DOW-UAP-D126, AAWSAP DIRD, Advanced Nuclear Propulsion for Manned Deep Space Missions, March 2010

This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD examines advanced nuclear propulsion for crewed deep-space travel and argues that human missions beyond the Moon would require propulsion systems with both very high thrust and very high specific impulse, which the author contends are difficult to achieve with conventional chemical, nuclear-thermal, and nuclear-electric systems. The report focuses on concepts derived from Project Orion, the discontinued General Atomics nuclear pulse propulsion study sponsored first by ARPA and later by the U.S. Air Force between 1958 and 1965, in which a spacecraft would be driven by repeated nuclear explosions. In this case, the DIRD emphasizes small non-fission-triggered fusion explosions using deuterium, magnetic mirrors, and other unconventional ignition concepts intended to avoid the inefficiencies associated with small fission devices. It presents these ideas as a possible pathway to crewed missions across the solar system, while also linking them to broader visions of long-range human expansion into space. The document is exploratory in character and depends on several unproven ignition methods, enabling technologies, and engineering assumptions. Overall, it is a theoretical examination of fusion-based pulse propulsion concepts rather than as a documentary account of a technology nearing practical realization.