Matrix modeling methods for spaceflight campaign logistics analysis

Abstract

This paper proposes a matrix-based modeling approach for analyzing spaceflight campaign logistics. A campaign is considered to be a series of coordinated flights delivering cargo at a location or node. A matrix representation of the cargo carried by flights for consumption in different time periods (or missions) is formulated. The matrix adopts specific structures based on the nature of the campaign, thereby allowing a quick visualization of the campaign logistics properties. A logistics strategy index is proposed for quantifying manifesting strategies, and a flight criticality index is defined to help in identifying important flights from a cargo-delivery perspective and aid in assessing impact of flight cancellations, failures, and delays. The method is demonstrated on a lunar outpost establishment and is also applied in modeling the logistics of the International Space Station. A manifest (M) matrix and flight dependency (D) matrix is created for crew provisions cargo delivered to the ISS over a period of 10 years. It is found that the overall logistics strategy index for crew provisions has so far been 0.85 (meaning 85% of the crew provisions cargo is prepositioned on average for each mission) and that the prepositioning is for up to a maximum of four future missions at a time. Copyright © 2009 by Afreen Siddiqi. Published by the American Institute of Aeronautics and Astronautics, Inc.