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Introduction
1.5 How? (The General Design Process)
The verification and validation model is broken down into different phases of the design cycle. Created by Dr. Frankie Zhu of HSFL
A useful systems engineering model for the spacecraft lifecycle is the “V-model” or “V&V process”. The process begins on the top left with stakeholder analysis, then moves down the definition and design process: system/mission requirements definition, system architecture/subsystem performance decomposition, tradespace exploration/design solution, and component development. Along the design process, the team must pass the system requirements review (SRR), preliminary design review (PDR), and critical design review (CDR) [NASA Systems Engineering Handbook]. When verifying and validating that the design meets the requirements and the stakeholders will be happy, the verification and validation process includes component performance analysis, subsystem performance analysis, system performance analysis, and mission operations. Along the way, the team must pass the system integration review (SIR) and flight readiness review (FRR). Although this diagram looks very linear, the design process is iterative and should include various loops returning the design team to earlier stages of the design process when incompatibilities are identified. This textbook will cover the intricacies of the design process by describing spacecraft design drivers, the role and design of each subsystem, and best practices for the design process.
Detailed design is expected to meet requirements with adequate margins at an acceptable level of risk.
High confidence exists in the product baseline & adequate documentation exists (or will exist in a timely manner) to allow proceeding with fabrication, assembly, integration, and test.
~90% of the detailed design has been completed.
Does the design “close”?
In plain language, the design is essentially complete and ready to move into the fabrication/assembly phase.
Examines tests, demonstrations, analyses, and audits that determine the overall system (all projects working together) readiness for a safe and successful flight/launch and for subsequent flight operations.
