9/11/2008
Learning Objectives
The Design Process
Goal is to select the best overall (or least worst!) design for a human space mission and provide traceable rationale for the decisions
Begins with Concept Exploration and Requirement Definition
Establishes ROM cost / mass
The Mission Concept is the core of the Architectural Plan
1.
First step – broad goals that the system must meet, overall purpose of the mission
‘Qualitative’ for the most part at this point
Primary, secondary and non-technical objectives
Hidden agendas (political, social or cultural)
2. Mission Requirements
and Constraints
Transforms the broad mission objectives into quantifiable design parameters in terms of specific requirements and constraints
3. Alternate Concepts
and Architectures
Mission Concept + Element Options
Start with subject, orbit, C3 and Ground System
Used as framework for other elements
Payload unique issues may also drive process
Identify the
Identify the main parameters for each Element
Construct and ‘Prune’ a Trade Tree
Keep looking for other alternatives
Top down (goal driven) or bottom up (technology enabled)
Characterize the subsystems
Basic purpose is to quantitatively compare alternatives in terms of cost / benefit analysis
4. Critical System
Drivers
Design parameters that significantly influence cost, mass, performance, risk and/or schedule
Examine factors and look for hidden drivers
5. Baseline
Converge on optimal solution for comparison with continuing trades
6. Systems
Requirements
Attributes of a Good Requirement
7. Document and
Rationalize
8. Integrate and
Iterate…