3437. Development and Implementation of a Space Systems Mass Properties Process

Paper

Abstract

ATK Launch Systems is the world leader in solid rocket motor design and manufacturing. The Systems Engineering and Integration (SE&I) team within the Advanced Programs group was tasked with developing a mass properties process for very large and complex systems. This process was to include a definition of what mass properties information needed to be tracked, how the information was going to be calculated and tracked, and where the information would be stored. The SE&I team chose to use the AIAA S-120-2006 [1] standard as a basis for the new process. This standard provided suggestions for what information should be tracked, and what the mass growth allowance (MGA) and mass margin (MM) depletion schedule should look like for a space system, including mass assessment Technical Performance Measure (TPM) guidelines. With the AIAA guidelines [1] in mind, the SE&I team developed a new mass properties control plan. This control plan included the process for calculating MGA and MM depletion schedules, and mass assessment roll ups, including TPMs, for assemblies with components in various design stages. The traditional roll up as outlined in the AIAA standard [1] suggests components within assemblies follow the same schedule with different percentages based on maturity. ATK chose to develop an approach to allow different schedules for each component / assembly based on the component / assembly specific development schedule and maturity. The mass properties process also included the method for tracking detail part changes real time, and calculating and reporting TPMs for mass assessment, the number of component mass changes, and the time sequenced mass properties. All of the knowledge contained within the control plan was then captured within a MATLAB application which calculated the time sequenced mass properties, the mass depletion schedule of the system, and output the required TPMs programmatically. The MATLAB application also created a formatted mass properties report, and a data file containing all of the time sequenced mass properties information for use by other groups. This process and application can be used on any large system, and it is ideal for systems which implement the AIAA approach [1] to mass properties control. With little time and effort on the part of the mass properties engineer, a great deal of data can be created programmatically.