by a2 5. Scaled up from 1.2m segment loads by a3 6. All dynamic loads treated as quasi-static. 1g dead weight not additional TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 20

SSA Design DESIGN CONCEPT TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 21

Key Functions of SSA Support segment with minimum distortion (observation mode): Relative to reference state (as figured) ςSEG = 0°, TREF Ability to position segment in 3 DOFs (piston, tip, tilt): Continuous, active positioning by three linear actuators Ability to alter surface shape to correct for figuring errors and other effects: Occasional correction Interface with Mirror Cell Provide means to align SSA in 6 DOFs: Compensate for mirror cell fabrication tolerances (+/- 5mm any direction TBC] One-time adjustment during telescope integration Ability to remove and replace MSA with specified repeatability: Quick replacement of segments without re-alignment of Subcell Accommodate irregular/variable size segments with single support design: Uniform gaps lead to irregular and/or variable size hexagons Provide means to extract segment out of M1 array for re-coating/maintenance: Lifting jack Segment Lifting Talon Interface with segment removal crane TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 22

Mounted Segment Assembly (MSA)
Design Concept Final Figuring Polished Mirror Segment Cam Locks (3ea) Diaphragm 3 ea Whiffletree Axial Support Rod Flexures Guide Flexure Edge Sensors (12) Warping Harness Actuators, 21ea Moving Frame Tower Mounted Segment Assembly (MSA) Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 23

Design Concept 3ea Adjustable Alignment Positioners (AAPs) Actuator flexure Actuator Output Shaft Mirror Cell Fixed Frame 3ea Actuators SUBCELL+ACTUATORS TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 24

Design Concept Lifting Talon Segment Lifting Jack MSA Placed on Jack TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 25

MSA Attached to Subcell
Design Concept Actuator Flexure Clamped to Moving Frame (3 places) MSA Attached to Subcell TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 26

PSA Operational Configuration
Design Concept Cam Locks Released Mirror Segment Diaphragm 3 ea Whiffletree Guide Flexure Axial Support Rod Flexures Warping Harness Actuators, 21ea Moving Frame Tower Fixed Frame Mirror Cell 3ea Adjustable Cell Interface MSA hold-down bolts 3ea Actuators PSA Operational Configuration TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 27

SSA Design PRELIMINARY DESIGN TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 28

Design Status Segmentation scheme has been chosen: Scaling rule selected to minimize blank diameter We have a detailed 1.44m Preliminary Design: 27-point mechanical whiffletree axial support Central diaphragm lateral support 21-actuator/segment, whiffletree-based warping harness Correction for segment shape variations via custom WT joint locations Repeatable interface, Subcell alignment, and actuator attachment Extensive, coupled performance modeling has been performed: Complete FEA revision to reflect Preliminary Design is complete Design satisfies nearly all requirements Completing final changes required for Prototype SSA fabrication Hardware designs being detailed: Detailed drawings for prototype in process TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 29

Current PSA Design PSA attached to mirror cell: Mirror Cell Actuator TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 30

Flexures Bonded to Segment
Central Diaphragm (bonded to segment) Edge Sensor 12 ea. Alignment Arrow Points to center of M1 Axial flexure assemblies 27 ea. bonded to segment Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 31

Small Whiffletree Triangles Attached
- 3 inner - 6 outer Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 32

Large Whiffletree Triangles Attached
Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 33

Sheet Flexures Added Sheet flexure, 6ea In-plane connection between Whiffletree Triangles and Moving Frame Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 34

Moving Frame Attached V-Groove for lifting, 3 ea. Sheet flexure, 6ea In-plane connection between Whiffletree Triangles and Moving Frame Moving frame Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 35

Warping Harness Added Warping harness leaf-spring Warping harness actuator Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 36

Tower & Locks Installed
Tower Assembly with Repeatable Interface Electrical Connector Bulkhead Panel Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 37

Fixed Frame Included Fixed Frame Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 38

Installed on Mirror Cell
Actuator flexure Actuator Mirror Cell Adjustable Alignment Positioner (AAP) Note: Does not represent assembly sequence TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 39

Sector Boundary PSA’s Clocked 60 degrees between sectors Two fixed frame versions Sufficient clearance at boundary Adjacent actuators 35mm nominal clearance Sector-A Sector-F TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 40

Group of Segments View of Seven Adjacent Segments – Top View TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 41

Group of Segments View of Seven Adjacent Segments – Bottom View TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 42

SSA Design AXIAL SUPPORT SYSTEM TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 43

Axial Support System Two level, 27-point whiffletree system All-Aluminum design (nearly) Triangles and sheet flexures Aluminum Rod Flexures Stainless Steel Analysis shows high CTE of Aluminum to be acceptable Lower machining costs and corrosion resistance a plus Triangles nested for compactness Pivot Flexures at Moving Frame Connection Mirror Support Rod Flexures Rod Flexures at pivot locations TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 44

Axial Support System Whiffletrees Ride on Moving Frame Moving Frame: 6061 Aluminum weldment Pivot Flexure Actuator Rod Flexure Clamp Handling Feature TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 45

No further discussion of Sheet Flexures
Axial Support System Sheet Flexures: Concept introduced by SALT Stabilize whiffletrees in XYSSA plane Pivots (Kz) + Sheet Flexures (Kx, Ky, Rz) provide 4 Degrees of Stiffness Tip/Tilt (Rx & Ry) remain compliant Whiffletree mass is nominally balanced about sheet flexure plane Aluminum 7075-T651, 0.508mm (0.020”) thick Pivots 3 per WT Sheet Flexures 2 per WT Sheet Flexure Attachment to Moving Frame, Typical No further discussion of Sheet Flexures Questions? TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 46

Detailed discussion: PDR Volume-5
Axial Support System 27-Mirror support rod flexures Invar pucks bonded to mirror using 3M EA-2216 Epoxy Well characterized adhesive JPL heritage for Invar/Zerodur bonds (documented process ) 0.250mm nominal bondline (0.010”) Stainless Steel rods connect pucks to triangles 304V Cold drawn 94% CW 250 ksi yield strength Threaded end connections: Stiff, strong, adjustable & removable Bondline Mirror Vent Hole Invar Puck Flexure: 2.1mm OD x 143mm Long Vent Hole Small WT Triangle Detailed discussion: PDR Volume-5 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 47

No further discussion of Triangle design
Axial Support System 9-Small whiffletree triangles Extruded Aluminum: 6061 T6 Low cost ~$12 per extruded blank, in production qty. 3-Large load-spreader triangles Cast Aluminum (A356 T51) Lowest manufacturing cost Complex shapes & large size ideal for casting No further discussion of Triangle design Questions? TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 48

Axial Support System Optical Performance Whiffletree support points and pivot locations determined by optimization Pivot locations unique for each of the 82 segment types See PDR Volume-2 for details Axial support gravity print-thru: Figured out at ςseg=0 Springs-back as [1-cos(ςseg)] Surface error amplitude ~10 nm RMS (ςseg=90) See PDR Volume-3 for details TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 49

LATERAL SUPPORT SYSTEM
SSA Design LATERAL SUPPORT SYSTEM TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 50

Lateral Support System
Lateral Support Design Simple Flat Central Diaphragm Low cost Compact (space limited by 45mm thick mirror) no decoupling flexures Diaphragm material: Invar 36 (one piece) Baseline for optical performance analysis Prefer to use INOVAR from Imphy Alloys (Fr.) High purity, w/Low Carbon content Low CTE [~1/2 of regular Invar (0.65 PPM/C)] Better temporal stability Bonded directly to mirror: Adhesive: 3M EA-2216, 0.250mm bondline (0.010”) Diaphragm dimensions: Rim OD: 150 mm OD, Hub OD 60 mm Flexure region: OD 130mm, mm thick 10 mm wide outer rim bonded to glass Mirror Pocket: 156 mm by 25.5 mm deep Rim t=3mm Central hub t=8.5mm Flexure t=0.350mm Detailed discussions: PDR Volumes-3 & -5 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 51

Diaphragm: Cross-Section View Diaphragm Adhesive Bond: Diaphragm to Glass Mirror Segment Adhesive layer Moving Frame TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 52

Moving frame concept isolates diaphragm Makes operating diaphragm deflections small: High strength material not required Lateral Support gravity print-thru Lateral support gravity print-thru: Zero out at ςseg=0 Springs-back as [sin(ςseg)] Surface error amplitude ~12 nm RMS (ςseg=90) Diaphragm Attached to Moving Frame Detailed discussion: PDR Volume-3 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 53

Tower, Guide Flexure, Locks and Registration
SSA Design Tower, Guide Flexure, Locks and Registration TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 54

Tower & Guide Flexure Tower & Guide Flexure: Provide lateral load-path for SSA Connect Moving Frame to Subcell (Fixed Frame) Accommodate segment piston/tip/tilt Guide flexure details in PDR Volume-5 Tower assembly includes: ½ of the registration interface ½ of the SSA lock system Tower: 6061-T6 Aluminum weldment Guide Flexure Attached to Tower at OD Guide Flexure Attached to MF at ID Guide Flexure SSA Lock 3 ea. Moving Frame (MF) Registration 3 ea. at 120 deg Tower TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 55

Tower & Guide Flexure Attached to MF Guide Flexure Attached to Tower Mirror Segment Convolution for piston compliance Moving Frame Clearance hole for Mirror Support Rod Flexure TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 56

SSA Locks Locks: Three per SSA: Secure Moving Frame to Tower Permanently installed Enable safe handling, installation & removal Support segment during actuator change-out Latched by spring-plunger detent Hardened cam keyed to handle Hardened insert mounted in moving frame Cam Spring Plunger TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 57

No further discussion of Lock design
SSA Lock Positions Locked: Moving frame pushed to “Neutral” position Nominal Clearance mm MSA can be installed, removed and handled Actuator can be replaced Unlocked: Moving Frame and Tower not in contact Act as Piston/Tip/Tilt hard-stop Nominal clearance +/-3 mm SSA range of travel outside range of actuator hard stops (+/-2.5mm) Moving Frame No further discussion of Lock design Questions? Moving Frame TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 58

Registration Requirements & Goals Repeatability +/-0.050mm in-plane Stiff connection in all DOF Face-to-face axial registration with thru-bolt Strong, stiff and easy to dimensionally inspect Lateral registration features not in axial load path Sufficient strength to position segments at 14.5 deg inclination during installation 0.25g lateral load plus friction Cycles: Assume one Installation & Removal per year for 50 years (50 cycles) Implies a near-kinematic design Design concept: Set of 3 tangential and axial contacts, 120 deg apart Lateral registration features: Tapered pin in V-groove with small in-plane radial clearance when assembled Clearance allows Tower to move slightly in X,Y, & Clocking Axial registration features: Mating flat surfaces clamped by thru bolt Friction joint during operation TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 59

Registration Hardware
Registration mating sequence (typical deg) Tower Separated From Fixed Frame Tower Lowered to Fixed Frame Captive Bolt Tightened to Clamp Joint Conical Pin V-groove TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 60

Registration Tapered pin: Material: Ti 6Al-4V Annealed & Nitrided 120 ksi base metal TiN: Rc70 surface coating for galling resistance Insert ring: Material: 17-4 PH Condition H1025 145 ksi yield strength Contact stress Contact force 1009N 210 kg at 14.5 deg inclination with sliding friction coefficient of 0.5 60 ksi max subsurface von Mises stress FSy = 2.0 Result: Durable interface that will not Yield or Gall TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 61

No further discussion of Registration design
Pin-Insert clearance: Cost: Machine shop quote: $400/set, in quantity No further discussion of Registration design Questions? TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 62

WARPING HARNESS SYSTEM
SSA Design WARPING HARNESS SYSTEM PDR Volume-4 Dedicated to Design and Analysis of Warping Harness TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 63

Warping Harness Approach & Architecture
Purpose: Allow automated periodic correction of low order surface distortions: Residual errors from polishing Coating stress distortion Seasonal mean-value of thermal distortion Segment positioning errors within the array (Focus and Astigmatism) etc. Fundamental Approach: Extension of the Keck design Re-figure the mirror by bending it in a controlled manner using whiffletree Bending moments introduced into whiffletree by a set of moment actuators Actuators are motorized, instrumented and tied into the M1CS Architecture: 21 whiffletree joints are fitted with moment-actuators Lead screw pushes against an instrumented leaf-spring to create a moment Stepper motor drives lead screw to permit automation TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 64

Design Concept Actuator Schematic
Stepper motor driven screw displaces end of leaf-spring Strain gauge on leaf-spring provides feedback for motor control Motors will be mounted on the large whiffletree triangles and to the moving frame Axial Support Flexure Small Whiffletree Triangle Small Whiffletree Triangle Nut Screw Large Triangle WT Joint Flexure (sheet flexure not shown) Stepper Motor Strain Gauge Leaf-spring TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 65

Optical Performance Analysis
Actuator Layout 21 Actuators Mx’’ & My’’ Large Triangles, 3ea (Only Mq required) Mx’ & My’ Outer Triangles, 6ea Mq, Inner Triangles, 3ea (Mr not required) Indicates Applied Moments (Equal and Opposite) TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 66

Optical Performance Analysis
Actuator Layout 21 Actuators integrated into axial support system Leaf Spring (Typ.) Actuator (Typ.) TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 67

SSA Design SUBCELL Fixed Frame AAPs Actuator Flexure TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 68

Subcell Design Fixed Frame Provides a stiff, stable interface between MSA and Mirror Cell Construction: Welded 6061-T6 Aluminum (2 versions due to segmentation) Interfaces: Mirror cell (via AAPs) MSA (via tower registration features) Actuators (bolted and pinned joints at ends of Fixed Frame) Segment lifting jack (at center post) See PDR Volume 6 for details Deep cross-section required to meet 35 Hz for Lateral mode Optimized to reduce mass Fixed Frame AAP Actuator Attachment NEXT SLIDE TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 69

AAP Design AAP Requirements/Features Range of Travel
+/-8mm adjustment in-plane Mirror Cell mfg. tolerances (5mm) plus segmentation effects (3mm) +/-5mm vertical adjustment Aligned one time during construction and permanently locked/pinned Jam nuts and match-drilled dowel pins Smooth adjustment (resolution) 30mm post diameter required for stiffness 35 Hz lateral mode Welded Stainless Steel Post bolted to Mirror Cell Brass Spherical Nuts Stainless Steel Spherical Washers Special tools required to torque assy. Dowel Pins Match drilled at assy. 2 ea. Threaded Post: bolted to truss Spherical Washer 2ea. Spherical Nut 2ea. Lock Nut 2ea. Cross Section of AAP Fixed Frame integration discussed in PDR Volume-6 Alignment budget discussed in PDR Volume-2 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 70

Subcell Design Fixed Frame (Top plate removed) Jack Center Shaft Support and Bushings See PDR Volume-6 for Jack Design Registration Pins 3 ea. Tower Clocking Pin See PDR Volume-6 Jack Center Shaft Guide & Retention Pin See PDR Volume-6 AAP attach hole Actuator Attachment Castings Holes for surveying target holders 3ea. See PDR Volume-6 TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 71

Actuator Flexure Design Overview Actuator Rod Flexure Design – See PDR Volume-5 for Details Knurled Flexible Region: 7.23mm OD x 115mm Long TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 72

Summary: Just Presented: M1 Overview SSA Project Overview Key Requirements Subsystem Designs Additional Presentations to Follow: Volume-2: System Level Calculations Volume-3: System-Level Finite Element Analysis Volume-4: Warping Harness Design and Analysis Volume-5: Flexure Design and Analysis Volume-6: Handling and Integration Volume-7: Summary and Future Plans Additional Comments & Questions? TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 73

Acknowledgements Acknowledgements: The TMT Project gratefully acknowledges the support of the TMT partner institutions. They are the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology and the University of California. This work was supported as well by the Gordon and Betty Moore Foundation, the Canada Foundation for Innovation, the Ontario Ministry of Research and Innovation, the National Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the British Columbia Knowledge Development Fund, the Association of Universities for Research in Astronomy (AURA) and the U.S. National Science Foundation. TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 74

BACKUP SLIDES TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 75

SSA Materials Material Properties for Key Components TMT.OPT.PRE REL01 HPS – Volume 1 – October – Slide 76

Pasadena, California October 24-25, 2007

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