Space Systems

Space Systems Working Group

FireSAT: Model vs Documents Alone

Provide an example of Model Based Systems Engineering applied to a Space System

FireSat Example (From Space Mission Analysis and Design (SMAD), Third Edition, by Wiley J. Larson and James R. Wertz (editors).) 

  • Realistic and sharable
  • A mission to detect identify and monitor forest fires from orbit
  • Widely regarded as definitive text on space systems for concept/feasibility studies
  • Examples are sufficiently detailed  to create models

FireSAT Text as System Design Documents and Descriptions 

  • FireSAT text resembles documented system design (requirements, functions, interfaces, analysis and trades)
  • Presentation of information is organized similar to how silos form
  • Works fine for a text book
  • Naturally illuminates the areas integrated modeling is intended to address 

Types of Document-based Information in FireSAT 

System Documents

FireSAT Example

Concept of Operations

Mission Objective, system requirements

Requirements (SRDs, FRDs etc)

system requirements

Interfaces (ICDs etc)

Data flow diagram, system requirements

Functional Designs

Power functional decomposition


Mission Objective

Analysis-specific engineering reports (trades, reliability etc)

Solar Array selection

End-to-end Information systems spec

Data flow diagram