Conceptual Design Review

Design Requirements

The Systems PerspectiveRob Hubbard

Systems Engineering

The Flow-Down Process

ATST Science Requirements

Design Requirements

The Flow-Down Process

ATST Science Requirements

Design Requirements

StrawmanConcepts

Functional and Performance Requirements

Getting to a Concept – Input

Baseline Telescope Concept

Strawman Concepts

Experience with Similar Telescopes

Funded Studies

Trade StudiesEngineering Analysis

Obvious Constraints Work Shops

Getting to a Concept – Ideas

Testing the Concept

Science Requirements

Science Requirements Strawman

Concept

Strawman Concept

Error BudgetsError Budgets

Sub-System Specs, Design Requirements

Sub-System Specs, Design Requirements

Design and Development of

Systems and Subsystems

Design and Development of

Systems and Subsystems

Performance Evaluation

Performance Evaluation

Cost Evaluation

Cost Evaluation

PDR PhasePDR Phase

OK?

(CoDR)

Yes

Conceptual Design Review:

• What passes this test?

• What work remains?

No

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 all-reflecting 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

• M1 Mirror Assembly– SPEC-0007 (Ron Price)

• M2 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

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

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 – CoDR Emphasis

Systems Overview

• Telescope Systems and Subsystems Definition

• Interface Control and the N2 Diagram

• Documentation Control

• Error Budgets – Top Down

• Error Budgets – Bottom Up

Glossary and Acronym List

Document and Drawing Control

Interface Control and the N2 Diagram

N2 Diagram Detail

Top Level Systems

• 1.0 Telescope Assembly

• 2.0 Adaptive Optics• 3.0 Instrument

Systems• 4.0 High-Level

Controls and Software

• 5.0 Enclosure• 6.0 Support Facility

and Buildings

Telescope Assembly Subsystems

• 1.1 Telescope Mount Assembly

• 1.2 M1 Assembly• 1.3 M2 Assembly• 1.4 Feed Optics• 1.5 Thermal Systems• 1.6 Scattered Light Control

Probably specific to D&D Phase. Likely to be reabsorbed later.