Engineering challenges to the long term operation of the International Space Station

The U.S. Congress has maintained an intense interest in the ISS program sin ce its inception. In the Appropriations Act of 1997, the Senate of the Unit ed States included language directing National Aeronautics and Space Admini stration (NASA) to have the National Research Council (NRC) under take a st udy that evaluates the engineering challenges posed by extravehicular activ ity (EVA) requirements, United States and non-United States space launch re quirements, the potential need to upgrade or replace equipment and componen ts after Assembly Complete, and the requirement to decommission and disasse mble the facility. NASA and the NRC decided the focus should be on the anticipated challenges in the continuous operation and maintenance of the ISS after assembly of th e on-orbit facility has been completed. This would encompass the operationa l years, from late 2004 (if the current schedule holds) to 2020 - 2025. This executive summary overviews the results of this NRC study. It focuses on the U.S. operation of the ISS after Assembly Complete, including coopera tive efforts by the United States and Russia. The paper summarizes the prim ary findings and recommendations in each of the areas considered during thi s two-year NRC study. (C) 2001 Published by Elsevier Science Ltd.