A block change options approach for the Constellation program

This paper discusses the development of a block change options approach for the Constellation program. Through the lifecycle of the Constellation program, mission objectives will change from the initial ISS focus to a lunar focus and beyond. The block change strategy described here aims to facilitate an evolutionary approach to block changes based on proactive ¿what-iffing¿ by planning for potential solutions to problems before they became real and finding high impact upgrades to utilize at the right time. An overview of the Block Change Options Tool, which was developed to aid the Constellation Program Systems Engineer is also provided. Sample analyses were performed using the tool populated with notional data for certain upgrades. These notional examples demonstrate how the tool can be used to aid in planning for future upgrades which can improve performance, fix problems or provide options for the program budget profile.