UNCLASSIFIED // PUBLIC RELEASERELEASE 06 · SEPTEMBER 18, 2026
PENTAGON UFO FILE · DOCUMENT · DOW-UAP-D117AAWSAP DIRD, Metallic Glasses for Aerospace Applications, December 2009
This is one of the 38 technical reference papers commissioned under the Defense Intelligence Agency’s Advanced Aerospace Weapon System Applications Program, dated December 2009 and filed under Las Vegas, where the program’s contractor, Bigelow Aerospace Advanced Space Studies, was based. Its subject is pure materials science, with no sightings in it: metallic glasses, and whether they could ever earn a place in aircraft and spacecraft.
What a metallic glass is, and the paper’s verdict
Ordinary metals are crystalline, their atoms packed in regular grains. A metallic glass is an alloy made so that its atoms freeze in a disordered, glass-like arrangement instead. The paper treats that structure as double-edged: it brings very high strength and some unusual manufacturing advantages, but the material tends to fail suddenly, with little ductility and weak resistance to fatigue under repeated loading.
The author’s bet is on composites, in which a glassy matrix is combined with a second phase. These keep most of the strength while resisting cracks far better, perhaps well enough to stand in for high-strength steel where space for structure is tight. Wider use, the paper judges, would take 20–50 years of progress in alloy design and processing, and above all in lightweight systems, including aluminum-based options.
Where it fits in the series
A DIRD is a literature synthesis, not a record of new experiments, and the release cautions that this summary reflects thinking at the time of writing, not a current endorsement. The released copy carries redactions. Like several papers in the series, it reads as a survey of an emerging technology rather than anything tied to UFO reports.
The official description
From war.gov/UFO, released September 18, 2026, quoted in full
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 surveys metallic glasses as a potentially important class of aerospace materials and describes their amorphous structure as offering very high strength and unusual manufacturing advantages, but also significant drawbacks, especially poor ductility and fatigue resistance. The document concludes that the most promising aerospace applications are likely to come from metallic-glass-matrix composites rather than single-phase glasses, because these composites can retain high strength while greatly improving fracture toughness and fatigue performance, potentially enough to substitute for high-strength steels in some space-limited structural uses. At the same time, the report judges that broader aerospace use will depend on substantial progress over the next 20–50 years in alloy design, processing, and especially the development of lightweight systems, including aluminum-based options.