1. NGAO Instrumentation Preliminary Design Phase Planning September 2008 Sean Adkins

2. 2 Overall Approach Priorities –Support PDR success Design and build to cost objectives Systems engineering goals Interface definitions –Move instrument designs forward Address most challenging design aspects Develop firm interface definitions with AO system Support other design activities Develop full plans for design and fabrication Initial Plan –Limited in scope due to funding uncertainty –Focused on “minimum” needs to support AO system design –Pragmatic, based on heritage designs and proven concepts –Takes advantage of design overlaps between imagers –Seeks to develop synergy for probe arms between TT and d-IFS

3. 3 PD Phase Objectives for Instruments Overall –Instrumental wavefront error budget and internal wavefront error allocations for the instruments –Strategies for controlling and minimizing instrumental wavefront error –Science driven pixel scale requirements and basis for implementation –AO system to instrument alignment requirements and methodology –Calibration requirements and methodology –Firm interface definitions for optical, mechanical, electronic and software interfaces for the instruments –Virtual instrument definition for the NGAO master command sequencer

4. 4 PD Phase Objectives for Instruments Imagers –Wavelength ranges for the visible and near-IR imagers –Sensitivity error budgets for the visible and near-IR imagers –Coronagraph performance and companion sensitivity –Visible IFU conceptual design and feasibility assessment –Optical design to at least a PD level for both instruments –Conceptual design for mechanical systems and thermal systems –Software requirements –Best effort costing d-IFS –Ensquared energy and throughput budgets –Performance estimates for slicer and spectrograph –PD level probe arm design in collaboration with the near-IR TT sensor probe arm design –First cut optical design –Conceptual design for mechanical systems and thermal systems –Software requirements –Best effort costing

5. 5 Key Issues Design pre-requisites –AO system narrow field optical characteristics –Confirmation of available envelope and mounting configuration for instrument Initial AO System to instrument interface definitions –Optical (first draft in KAON 555) –Mechanical (first draft in KAON 555) –Electronic/Electrical (very straightforward, heritage based) –Software (relatively straightforward, likely heritage based) Alignment and calibration concepts for instruments on AO System Trade studies –AO and Instrumental Wavefront Error –Pixel Scale –Short Wavelength cut-off –IFU Capability (visible imager) –Ensquared energy (d-IFS) Performance and error budgets –Sensitivity –Background –Companion Sensitivity –Wavefront Error –Probe Positioning Performance (d-IFS) –Size and Mass

6. 6 Initial Project Plan

7. 7 Initial Resource Requirements 124 hours of interface related effort in v17 NGAO project plan Resources for proposed plan: