Slide 1

Camera OverviewNadine KuritaProject Manager

LSST DOE CD-1 ReviewNovember 1 - 3, 2011LSST CD-1 Review SLAC, Menlo Park, CA November 1 - 3, 2011 LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#1OutlineCamera Project OverviewCamera Design OverviewDesign Reviews & Project RisksCost & Schedule Summary

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#2A Broad-based Collaboration of Institutions Has Been Assembled to Deliver the CameraSLAC National Accelerator Laboratory: Overall project management, camera body and mechanisms, cryostat subsystems, data acquisition and camera controls, integration and testBrookhaven National Laboratory:Science sensors, electronics and raft assembliesLawrence Livermore National Laboratory:Optics, corner raft assemblies, wavefront sensingFermi National Laboratory:DAQ Analysis toolsInstitut National de Physique Nucleaire and de Physique des Particules (IN2P3-Collection of multiple labs):Front-end electronics, sensor testing, filters, filter carousel, camera calibration, slow controlsUniversity-based instrumentation groups:Harvard, U. of Pennsylvania, Purdue, Ohio State, U. of Illinois, UC Santa Cruz, U. of Arizona, U. of Tennessee, UC Davis LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#4Contributors Camera Team SLACA. RoodmanO. SaxtonR. SchindlerJ. SingalS. Tether G. Thayer M. TurriBNLJ. FrankJ. FriedJ. HauptI. KotovP. OConnorS. PlateV. RadekaJ. StewartP. TakacsPurdueE. AlagozK. ArndtA. Biccum B. Erny I. Shipsey B. Xin K. Ziegler

SLACD. ArnettT. Azemoon G. BowdenC. BrackettD. BurkeR. Claus S. DigelM. FossK. GilmoreG. GuiffreP. HascallJ. HodgsonM. HufferW. InnesT. Johnson S. KahnJ. KuN. KuritaJ. LangtonH. LeungD. MarshS. MarshallM. NordbyF. ONeilE. OrtizJ. Panetta A. RasmussenK. Reil

IN2P3B. AmadeP. AntilogousE. AubourgA. BarrauY. CargagnoJ. ColleyG. DaubardC. DeLaTailleC. EvrardR. FlaminioJ. Giraud L. GuglielmiC. JuramyP. Karst D. LabatH. LebboloD. MartinM. MiglioreN. MorgadoY. Orain E. PerbetF. RiviereS. RussoD. TerrontV. TocutC. VescoviF. VezzuD. VincentF. Virieux

LLNLB. BaumanD. CarterS. OlivierV. RiotFNALE. GottschalkC. Green J. KowalkowskiHarvard UniversityS. AmatoN. FeltP. DohertyJ. GearyJ. OliverU PennN. Dressnandt G. Mayers M. NewcomberM. Reilly O. Rifki R. Van BergU of ArizonaE. CheuK. JohnsD. TompkinsOhio StateK. Honscheid UC Santa CruzT. Schalk

U Tenn/ORNLB. BlalockC. BrittonN. EricsonP. StankusUniversity of IllinoisJ. HartJ. ThalerInst. Physics Czech P Kubanek M. Prouza UC DavisT. TysonUC BerkleyG. Jernigan

Color Key Institution Manager Contributor #5Key Staff Identified and Management Structure is Well UnderstoodKey managers have been appointed in these areas:Project Office, System Engineering, Project Administration, Performance & Safety Assurance ManagersRecent addition to lead Quality Assurance

Large sub-systems are led by:Sub-System Manager (physicist)Engineering Manager/Sub-system Architect

6Product Oriented WBS is Well Defined and Used to Organize All Aspects of the Sub-systems DeliveryLCA-125, WBS Dictionary

WBSTitleKey Deliverables3.1ManagementProject Office, PMCS, performance safety & assurance3.2Systems Integration Requirements, risk, design integration, system analysis3.3Science Raft SystemSensors, science raft mechanics and electronics3.4Corner Raft SystemSensors, corner raft mechanics and electronics3.5OpticsL1-L2, L3, filters3.6Camera Body & MechanismsCamera body, shutter, exchange system, camera cooling3.7CryostatCryostat housing, grid, utility trunk, refrigeration system3.8Control System, DAQ and System ElectronicsControl system & DAQ software/hardware, power supplies, protection system3.9Integration & TestIntegration and testing of the above deliverables LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#7Responsibility Assignment Matrix Defines the Accountability of WBS DeliverablesMore detailed RACI (Responsibility, Accountability, Consulted, Informed) is being developedRevision 1Responsibility Assignment MatrixN. KuritaSLACM. NordbySLACJ. LangtonSLACJ. KuSLACM. HufferSLACJ. StewartBNLR. Van BergUpennV. RiotLLNLJ. ThalerU. IllinoisA = AccountableWBS Name3.01ManagementA3.02Systems Integration A3.03Science Raft SystemA3.04Corner Raft SystemA3.05OpticsA3.06Camera Body & MechanismsA3.07CryostatA3.08Control System, DAQ and System ElectronicsA3.08.01Camera Control Core (CCC)A3.08.02DAQA3.08.03Camera System ElectronicsA3.09Integration and TestA LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#8Camera Design Overview LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#9Key Technical Challenges that Drive the Camera Design3.2 Gigapixel camera, large focal plane (63.4-cm diameter) with small (10 micron) pixels189 sensors, 4 side buttable with 250 micron interchip gapsDeep, fully depleted CCDs with novel AR coating allow for broad spectral coverageFast readout (3.2 Gigapixels in 2 seconds) led to sensors with 16 segmentsLow noise coupled with the large number of signal linesAnalog and digitizing electronics in the cryostatIncreased capacity needed for focal plane cooling systemTight constraints on envelope, mass, and dissipation of heat to ambientTight alignment and flatness tolerances (13.5 micron p-to-v) on the sensor arrayLarge curved filters with broad spectral coverage and tight uniformityAs this is the only instrument for the observatory, it needs to provide 10 years of continuous operation (reliability and maintainability)

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#10

Designs Meet the Tight Constraints and All Subsystem Interfaces to Camera are Defined

Cross section through telescope and cameraM1M3 primary mirrorCameraM2 MirrorKey interfaces:Weight,Size,Heat,Utilities,Handling,Controls.

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#11

Camera LayoutSystem parsed into constituent elementsUnderstand their functionality and how they fit and work togetherCamera ParametersPropertyValueLifetime15 yearsIncident half-angle in air14.2o-23.6oFocal plane diameter634 mmMaximum mass3000 kgMaximum diameter1650 mmTotal length3732 mmFilterL1 LensUtility Trunkhouses support electronics and utilitiesCryostatcontains focal plane & its electronicsFocal planeL2 LensL3 LensCamera Section

1.65 m(5-5) #12

Layout of Camera OpticsCamera Optical ParametersPropertyValueL1 clear aperture diam1550 mmL1-S1 spherical radius2824 mmL1 center thickness82.23 mmL2 clear aperture diam1102 mmFilter clear aperture diam750 mmFilter thickness range14.2-26.2 mmL3 clear aperture diam722 mmL3 center thickness60 mmFilterL1 LensUtility TrunkCryostatDetector planeL2 LensL3 LensShutterCamera Optical Elements #13Fully-Integrated Camera

Camera Housingsupports the entire cameraL1-L2 Assemblypre-assembled structure holds both lensesUtility Trunkouter panels removedBack Flangemechanical interface to telescopeFilter Loader access portfor swapping out a filter during daytime accessFlexible Skirthermetically seals Camera housingCamera Parameters3.2 Gigapixels0.2 arcsec pixels9.6 square degree field-of-view2 second read-outf/1.2 beam = short depth-of-focusBroad spectral coverage: 3501040nmFully Assembled Camera #14Skirt Removed: Standard Maintenance Configuration

Region for access to mechanisms and lensesL1-L2 support strutsL1 support ring space frameLight baffle ringsAuto Changer frameCamera Opened for Access #15L1-L2 Assembly Removed: Exposing Auto Changer

Exchange System Primary FunctionsSupports a filter in the field of view (a.k.a.: on-line) during observationsStores filters in the clean environment of the CameraMoves filter into the field of view by remote command during observationsAccommodates removal/replacement of filter(s) from/to the CameraAuto Changer filter railShutter railAuto Changer drive linear actuatorFilterManual Changer access port aligns with Auto Changer railsAuto Changer structure mounts to Camera BodyL1-L2 Assembly Removed LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#16Auto Changer Removed: Showing Shutter

Shutter ParametersPropertyValueActivation time1 secClear opening aperture734 mmMin clearance to L3 lens10.8 mmGuide rail supports blade tips2 sets of 3 stacked bladesDrive rail housed in dust coverAuto Changer RemovedShutter Animation

#17Shutter Removed: Exposing L3 Lens and Front of Cryostat

Segmented detector plane CCDs visible through L3 Lens1Camera Body Integrating StructureProvides primary support for L1, L2 lenses, filters and exchange systemMaintains clean, hermetically sealed environment for all opticsPresents primary structural interface to telescope at back flangePresents primary thermal interface to telescope at outer housingOuter housing and front stiffening flangeGusseted back flangeCryostat outer housingShutter Removed #18Camera Housing Removed: Showing Filters in Carousel

Carousel structurerotates to position selected filter in position to bring on-lineOff-line Filtersstored in annular region surrounding CryostatFilter clamp mechanismholds filters in CarouselExchange System ParametersPropertyValueFilter clear aperture diam756 mmMax exchange time90 secMax filter mass35.5 kgOn-board filters5L3 lens mounted to front of CryostatCarousel and Cryostat Exposed #19Carousel Removed: Showing Cryostat and Utility Trunk

Cryostat housingL3 lensUtility Trunk structureCryostat support cylindercantilevers off back flangeBulkhead panel for all camera servicesCryostat Cantilevered off Back FlangeBack flange mounts to telescope rotator #20

Cryostat Section: Showing Raft TowersGridsupports Rafts(-125 oC)Cryo Platesupports and cools Front End Crates (-130 oC)Cold Platesupports and cools Raft Control Crates(-40 oC)Pump plate and vacuum system components(~5 oC)L3 flange (~5 oC)L3 lens (~-5 oC)Raft Sensor Assembly9 CCDs on support plate with ball/groove mount to Grid(-100 oC)Front End Cratefront end electronics in copper structure (-120 oC)Raft Control Cratedigitizing electronics in copper structure(-35 oC)Cryostat housingvacuum envelope, support structure(~5 oC)2Cryostat Integrating StructureProvides stable support for CCD detectors on focal planeProvides stable thermal control of cold CCDs and front end electronicsRemoves all process and radiant heatMaintains CCDs in clean high-vacuum environment to prevent contaminationCryostat SectionCryo Shroudshields Grid from radiant heat (-130 oC) #21Science and Corner Raft Towers

Guide sensorsCorner Raft Tower4 towers, one in each cornerSpring-loaded hold-down clampsupports Raft off GridRaft Control Cratemounts to Cold PlateScience Raft Tower21 towersSplit wavefront sensorCorner Raft Control Cratemounts to Cold PlateFront End Cratetriangular shape fits in Grid corner bays #22Wavefront Sensor LayoutGuide Sensors (8 locations)Wavefront Sensors (4 locations)Curvature Sensor Side View ConfigurationFocal plane2d40 mmSci CCDThe LSST Focal Plane 63.4 cm in diameter

Entrance Window on Back SideGuard RingSixteen 1-Mpix segments 10mm pixelsBonding Pads100mm thick,5kW-cm Si42mm3.5 degree Field of View (634 mm diameter) LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#23

Reverse-Angle Camera View: Utility Trunk Contents3Utility Trunk Integrating StructureHouses all on-telescope support utilities and services for the CameraProvides a single location for disconnect of all lines to the CameraCools all support utilities using chilled air from telescope top-end plenumAllows for access to electronics crates during camera servicingMaintains clean, sealed environment for all utilitiesDIN rail for protection system controllers Control crates for support electronicstiming module, power control, optical transition module, ethernet switchHeat Exchanger Canister for refrigeration systemUtility Trunk cooling blower/filter unitScroll pumps for vacuum systemsUtility Trunk structure (not shown) is cantilevered off the back of the Cryostat support tubeUtility Trunk Contents #24

Camera Off-Telescope ComponentsElevation View of Dome and Summit FacilityRefrigeration system ground unitCompressor chassisServicing and mixing equipmentCamera Control SystemComputer rackCamera Data Acquisition System DAQ computerData storageUtility RoomComputer and Control Rooms LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#25Design Reviews & Project Risks LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#26Design reviews are required by the Project Office and well documentedLCA-98: Documents process and procedureProject Office Required ReviewsSystem Function Review/Requirement ReviewDevelopment ReviewConceptual Design Review (CoDR)Preliminary Design Review (PDR)Final Design Review (FDR)Manufacturing Readiness Review (MRR)Pre-ship or Integration Readiness Review (PSR/IRR)Safety Reviews

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#27Successfully held System Requirement Review and Sub-System Conceptual Design ReviewsOct 2010 Preliminary System Function ReviewNov 2010 Filter Exchange System Review CompleteFeb 2011 Science Rafts & Electronics, CCS & DAQ CompleteMay 2011 Camera System Requirements, Camera System Design, Camera I&T, Shutter and Cryostat Aug 2011 OpticsTwo Request for Immediate Action (RFA1) before moving to the next phaseFilter Exchange System Requirements (closed)3rd Sensor vendor (working)Discussions with HEP to obtain additional funds to engage a third vendor have indicated that they will make a decision pending the outcome of the current prototype results.e2V has produced 2 working sensors and initial tests are promising. ITL will have produced sensors in early November and will provide testing results in December.Sub-System Development Reviews CompleteInternal reviews held in FY10On-going reviews by sub-systems to address their development plans and how they burn down their risks.June 2011 SLAC CD-1 Directors Review

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#28Laboratory and Agency ReviewsAug 2011 NSF PDRCamera team composition and organization is excellent and the project is being managed very wellAlthough the Camera project is composed of one hundred and eleven persons (~30 FTEs) spread over four DOE laboratories, nine universities and one foreign organization, the team is cohesive and well--organized. The panel believes the good teamwork and high level of staff motivation is the result of the following. A clearly defined management structure, with well--defined roles and responsibilities.Strong and supportive project management.Open and frequent communication within the Camera project team and with the LSST project staff.October 2011 SLAC CD-1 Directors ReviewSuccessfully held and found Ready for CD-1

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#29Project risk management process used to manage camera development, LCA-29Camera risks documented in registry, LCA-30Actively planning development work to burn down risks and monitor progress131 total risks identifiedManaging 74 active risks40 are closed5 top risks have detailed mitigation plans and key milestones to monitor progressScience CCD performance (17.3/25)Refrigeration Performance (14.7/25)Guide CCD performance (13.3/25)CCD Yield (13.3/25)Filter coating performance (13/25)Others resolved through the normal development /engineering design processCamera risks are well understood and development plans and funding is supporting their mitigationsDevelopment plans are documented & submitted by sub-systems. Development reviews were executed during the R&D phase by all sub-systems. LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#30CCD Performance Risk Mitigation Plan(Risk ID CA1)Fiscal YearsRisk ExposureHighModerateMinorInsignificantCriticalIF the CCDs do not simultaneously meet k3bey requirements (flatness, read noise, crosstalk, diffusion PSF), THEN the camera will not meet the throughput and image quality allocations. Technology study Understand and model device characteristics Study contract 3 vendors Receive working sensorsTechnology choice Establish test lab at BNL

Current AssessmentFirst Article Fabrication, Yield Runs & Raft Integration Full Fabrication & Acceptance Process FinalizationPrototype Raft Tower with system electronicsDemonstrate yield and quality controlFull automation of QA test within LSST institutionsAssembly/test rate trials Full-Spec Sensor Prototype Multivendor competitionFabricate sensor meeting all LSST specificationse2v funded to develop full-spec science sensor & mechanical packageMech samples receivedFirst operable test samples received Sep 2010Redesigned operable samples Nov 2011Operable samples with final AR coat Feb. 2012ITL/STA delivered mech package and test deviceFirst fully tested operable samples Dec 201120072010201120122013201420152016201720182019Start Camera I&TPreShip ReviewCD-1 ReviewCD-3a ReviewCD-2 ReviewCamera Verification Manufacturability/Yield Runs & Raft Integration Prototype Raft Demonstrate yield and quality controlDevelop integration and QA test capability within LSST collaborating institutionsCD-3b- Review LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#31Sensors news: 2 vendors just recently fabricated prototypes

e2v CCD250 (operable)STA3800 (mechanical sample)

(setup device, Oct. 28)

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#Performance on key specs based on the results of Phase 1 and Phase 2 programs with e2v and ITLKey performance specCCD250 (e2v)STA3800 (ITL)QE (red bands) QE (blue bands)Redesigned AR coat in development Read noise @ 550kpix/sNot tested yetPSFFlatnessProcess mod. In progressFill factorPhase 2 results are hot off the press and not final.For details see Paul OConnors breakout talk at 2PM LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#Cost & Schedule Summary LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#34 Level 2 Milestones Key MilestonesLevel I Baseline MilestonesScheduleCD-0, Approve Mission Need6/20/2011CD-1, Approve Alternative Selection and Cost RangeQ2FY2012CD-3a, Approve Start of Long Lead ProcurementsQ4FY2013CD-2, Approve Performance BaselineQ2FY2014CD-3b, Approve Start of ConstructionQ4FY2015CD-4, Approve Project CompletionQ4FY2020Level II Baseline MilestonesScheduleConceptual design complete (Ready for CD-1)Q4FY2011Prototype Science Sensors ReceivedQ2FY2012Phase 1, Vertical Slice Test Complete - *before CD3a*Q4FY2012Sensor final design complete *before CD3a*Q3FY2013Camera long lead designs complete (Ready for CD-3b) First Article Sensor Contract, options for additional production sensorsQ3FY2013Camera preliminary design reviews complete & Performance Baseline established (Ready for CD-2)Q1FY2014Phase 2, Vertical Slice Test Complete - *before CD3b*Q1FY2014First article filter ready for coatingQ1FY2015Cryostat Cryo-plate PO placedQ3FY2015Camera design complete (Ready for CD-3b)Q1FY2016Shutter Blade PO placedQ2FY2016Cryostat Assembly Ready for IntegrationQ2FY2017Filter exchange system fabrication complete (Accepted delivery)Q3FY2017Cryostat and sensor raft integration completeQ4FY2018Optical lens assembly, L1/L2 and L3 completeQ4FY2018Camera fully integratedQ2FY2019Camera Pre-Ship ReviewQ3FY2019Sensor Production CompleteQ3FY2020Camera verification complete, KPPs achieved (Ready for CD-4)Q4FY2020L2 milestones total of 19 > 2/year.1056 Milestones in the schedule or roughly 117 milestones per yearMilestone dictionary has been drafted35LSST Camera Summary Schedule

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#36Detailed technical logic with only funding constraintsSub-system milestones linked to management milestones4735 activities including 1056 milestonesMost of the resources were imported from the Basis of Estimate Worksheets into P6

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#37Cost Estimates Are MatureEstimates are mature for this stage of the projectCost Books/Basis of Estimate contains, WBS Description3D models, drawingsDetailed cost estimatePart number, drawing number, vendor, notes, weight, qty, cost, etc.Supporting quotations, drawings, catalogs, etc.Contingency/Risk AssessmentCross referenced to P6 activity IDsHigh price materials are based on vendor quotations recent updated quotesSensors, CeSiC Grid, CeSiC Raft, Carbon Fiber Shutter Blades, Refrigeration System>43% material estimates are from catalogs or vendor quotationsMost labor estimates came from detailed engineering experienced based on similar programs40 % (45M) Contingency

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#38Camera Level 2 Cost & Effort Summary Current data from P6 & CobraNOTE: The cost data shown here is current, however, the sub-system talks reflect data results from June during our Directors Review. Residual Risk ContingencyAdditional management reserves to execute the projectMonte Carlo Simulation used to evaluate if project has sufficient reserves to successfully execute the projectLSST Camera Total Project CostEscalated Total Cost ($K)Cont. Total Cost ($K) 3.01 Management $ 9,467 12% $ 10,603 3.02 Systems Integration $ 6,489 40% $ 9,085 3.03 Science Raft System $ 36,844 42% $ 52,318 3.04 Corner Raft System $ 5,209 30% $ 6,772 3.05 Optics $ 21,304 31% $ 27,908 3.06 Camera Body & Mechanisms $ 3,732 30% $ 4,852 3.07 Cryostat $ 9,990 35% $ 13,487 3.08 Control System, Data Acquisition System and System Electronics $ 8,911 30% $ 11,584 3.09 Integration and Test $ 10,720 30% $ 13,936 Residual Risk Contingency $ 6,755 Total Project Cost ($K) $112,666 40% $157,300

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#39Preliminary Funding ProfileFiscal Year FY11FY12FY13FY14FY15FY16FY17Total ($M)OPC $1.9 $5.5 $3.0$10.4 TEC - Design$6.0 $9.0 $9.0 $9.0 $39.0 TEC - Fabrication$1.0 $7.4 $38.5 $42.0 $25.0 $107.9 Total Project Cost ($M)$1.9 $5.5 $10.0 $ 16.4 $47.5 $51.0 $25.0 $157.3 Funding is for the MIE portion of the DOE LSST Program and covers the design, engineering, assembly and verification testing of the camera at SLAC.DOE operations money is planned for FY18 and FY19 to cover camera shipment, preparing the camera summit facility, summit camera verification, and support to the effort for camera observatory integration and test. LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#404700 Activities have been leveled with funding constraints and are consistent with DOE funding

FY2012FY2013FY2014FY2015FY2016FY2017FY2018FY2019FY2020Incremental Funding7.410.016.447.551.025.00.00.00.0 LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#41Commitment/Funding Profile Consistent with NSF Lowest Cost to the Government ScheduleNSF has not provided a notional funding profileNSF directed the project to produce a Lowest Cost to the Government ScheduleThis is defined as a front loaded schedule to achieve the lowest cost, but with a realistic labor/procurement ramp-upThe Camera project produced an accelerated schedule to meet the camera need date presented by the overall project at the NSF PDR. This schedule was the nearest solution to stay within the DOE funding guidance, however we willNeed ~$47M of funding moved into the early years (FY2012 FY2015) Deliver the camera with a partially filled focal plane that is sufficient for the First Light phase of the projectShip the balance of the focal plane science rafts to the summit before the completion of Observatory Science Verification LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#42Commitment/Funding Profile Consistent with NSF Lowest Cost to the Government Schedule

LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#43CD-1 Key DeliverablesAll key deliverables have been completedAQ & PPEP has been reviewed by DOE site office, OPA and HEP Program Office and ready for final signaturesCD-0 Approve Mission NeedAcquisition Strategy (AQ)Preliminary Project Execution Plan (PPEP)Appointment of the Federal Project Director (FPD)Approve Integrated Project Team (IPT)Develop a Risk Management PlanComplete a Conceptual DesignConduct a Conceptual Design ReviewComplete a Conceptual Design ReportPrepare a Preliminary Hazard Analysis ReportDevelop and Implement an Integrated Safety Management PlanEstablish Preliminary Quality Assurance Program (QAP)Identify general Safeguards and Security requirements for the recommended alternativeComplete National Environmental Policy Act (NEPA)Strategy by issuing a determination (i.e., EIS, EA)Conduct Independent Project Review or External Independent ReviewUpdate PDS, or other funding documents for MIE and OE projects, and OMB 300s, if applicable. #44CD-1 ReadinessProgrammaticWBS Dictionary - scope of project definedRisk Registry risks defined and managedCost Estimate detailed Basis of Estimates developedSchedule resource loaded approaching CD-2 maturityLong lead procurements definedManagement plans draftedTechnicalRequirements & interfaces definedSystem Function Review/Requirements ReviewLSE-59, Camera Requirements DocumentLCA-48, Camera SpecificationExternal Interfaces ReleasedInternal Interfaces DraftedTechnical design maturity exceeds CD-1 requirement (Conceptual Design) & provides sufficient information to develop a solid cost estimate rangeCamera Conceptual Design ReviewsAll CD-1 criteria have been metCamera designs are beyond or at conceptual design and technically meet the requirementsBaseline documents (functional, design, cost & schedule)

#45SummaryStrong and experienced technical staffThe key personnel and management staff has been identifiedScope is well defined and organized. Deliverables by the DOE are clearly segregated, and interfaces are mature for this stage of the projectDesigns are mature and have been successfully reviewed by external panelsProject risks are well defined and are actively being mitigatedDetailed cost estimates created a robust cost rangeResource loaded schedule has been developed and leveledSchedule is logically linked to support leveling per funding agency guidanceStart EVMS early to help manage the collaborationMajor Upcoming Milestones & EventsReceive operable sensors test results from 2 vendors in October and NovemberVertical Slice Test Phase 1 Spring FY12Demonstration of kinematic mounting concept in FY12Demonstration of increased capacity of the refrigeration system in FY12 LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#Page46End of Presentation LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#47The LSST Optical System - Modified Paul-Baker Design

Primary and Tertiary MirrorsSecondary MirrorCamera Lenses LSST CD-1 Review SLAC, Menlo Park, CA November 1 3, 2011#48Document #Date EffectiveStatus

LCA-102-A29 September 2010ApprovedAuthor(s)

J Langton

DESIGN REVIEW REPORTNadine Kurita

Subsystem/Office

Camera Body & Mechanisms

The Design Review Report Guidelines:

Purpose/Goal of the Review to be completed by the review moderator prior to the start of the review. Lists special boundary conditions for the review. Introduction and Outcome Summary of the Review to be completed by the review committee. Overall impression and general conclusions. Final recommendation to proceed to the next phase of the project.

Request for Action (RFA) will be completed by the review committee, and tracked by the System Engineering team: Tier 1 Immediate RFA: these items require immediate formal action and closure in writing prior to receiving approval to move into the next phase of the project. Tier 2 - RFA: these items require formal action and closure in writing prior the next review. Tier 3 - Concerns: these are comments or soft recommendations that require action by the design/engineering team, but a response is not required to approve the review. Observations these are general comments and require no response.

Title of the ReviewFilter Exchange System Conceptual Design Review

Type of Review: Conceptual Design Review

WBS: Camera Body & Mechanisms, Filter Exchange System

Form LCA-99 RevA, Design Review ReportRefer to LSST Design Review plan document, LCA-98 on docushare, for full guidelines on executing design reviews.

Page 2 of 11

Page 11 of 11

Presented By:M. Nordby, J. Ku, G. DaubardReview Date: September 29, 2010

Reviewers, Department & Institution :J. Langton, Accelerator Directorate, SLAC (Chairperson)Jean-Charles Castagna, Accelerator Directorate, SLACPierre Carst, Marseille, IN2P3Gary Muller, NOAOFrank ONeil, PPA Safety, SLAC

Review Moderator: Nadine Kurita, LSST Project Manager

Distribution:LSST-camera@lsstcorp.org

Review Materials & Supporting Documents:Collection-1991Agenda: Document-9691Review Slides: LCA-103: 1-FilterExchCoDR-IntroOverviewLCA-104: 2-FilterExchCoDR--AutoChangerLCA-105: 3-FilterExchCoDR-CarouselLCA-106: 4-FilterExchCoDR-ManualChangerLCA-107: 5-FilterExchCoDR-SystemsIntSupport Documentation: Collection-2006Attendance Sheet

Purpose/Goal of the Review:1. Approve the driving requirements and functionality of the Filter Exchange System. Approve that conceptual design approach meets the requirements and functionality. Approval of development plans.2. Confirm that the key deliverables as outlined in LCA-100 (Design Review Content Summary) has been presented.

Special Considerations:1. Due to schedule constraints, this review is occurring before our Observatory System Specification (OSS) Review and the Camera System Requirements Review (SRR). Confirm that the baseline requirements and functionality terms are known and the impacts of the TBDs are understood. Key driving requirements are defined.2. The project is preparing for a CD-1 and is starting on a second round of basis of estimates. It is accepted that only a brief status on the cost and schedule will be presented.

Introduction and Outcome Summary of the Review:The reviewers concur that, accepting the items noted under request for immediate action below, and given the special considerations above, the goals of this review, as defined in LCA-100-A, have be met.The performance, functionality and performance requirements for the hardware are established and understood by the presenters and approved by the reviewers.The specification and conceptual design of the subsystems it very impressive and approved by the reviewers.Development and test plans are extremely thorough, well advanced and approved by the reviewers.Given this was a conceptual level review the design team has completed a significant and impressive amount of system requirements and specifications, engineering analysis, systems integration work, test and development work and planning.Technical risk assessment and mitigations plans are well constructed and highly advanced for a concept level review.Request for Immediate Action:The requirements for filter location accuracy, repeatability and stability are not completely defined. The effect of these requirements on image quality and system calibration are not fully understood. These issues should be resolved prior to advancing further into preliminary design of the auto-changer.

Request for Action:Complete requirements for hardware protection and fault tolerance need to be finalized and validated for current hardware design.The appropriate applicable technical safety standard needs to be agreed. Particulate and out-gassing specifications need to be finalized as soon as practicable to allow to proper inclusion in test articles test plans.Confirmation of the acceptability of the light baffle design should be obtained as soon as practicable. The limited space available to modifications of the light baffle could negatively impact preliminary design work.Concerns:LSST is an extremely large project spread between many organizations, locations and technical disciplines. This is the first formal CDR for the SLAC LSST camera subsystem. Are LSST project wide managers and stakeholders fully engaged in the significance of this milestone? How does the LSST project wide management ensure that all stakeholders are cognizant of the progress of this milestone, fully engaged, and understand the importance of timely comment? Are LSST project wide review milestone notification requirements and communication protocol in place to ensure all interested parties / stakeholders have been given opportunity to comment?

The auto-changer, carousel and manual changer each use a different design for capturing the filter. A common design should be considered.

There are numerous custom mechanical components specified in the conceptual design (motors, gearboxes, brakes, etc). Use of commercial off the shelf components should be considered wherever practicable.

The presented design for locating the filter, and providing accurate capture and release, is to have precision features machined into the filter structure and adjustable elements on the auto-changer for transport and in the auto-changer frame for in place alignment. Given finalized location, repeatability and stability specifications, and a full tolerance study, it may prove that adjustability on each individual filter element may be required, or more effective. It is not clear how alignment of the carousel capture release mechanisms is accomplished.

The filter in place location system is over constrained. The presenters explained that the over-constrained system had a lower probability of distorting the filter then other constraint configurations. It wasnt 100% clear that the analysis supporting that determination included all possible tolerance stack up and misalignment issues. (note: carousel requirement C-EXCH-069 states that the filter must not be over constrained while being held by the carousel.)

The auto-changer trucks and pivot arm are fitted to the guide rails by machine tolerances with precision clearances to allow the motion of the followers along the guide. This net clearance could lead to unpredictable dynamic motions, IE: chatter, of the filter as the autoexchanger operates. This condition could also prove difficult to reliably produce under test conditions. Some form of preloading of the truck / pivot arm followers should be considered to minimize the possibility of chatter.

During exchange the filter pitch is defined by the swing arm pivot guide. The length of the pivot arm is short compared to the overall dimensions of the filter. Small clearances at the pivot arm guide could result in large motion excursions of the filter pitch and reduced clearances to adjacent components. Possible lengthening of the pivot arm could be explored.

Should a mechanical block feature be added to the flip rails to ensure the trucks cannot run off the fixed rails should the flip rails not be in the correct configuration, and control system faults occur, during filter exchange.

The mass spec for the filter (C-EXCH-009) is not 100% consistent with values given on slide 13 of the carousel presentation.

The magnetic coupling for the carousel capture release mechanism may prove difficult to implement and / or unreliable. Since the filters are only exchanged at one location on the carousel is it not possible to activate the mechanism(s) via a more direct mechanical means ? (e.g. pushing a release latch similar to the auto-changer mechanism). Or could eletro-mechanical actuators be energized via a slip ring behind the main ring gear (?).

Observations:I would be useful if in the future there was a slide that specifically listed the required elements-topics defined for the review and explicitly states that they are complete or not, and if not complete why the review is proceeding, eg: restate items from LCA-100-A and checklist them off complete-incomplete with explanation. If would also be helpful if the checklist also pointed to the slide(s) that support the item complete assessment.A significant and impressive amount of engineering and design work has been completed supporting the chosen carousel / auto-changer concept. Many questions, comments and alternatives have been exchanged by the reviewers regarding the details of that work. A significant amount of work has also been completed by the presenters in Value Engineering / trade studies for the system. A more prominent position for the value engineering, in the presentation, and possibly a clearer presentation of the trade evaluations (like a decision tree of other graphical representation) may have helped answer a number of the reviewers comments and alternative suggestions.Forces and stresses results would be clearer to some if presented in English units, in addition to the metric.It is assumed that analysis and testing of the entire back flange, camera housing, auto-changer and carousel structure will be completed in time to address any issues that may arise in the operation of the complete camera structure. Though beyond the scope of the review, no analysis of the autochanger loads into the camera housing and possible effects on the L1-L2 support system were presented and no analysis of the carousel loads into the back flange, and possible effects on the camera housing- L1-L2 support system were presented. It is assumed that any loads deflections caused by the auto changer and carousel into the L1-L2 support and back flange are within acceptable limits.The auto-changer structure, locating one end of the flip rail, mounts to the camera body. The other end of the flip rail mounts to the back flange via the fixed portion of carousel structure. The load deflection path between the ends of the flip rails is long and complicated. Operation of the flip rails could be effected by relative deflections between the two ends of the flip rail.It is assumed that the flip rail carousel interface is controlled per normal ICD protocol.Preliminary analysis of the lifetime for some components is less than required. Further analysis and design optimization is required to close out this issue.Since space in the overall system is at a premium, and there is a large motor, actuator, sensor count, is there enough room set aside for the cabling required to support the motion control systems. Should there be an ICD created to control this space usage? REVIEWER COMMENTSONeil comments:The only issue I have is the need to identify appropriate technical safety standards for the project.Castagna Comments:General observations:The team gave an impressive presentation that was more than one would expect in a conceptual design review.A lot of work was put into determining the best compromises to attain the requirements.The overall impression is one of a solid design that has been thought thru but that will require some optimization because of the numerous interfaces and potential failures of single components.

Request for immediate action:Nothing in the design seems to be a show stopper that would prevent going ahead with the solutions proposed

Request for action:A plan of action should be proposed in the case of a catastrophic jamming of the auto changer. How do we recover from a filter being stuck in mid position?

Concerns:-I would agree with Gary that transferring the adjustable interface points to the filters rather than on the fixed parts would be a big plus in the precise positioning of the filters.

-If the above suggestion is too hard to implement, it might useful to verify the stack up of tolerances on the different main assemblies: Filter frame, auto changer, carrousel, manual changer. This would provide for a better understanding of how much flexibility is needed to accommodate for the variations from one filter to the next.

-The third wheel of the trolley that is supposed to set the angular position of the filter during transfer is very close to the pivot point. The ratio between the distance of this wheel to the pivot and the diameter of the filters could induce larger angular variation then expected on the filter during transfer. It could also cause the handling of the filter to be not as stiff as we wished for (vibrations during the transfer).

-The interfaces between the filters and the numerous kinematic mounts, whether on the auto changer or the carousel, should be optimized with hardened materials to avoid wear of the contact surfaces. This is especially true for spherical contacts on a flat surface where stress is a lot higher.

Observations:The construction of the prototype should help greatly in making the whole system comfortably reliable.

Karst comments:1) The optical specification are not known. It should be the base of the design. It could be interesting to precise what hypothesis has been taken for the design (positionning, optical beam, distribution of tolerance)2) The space is a main constrain, the volume dedicated to the sensors and cables could complete the conceptual design3) The latch for the clamping of the filter on the truck is composed of two parts, one on the filter frame and the other one on the autochanger. The Filter frame is not a part of the Exchange system. That could be a problem for the updated design of the system because of the share of responsability.4) Considering there are six filter frame, it could be useful to have adjustable components on them for the positionning. That will allow to release the tolerances on the fabrication.

Muller Comments:The following report is in response to the material presented at the LSST Camera Filter Exchange System Conceptual Design Review that was held on September 29, 2010 at the KIPAC 2nd Floor Conference Room at SLAC. Gary Muller participated in the review as a panel member via telephone and gotomeeting.com.The presentations and other supporting material were made available to the panel on-line on September 28, which gave the panel limited time to study the material prior to the review. I had no prior knowledge of the filter exchange system design that was presented. With this in mind, the following are my responses to the information presented in the review. Overall ReviewThe overall impression I got from the review was that the material presented looks very good and the basic design looks sound. The carousel design looks straight forward with no challenges that cannot be solved with good design & engineering. The manual filter changer concept looks like a good way to handle the filters in safe and controlled environment and the auto changer is very impressive and is in my opinion, the most challenging mechanism to design given the space constraints and interface requirements with the other components.The graphical images and animations presented were extremely useful in conveying the design intent, function, and structural analysis of the exchange system but some components were difficult to see and the lack of access to the solid model files prevented a more thorough study of the mechanical design.The systems engineering approach that was presented is also impressive. The requirements flow down, interface control document structure, and trade studies indicate that the project is serious about project management and documentation.Below are my comments and concerns about the various mechanisms.Captivating the filter holdersThe three major filter exchange components (auto changer, carousel, and manual changer) each had a completely different design and completely different interfaces to achieve the same task; captivate and hold the filter housing. This raises the question: Why cant the same design used for captivating the filter holder on all three components?By standardizing on one design, a lot of complexity could be eliminated. For example, the manual changer captivating mechanism looks like it could be identical to the carousel captivating mechanism and could use the same interface that the carousel captivating mechanism uses.One approach to consider would be to develop the design of the captivating device for the auto changer first since it appears to be the most challenging design given the space constraints, plus it will be actuated the most frequently and must be the most reliable. Then adopt that design for the carousel and manual exchange mechanisms. The design would necessarily be compact.The design used on the carousel appears to be the most developed of the three designs and has undergone several design and testing phases. It is reminiscent of an air hose quick disconnect. Some of the advantages include a rotary motion (60 deg rotation?) to lock/release the shaft into the receptacle, sensors integrated into the package, and the use of brake cable for actuating it in remote locations (however, a pull open/pull closed cable arrangement similar to a motorcycle throttle cable may be preferable). The disadvantage is that it has a lot of parts that tend to make it bulky. Without having the benefit knowing the history of the development of this device, I didnt understand the benefit of using this particular design. Was it chosen for reliability concerns or possibly load carrying capacity? Did you consider a design that functions essentially like a Dzus fastener (which is basically a shaft with protrusions on the end that engage into a slotted hole and locks in by a quarter turn of the shaft)? See: http://www.southco.com/product/configurators/82.aspx?coid=38&cid=7438.Such a design would allow the shaft to rotate to provide the locking/releasing rather than the receptacle as is the current design. This approach would enable the receptacle (slotted hole in this case) to be incorporated into the filter holder and the shaft/actuator would be mounted to the carousel. Since there would be no shafts mounted on the filter holder that protrude out, the interface locations could be moved (by clocking them around the perimeter of the filter holder) closer together to allow this type of captivating device to be used on the manual exchanger as well as the carousel. Additionally, an identical captivating device (2 per side) could be located on the opposite side for the auto changer that would be outside of the field of view and would not interfere with the wheel trucks. If this approach could be implemented, it would have the following benefits: One design for captivating the filters on all three mechanisms. Less mechanism testing and less parts. There would be no moving parts (latches, etc.) on the filter holders. Could eliminate mechanism on manual changer that unlatches filter from auto changer when handing off filter to manual changer.A design that might be considered is a simple shaft with a tapered end and dowel pin like protrusion that fits into a slotted hole and rotates a quarter turn to captivate the filter. See the figure below. The shaft could be actuated by a spring loaded rotary solenoid, stepper, or gear motor that is limited to a quarter turn rotation to keep the shaft in an orientation that captivates the filter when powered down. The shaft/actuator assembly would be mounted on the carousel, the auto changer truck assemblies, and the manual changer. The filter housing would have no moving parts (such as spring loaded latches) on it. H-e sensor vanes could be mounted on the filter housing and the sensors mounted to the mechanisms for sensing proximity. Additional h-e sensors would sense the rotational position of the shaft to determine the lock/release state. When a handoff occurs four shafts are engaged and rotated into the locked position until it is safe to make the handoff.

Kinematic Hard pointsIt was difficult to see the kinematic hard points that position the filter frame in the on-line position but it was mentioned that adjustable (in x, y, & z) kinematic balls would be mounted to the to the red structural frame and the filter holders would have mating features on them that were not adjustable. If it is the case that filter repeatability is the driving requirement rather than optical alignment then I would suggest eliminating any adjustments of the kinematic mount.

The four point mount over constrains the filter holder. Can you eliminate one of the balls in the red frame, move the other ball to the middle, make the mating surface cone, and adjust the design of the other two (that get clamped) so that it is still fully constrained?

Auto Changer

Linear rails with Ball screwsUsing linear rails with ball screws looks like a good idea. They are low friction and are less likely to generate debris than an ACME screw. However, ball screws can back drive so you should add a non-back driving (worm) gear box on the end of each rail. I think Mike had indicated this was the plan. I like the idea of driving both rails with a single motor. By doing this, the rail tables will remain aligned with each other (along the y-axis) and not cause the mechanism to bind. Using flex couplings between the drive shafts will prevent binding due to shaft misalignment and pinning them together will prevent slipping which could cause the rail tables misalign (along the y-axis). We use step pins (which are essentially set screws with a dowel pin like shaft on the end) to locks couplings and gears to shafts. Cross member between rails (yoke)Is it possible to eliminate the yoke that is attached to the rail tables? It appears to over constrain the rail tables. Also, consider eliminating the pivoting drive train linkage that attaches to the yoke and replace it with a two pivoting links (one for each side) that attach to the rail tables on one end and the trucks on the other end for a more direct link between the rail tables and trucks. Is it necessary to mount the baffle to the yoke? Can it be mounted to the red support structure instead? If the yoke can be eliminated, this may be possible. Eliminating the yoke will also reduce the weight of the exchange system.

If space constraints will not allow the yoke to be removed, then you might consider incorporating flexures that can accommodate out of parallelism conditions between the two rails and slight misalignments (in the y-axis) of the rail tables.

Wheel trucks & v-groove railsThe rail design with v-grooves and trucks looks like the best solution for transporting the filter from the carousel to the on-line position and back. This approach clearly allows the filter to make its way around the cryostat housing without colliding with the outer camera body or the lenses in front of the filter mechanism. The main concern I have with the design presented, however, is the section of rail (flip rail) that pivots out of the way to make clearance with the carousel. This opens up the possibility of the trucks running off the rails if for some unforeseen reason, the control system, or a sensor fails. I did not see any failsafe mechanical interlock to prevent such event from occurring so the control system will have to perform correctly.

You may want to consider adding a boss onto the pivoting section of rail that blocks the path when the rails are pivoted out of the way for rotating carousel.

Another solution that would eliminate the risk of the trucks ever running off the rails would be to modify the path of the rails so that the rails do not penetrate the swept volume of the carousel and limit the travel of the trucks. The handoff location would then be closer to the auto changer and the carousel would capture the filter and retract it back into its home position. This of course would require adding actuators and rails (not necessarily v-groove rails) on the carousel in each filter position. The figure below shows a possible alternate path for the rails.

It may be easier to manufacture the v groove rails and rollers if the shapes were inverted. That is to say, make the roller with the positive shaped v and the rail with the negative shaped v.

CarouselThe carousel design looked somewhat preliminary but the intent was successfully communicated. The images show the motors interfering with the conical outer ring structure but I am sure those details will be address as the design proceeds. The baseline design showed two torque motors and four brakes equally spaced around the ring gear. Other options would be to stack the brakes on top of the motors and have three motors/brakes for more margin of safety if a motor fails. Driving the carousel using torque motors to the handoff position, which is determined by an (absolute) encoder, and locked into position by brakes that are engaged when powered down looks like a feasible solution.

The magnetic couplings mounted to gear reduction to actuate the clamp mechanism looked somewhat risky in the sense that there is no direct mechanical coupling between the motor and the clamp mechanism. What happens if the torque load on the magnetic coupling exceeds its capacity (2 Nm) and the clamp cannot release or lock? It seems like a direct mechanical coupling would be a more reliable solution because it could transfer more torque. I am assuming that magnetic couplings were used to satisfy the requirement that states: The Carousel shall be capable of rotating in either direction to minimize the cycle time. I also assume that means an unlimited number of turns which would preclude the use of cables. If so, it may be an unnecessary requirement. For example, if the carousel were limited to a minimum of 1.2 turns (6 sockets) then a cable wrap could be added to deliver power & logic to the rotating carousel and thus, the filter captivating mechanisms could be actuated directly rather than through the proposed magnetic coupling & gear reduction. The torque motors could even be located on the carousel if that would free up more space. To minimize the cycle time, and in anticipation of the next filter exchange, the carousel could be rotated one turn when necessary, in parallel with other telescope operations such as reading out the detectors and slewing, if it couldnt be rotated during an observation. Then the carousel would be ready to travel the shortest distance for the next filter exchange.

Manual ChangerThe overall design of the manual changer looks good. Using two linear rails and a lead screw to drive the filter housing into the camera looks feasible. However, as described above, I think the device for captivating the filter holder in the manual changer could be identical to the carousel.

Filter Exchange Time BudgetIn the filter exchange time budget, you estimated that it would take 91.4 seconds to exchange a filter. 60 seconds were allocated just for rotating the camera to orient the x-axis horizontally and back again to the observing position. Would it be faster to point the telescope to zenith and back than to rotate the camera when changing a filter?