Conceptual Design Review Design Requirements The Systems Perspective

Conceptual Design Review Design Requirements The Systems Perspective Rob Hubbard Systems Engineering

The Flow-Down Process ATST Science Requirements Design Requirements

The Flow-Down Process ATST Science Requirements Functional and Performance Requirements Strawman Concepts Design Requirements

Getting to a Concept – Input Obvious Constraints Experience with Similar Telescopes Engineering Analysis Work Shops Strawman Concepts Funded Studies Trade Studies Baseline Telescope Concept

Getting to a Concept – Ideas

Testing the Concept Performance Evaluation Error Budgets Science Requirements Design and Development of Systems and Subsystems Strawman Concept Sub-System Specs, Design Requirements No OK? (Co. DR) Cost Evaluation Yes PDR Phase Conceptual Design Review: • What passes this test? • What work remains?

Some Hard Constraints from the SRD • Resolution, photon flux and sensitivity require a four-meter class telescope. • Resolution requirement also leads to a high-order adaptive optics system. • Wavelength coverage from 0. 3 to 28 m leads to an allreflecting telescope.

Some Challenging Requirements • Resolution Requirement (Image Quality) – Even with a 4 -meter aperture, a world-class site, high-order AO system, this remains challenging. • Stray Light Requirement (Coronal Observations) • Polarization Requirement (Polarimetry)

Design Requirements Documents • M 1 Mirror Assembly – SPEC-0007 (Ron Price) • M 2 Mirror Assembly – SPEC-0008 (Ron Price) • Enclosure – SPEC-0010 (Mark Warner) • Telescope Mount Assembly – SPEC-0011 (Mark Warner)

The Systems Approach The diverse and sometimes competing requirements placed on ATST forces a rigorous and aggressive systems approach during all phases of the project.

ATST Systems Orientation

Responsibilities of Systems Engineering • • • Design Requirements Flow Down Document and Drawing Control Interface Control Error Budgets Standards End-to-End Modeling Quality Assurance Plan Acceptance Test Plans Integration Plan

Responsibilities of Systems Engineering – Co. DR Emphasis ü • • Design Requirements Flow Down Document and Drawing Control Interface Control Error Budgets Standards End-to-End Modeling Quality Assurance Plan Acceptance Test Plans Integration Plan

Systems Overview • Telescope Systems and Subsystems Definition • Interface Control and the N 2 Diagram • Documentation Control • Error Budgets – Top Down • Error Budgets – Bottom Up

Glossary and Acronym List

Document and Drawing Control

Interface Control and the N 2 Diagram

N 2 Diagram Detail

Top Level Systems • • 1. 0 2. 0 3. 0 4. 0 Telescope Assembly Adaptive Optics Instrument Systems High-Level Controls and Software • 5. 0 Enclosure • 6. 0 Support Facility and Buildings

Telescope Assembly Subsystems • • • 1. 1 1. 2 1. 3 1. 4 1. 5 1. 6 Telescope Mount Assembly M 1 Assembly M 2 Assembly Feed Optics Thermal Systems Scattered Light Control Probably specific to D&D Phase. Likely to be reabsorbed later.