Positron Aerospace Propulsion

This Defense Intelligence Reference Document, dated March 2, 2010, provides a technical assessment of positron-based aerospace propulsion. Produced under the Advanced Aerospace Weapon System Applications (AAWSA) program, the document explores the potential of antimatter—specifically positrons—as a high-energy-density fuel source. The report highlights that positron annihilation provides a specific energy significantly higher than chemical, fission, or fusion sources, while avoiding the radioactive byproducts associated with nuclear fission or antiproton annihilation. The document details various applications, including air-breathing turbojet/ramjet engines for unmanned aerial vehicles (UAVs), ramjet-assisted missiles, and single-stage reusable vehicles (SSRVs) for low Earth orbit access. It also examines the feasibility of positron-powered rockets for manned interplanetary missions to Mars, comparing solid-core, gas-core, and Sänger photon rocket concepts. A significant portion of the report is dedicated to the challenges of positron production and storage. It discusses current methods of production at particle accelerators and proposes future solutions, such as undulator-based sources at the International Linear Collider. Storage challenges, including the Brillouin density limit and the use of porous media like silica aerogel to stabilize positronium (Ps) atoms, are analyzed in depth. The report concludes that while positron propulsion is currently in a conceptual phase, advancements in storage and production could enable revolutionary aerospace capabilities within the next decade, such as global-range UAVs and faster transit times for human exploration of the solar system.