Technology and architecture : informing investment decisions for the future of human space exploration

Abstract

NASA's detailed programmatic goals, system architectures, and mission designs for future human spaceflight beyond Earth orbit remain unspecified. Given this uncertainty, it is not clear exactly which technologies are necessary for enabling future exploration. The process of establishing technology development strategy relies on methods to evaluate the benefits and cost of potential investments. While the cost of technology development is often the primary uncertainty, in this application it is particularly difficult to quantify the benefit of technology development without a clear understanding of the system architecture to which it is being applied. With destinations and exploration strategy left to be determined, the potential benefits of any given technology can not be stated with certainty. While challenging, it is necessary to identify a prioritization of these development projects for early investment before the system architecture is defined. This thesis develops a framework for evaluating technologies in the context of long term system architecture planning for the future human space exploration transportation system. An abstracted solution-neutral formulation of the transportation architecture to any arbitrary destination is defined as a combination of multiple architectural sub-problems. To evaluate technologies within the tradespace, two measures are adapted from design of experiments literature. Main effects analysis is used as a measure of a technology's influence on the best architectures. Similarly, the strength of coupling effects between two technologies is captured by interaction effects. The measures of technology influence and coupling enable architects to prioritize technologies based on their performance, and to organize investment decisions by those that must be treated together and those that can be taken in parallel. The system architecture tradespace for Mars, the Moon, and two representative Near-Earth Asteroid (NEA) missions are explored and presented. Results from the proposed influence and coupling measures are used to evaluate technologies considered in the tradespace and to understand the benefits and tradeoffs presented by investing in different technologies in relation to each destination. Following the results from each tradespace, some suggestions of favorable pre-cursor missions to the Moon or NEAs are proposed as preparation for a future Mars exploration mission.