Evaluating Flight Software Effort Estimation and Reusability Approaches for Planetary Exploration

Spacecraft Flight software is a critical component of every planetary mission. Besides the efficiency and cost-effectiveness of its development, proper planning efforts to maintain budgetary control, and adherence to the timeliness of schedule for cost-constrained missions are crucial for mission success. This is because there are initially many unknown factors such as technical uncertainties, resource availability, and mission requirements, making it extremely challenging to plan, estimate costs, and quantify the associated risks of developing novel capabilities and features. One solution for keeping costs reasonable and managing scope to mitigate these challenges lies in the adoption of software reuse and inheritance strategies. Software reuse and inheritance play a significant role in cost estimation as they offer reduced development cost, shorter development schedule, improved reliability, increased efficiency, and standardized consistency, ultimately contributing to more accurate estimations and enhanced management of the complex development process. As planetary missions become more frequent, and competitive, it is not feasible for each mission to develop architectures and infrastructure capability anew. However, successful reuse can be elusive and challenging given the distinct nature of each mission. The purpose of this study is to investigate the effectiveness of the approach taken by software management teams at NASA Jet Propulsion Laboratory (JPL) in modeling the cost of software upfront prioritizing the use of inherited flight software product lines that enable high reusability and ensuring reliability through proven flight records. We will examine historical trends of software reuse practices at JPL to highlight ways to maximize inheritance benefits across multiple planetary missions. Lastly, we will perform a quantitative analysis to assess the feasibility of a reusable software base, identify limiting factors by using the Europa Clipper flight software and its FSW Core Product Line (FCPL) as a baseline, and conclude the results. By quantifying the benefits of software reuse in cost savings, our findings will contribute to a comprehensive understanding of the efficiency and effectiveness of flight software reuse and inheritance for cost estimation. Moreover, the results of the analysis will inform and influence cost exercises, leading to risk-informed cost-effective decision-making for flight software effort estimation and inheritance considerations in future JPL missions.