AbstractNASA's future space communication needs and requirements will be addressed through a space communications network that mirrors the terrestrial Internet in its capabilities and flexibility. NASA's needs and requirements for future data gathering and distribution by this Space Internet have been obtained from NASA's Earth Science Enterprise (ESE), the Human Exploration and Development in Space (HEDS), and the Space Science Enterprise (SSE).To address NASA's future needs, we propose and describe an integrated communications infrastructure based on Internet technologies, the architectures within the infrastructure, and the elements that make up the architectures.The architectures meet the requirements of the enterprises beyond 2010 with Internet compatible technologies and functionality. The elements of an architecture include the backbone, access, inter‐spacecraft, and proximity communication parts. From the architectures, technologies have been identified which have the most impact and are critical for the implementation of the architectures. Published in 2002 by John Wiley & Sons, Ltd.