AAWSAP DIRD, Positron Aerospace Propulsion, March 2010

This Defense Intelligence Reference Document was prepared by the Defense Intelligence Agency's Defense Warning Office and dated 2 March 2010. It is one of a series of advanced technology reports produced under the Advanced Aerospace Weapon System Applications program. It looks at using positrons as fuel for air-breathing turbojets, ramjet-assisted missiles, single-stage reusable vehicles and rockets for a manned Mars mission, and it also covers positron production, costs and storage. It concludes that a first positron-powered flight around the globe could be possible within 10 years.

From the source:Release of 2026-09-18 Incident: 3/2/10, Las Vegas, Nevada. Released with redactions. 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 positrons as a possible fuel for advanced aerospace propulsion, arguing that antimatter offers extraordinary energy density and could, in principle, support applications ranging from long-endurance aircraft and missiles to single-stage launch vehicles, onboard power systems, and crewed Mars missions. At the same time, it makes clear that the concept depends on resolving major unsolved problems in producing positrons in sufficient quantities and storing them safely for long periods, and much of the document’s discussion of flight systems and Mars missions remains conceptual rather than closely tied to demonstrated engineering practice. Its overall conclusion is that positron propulsion is theoretically attractive, but remains highly speculative as a practical technology because its core production and storage requirements remain unsolved.

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POSITRON ENERGY CONVERSION FOR ONBOARD POWER
Research was conducted on positron utilization in a standalone, closed-loop, high-power
system. 42 A Brayton cycle eng ine (Figure 14) was investigated with output power of 100
kW, consistent with Mars Reference Mission specifications. 43 • 44 Results show efficiencies
of 25-30 percent and positron consumption of 7 μg/hour.
Such a power system would have practical meaning for fast transits to Mars where
positron consumption does not dominate rocket positron consumption.
l
Figure 14. Closed Brayton Cycle Using Positron Annihilation (courtesy Positronics Research LLC}45
In addition, a small, 110-watt, positron-driven generator (Figure 15) for small, onboard
tasks was designed around the NASA Glenn Research Center Stirling Radioisotope
Generator,46 with heat provided by Ps gamma rays.
SIJrfing Convertor 1(55 We) S1irting Convertor 2 (55 We)
- ----------~------------
Eleclric Power Oullel Mag,,ollcSloev
Figure 15. Conceptual 110-Watt Positron Closed-Cycle Generator Based on the NASA Glenn Research
Center Stirling Radioisotope Generator47 (courtesy Positronics Research LLC} 48
UNCLASSIFIED/ /FOR 8FFIEl>L 1!55 ON! X
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