ATST Telescope Mount Assembly

1. ATSTTelescopeMountAssembly

2. TMA Systems Design ReviewTopics of Discussion Overview & Charge to Committee (Mark) 6 Major Parts of SDR: SRD Flow-down & Error Budgets (Rob Hubbard) Specifications (Mark) Reference Designs (Bret Goodrich, Mark) Lunch Performance & Analyses (Myung Cho) Contracting Approach (Mark) Risk Areas (Mark) Plans for Future Work (Mark) AOB Executive Session (closed session for committee members) Feedback from Committee (All Hands) ------------------------------------------------------------------------------------ Dinner Explain I�ll get back to the 5 parts in a moment We have a couple of short breaks scheduled throughout the day, plus a lunch at noonExplain I�ll get back to the 5 parts in a moment We have a couple of short breaks scheduled throughout the day, plus a lunch at noon

3. Presentation Overview Top-Level Functional Requirements Specification Document Summary Interface Control Documents Safety Requirements QA/QC Requirements

4. Top-Level TMA RequirementsOptic & Instrument Mounting Requirement: Provide stiff, precision mounting interfaces for the optic assemblies and instruments: M1-M6 mirror assemblies, heat stop, Lyot stop assembly, and calibration optics M7-M9 mirror assemblies, coud� instruments M3n-M5n Nasmyth optics and instrument These �big picture� type requirements are pretty much standard for any large telescope. Our approach to quantifying the requirement, and then specifying them in the SD was: 1) approach them from a top-down look (e.g., in the error budget) (Rob has already talked about this previously) (top down come from experience, other telescope projects, and the like) and then 2) using top-down as a target, analyze our structure and (iteratively) arrive at an appropriate spec.These �big picture� type requirements are pretty much standard for any large telescope. Our approach to quantifying the requirement, and then specifying them in the SD was: 1) approach them from a top-down look (e.g., in the error budget) (Rob has already talked about this previously) (top down come from experience, other telescope projects, and the like) and then 2) using top-down as a target, analyze our structure and (iteratively) arrive at an appropriate spec.

5. Top-Level TMA RequirementsOptic & Instrument Mounting: M1-M6

6. Top-Level TMA RequirementsOptic & Instrument Mounting: M7-M9

7. Top-Level TMA RequirementsOptic & Instrument Mounting: M3n-M5n

8. Top-Level TMA RequirementsPoint, Track, & Slew Requirement: Provide accurate and repeatable pointing, tracking and slewing of the optics over their full required ranges of travel Top-down requirement from open-loop pointing (SRD) Bottom-up estimates from other large telescope as-built performance

9. Top-Level TMA RequirementsLight Path Requirement: Provide an unobstructed optical path from the sun, to/through all optics, to the instrument stations at the Nasmyth and coud� foci�with acceptable seeing and stray-light characteristics Top-down requirement (mount seeing) is NA in error budget Unobstructed, fully shaded structure with low thermal mass and ventilation. (Bottom-up via thermal analysis of mount structure)

10. Top-Level TMA RequirementsInstrument & Optic R&R Requirement: Provide for periodic instrument and optics R&R (e.g., M1 recoating operations) Top down requirement from SRD: telescope must be optimized for �efficiency� Bottom-up requirements from NIC subassembly designs

11. Top-Level Functional Requirements (cont.) Requirement: TMA shall be safe for personnel and equipment Top down: ATST Project Tenet Bottom-up: OSHA & HIOSH compliance Provide integrated safety systems for personnel and telescope (e.g., M1 cover; GIS interface, etc.) Safety reviews Etc�

12. TMA Specifications Document (SPEC-0011) The �SD� contains all the specifications & requirements that the Contractor must use when designing and constructing the TMA Performance, Engineering & Functional Specifications Traceability of specs fall into three major categories: Traceable to SDR (e.g., Jitter, Coincidence of Az. Axes) Traceable to Use Cases (e.g., Settling Times) Traceable to �BEP� (e.g., Braking, Torque Margins, Factors of Safety) Contractor required to create a Compliance Matrix that includes all numbered specs in SD States how spec will be verified (e.g., test, inspection, analysis, etc.) ? SD organized into 10 Major Subsystems + General (design, fab, metrology, shipping, assembly) + Safety requirements �CEP� Common Engineering Practices (Engineering Experience)�CEP� Common Engineering Practices (Engineering Experience)

13. 1.1 Mount Structure Requirements Performance: Mount payload definitions Overall structure characteristics Size, mass, resonant frequency Flexure (M1-M6, M3n-M5n displacements) Static & Dynamic Individual Mirror Displacements & Rotations Line of Sight (LOS) requirements (including M7-M9) Thermal Deflections Seismic Assembly & Bearing precision E.g., perpendicularity of azimuth and altitude axes. Functional & Engineering: Bearing systems Personnel access

14. 1.2 Mount Drive Requirements Performance: Alt, Az ranges of travel and limits Velocity and acceleration Pointing and tracking Jitter, stability, drift, settling time Engineering & Functional: Encoders Over-speed sensing Brakes Drives (torques, etc.)

15. 1.3 Coud� Rotator Structure Requirements Performance: Rotator payload definitions Overall structure characteristics Size, mass, resonant frequency Flexure (M7-M9, instrument displacements) Static (dynamic covered above in Mount) Individual Mirror Displacements & Rotations Thermal Deflections Seismic Assembly & Bearing Precision E.g., azimuth axis coincident with mount structure Functional & Engineering: Bearing systems Personnel access Electronic enclosure requirements

16. 1.4 Coud� Rotator Drive Requirements Performance: Azimuth range of travel & limits Velocity and acceleration Pointing and tracking Jitter, stability, drift, settling time Engineering & Functional: Encoders Over-speed sensing Brakes Drives (torques, etc.)

17. 1.5 Nasmyth Rotator Structure Requirements Performance: Nasmyth Instrument payload definitions Overall structure characteristics Resonant frequency Flexure (instrument displacements) Static (dynamic covered above in Mount) Thermal Deflections Seismic Assembly & Bearing Precision E.g., rotation axis coincident with mount altitude axis

18. 1.6 Nasmyth Drive Requirements Performance: Range of travel & limits Velocity and acceleration Pointing and tracking Jitter, stability, drift, settling time Engineering & Functional: Encoders Over-speed sensing Brakes Drives (torques, etc.)

19. 1.7 Ancillary Mech. Equipment Requirements Locking Pin Assemblies Positions Design Loads & Factor of Safety

20. 1.7 Ancillary Mech. Equipment (cont.) Enclosure Avoidance System (Safety) Cable Wraps Stiction Capacity

21. 1.7 Ancillary Mech. Equipment (cont.) ?Mirror Cover Assembly Fail-safe closure Mirror protection

22. 1.7 Ancillary Mech. Equipment (cont.)

23. 1.8 MCS Requirements Functional: TMA Control operational startup and initialization target acquisition on-target operations (offset, scan) stow and shutdown IT&C acceptance & performance tests engineering single axis motion full control of each component

24. 1.8 MCS Requirements (cont.) Functional: TMA status reporting and logging component status configuration states health and alarms faults, traces performance

25. 1.8 MCS Requirements (cont.) Functional: Interfacing ATST Common Services connection and event services property service log and archive services Telescope Control System commands modes (park, slew, track, �) trajectories status Enclosure Control System follow ECS

26. 1.9 LIC Requirements Functional: Safety detect mount-enclosure collision end-of-travel, over-speed temperature, pressure Castell keys, e-stops, doors interlock directly to hardware power report to and from GIS one-way to MCS one-way to engineering display

27. 1.10 Telescope Pier Requirements Performance: Stiffness & Capacity Soil Interface Engineering & Functional: Flooring & Stairs Man-Lift Coud� Crane Lighting

28. Interface Control Documents ICDs define the interfaces between the TMA and other �NIC� subsystems (e.g., M1) Each ICD contains 6+1 major subcategories: Mechanical (e.g., bolt patterns) Optical (e.g., beam clearance) Electronic/Electrical (e.g., cabling, power) Mass/Balance Thermal (e.g., coolant) Software/Control (Safety Issues) Explain: ICDs are notoriously difficult to write, complete, release. Don�t know why (human nature, proscrastination) Completion scheme is as follows: Whenever a subsystem undergoes an SDR, all ICDs must be initiated When the second, interconnecting subsystem undergoes its SDR all interfaces must be identified Shortly after the second subsystems SDR, the ICD must be completed and released Explain: ICDs are notoriously difficult to write, complete, release. Don�t know why (human nature, proscrastination) Completion scheme is as follows: Whenever a subsystem undergoes an SDR, all ICDs must be initiated When the second, interconnecting subsystem undergoes its SDR all interfaces must be identified Shortly after the second subsystems SDR, the ICD must be completed and released

29. Interface Control Documents (cont.) Currently there are 14 identified ICDs that �touch� the TMA 1.1/1.2 TMA-to-M1 Assembly 1.1/1.4 TMA-to-M2 Assembly (includes HS, Lyot Stop) 1.1/1.5 TMA-to-Feed Optics 1.1/1.7 TMA-to-System Alignment 1.1/2.1 TMA-to-Coud� Wavefront 1.1/2.2 TMA-to-Nasmyth Wavefront 1.1/3.1.1 TMA-to-Polarimetry 1.1/3.1.2 TMA-to-Nasmyth Station 1.1/4.4 TMA-to-TCS 1.1/4.5 TMA-to-GIS 1.1/5.0 TMA-to-Enclosure 1.1/6.2 TMA-to-SO Building 1.1/6.6 TMA-to-System Interconnects May add 1.1/6.5 TMA-to-Handling Equipment (articulated man lift attached to stationary TMA telescope-level flooring)

30. Safety Requirements This will be a �safety-first� project, from the kick-off meeting, through all phases of the Work, to the final punch-list close-out effort at the Site, and then on into operations We require the Contractor to appoint a safety officer who has no other role in the project We require the Contractor to develop and implement a project and site specific Safety and Health Management Plan Based on Safety & Health Specification (SPEC-0031) Covers work both at Contractor�s facility and at Site Safety was covered on day 1 of the review�Safety was covered on day 1 of the review�

31. Quality Assurance Requirements Quality Assurance & Management plan is requirement of Contract Requirements for this plan are spelled out in ATST Quality Management for TMA document A QA/QC officer is required by Contract