Space Vehicle Flight Software Analysis via Monte Carlo Driven Simulation
Mark C. Smith · 2009
Quite often, space vehicle development programs experience significant schedule delays and cost overruns, in part, due to issues associated with flight software development and integration. Trends indicate that hardware has become more sophisticated and user requirements more demanding while flight software development practices have not kept pace. Historically, flight software design has focused on completing multiple small on-board tasks within static time constraints. The increase in hardware capabilities and user demands has breached this form, thereby creating significant new demands on flight software. While many factors contribute, a primary step toward resolving these problems is to develop tools that allow for a more complete understanding of proposed flight software behavior much earlier in the development lifecycle. By applying a simple Monte Carlo algorithm to spacecraft timing requirements, it is possible to create a dynamic model that parallels flight software behavior in mission environments. Constructing this model before software development begins is facilitated by hardware design. Hardware communication is a critical responsibility of flight software and its requirements are typically established before software development is approached. When a basic Monte Carlo algorithm is used as a representation of time and applied to these requirements, the result is a model that mimics the behavior of a particular flight software implementation. Understanding the behavior of flight software as it is constrained by defined boundaries gives developers the ability to foresee and resolve issues that could otherwise surface in a later stage of development. The advantages of avoiding these obstacles in an earlier stage of development include lower project cost, less time debugging, better resource allocation and improved schedule compliance.