Documents / Official release
This Defense Intelligence Reference Document, dated 23 March 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office. It is one of the advanced technology reports produced under the Advanced Aerospace Weapon System Applications Program. The paper is a historical survey of claimed links between superconductors and gravity, covering Podkletnov's gravity shielding claims, the Li and Torr theories, and NASA and Tajmar experiments. It concludes that no replication exists and that research in this area is fraught with experimental difficulty.
From the source: Release of 2026-09-18 Incident: 3/23/10, 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 is a historical survey of efforts to determine whether superconductors might play a role in producing, detecting, or modifying gravity-related effects in a laboratory setting. It reviews the main theoretical and experimental lines of work in that area and attempts to connect superconducting materials with gravitational-wave or propulsion-related concepts. Because the topic is highly contested within the scientific literature, the report spends substantial attention on experiments of disputed value and on controversial theories, especially claims that rotating or energized superconductors might generate anomalous gravitational effects. Overall, the document treats the subject as an exploratory research area with potentially major implications if any real effect were verified, while also making clear that the evidentiary base remained weak, that prominent claims had not been convincingly replicated, and that both the underlying theory and the experimental record remained deeply disputed.
UNCLASSIFIED//POll Offl@IAL YSlii &P•tlf permanent magnets), and a larger disk was spun at lower temperatures, the shielding effect would be extremely small. The experiment has remained controversial since its publication. Very few scientists put any stock into it at all. Most damning to Podkletnov's case was the complete lack of any supporting evidence that the experiment had ever actually taken place. As the Podkletnov article began to slowly circulate, Li and Torr published another article (Reference 18) expanding on their earlier investigations in an attempt to outline the physical mechanism underlying the production of a gravitomagnetic field inside a superconductor. Basic to their consideration was an assumption of near-zero magnetic permeability in the superconductor and the requirement of coherent alignment of lattice ion spins in conjunction with a time-varying applied magnetic vector potential field. With this understanding, they determined values for laboratory-scale induced internal gravitomagnetic fields and external gravitoelectric fields and how these fields could be maximized. However, in 1994 Kowitt (Reference 26) claimed that their 1992 and 1993 results were not credible owing to their assumption of near-zero permeability inside a superconductor. However, Li and Torr rather effectively countered shortly thereafter, and Woods (Reference 3) also called that criticism into question. Later, however, Harris (Reference 27) argued in a more effective critique that Li and Torr's previous results were erroneous because they assumed arbitrary (and extremely small) distances from the lattice ion to the observer, thus producing unreasonably large effects. In fact, Harris pointed out that the correct estimation of the induced gravitoelectric field outside a superconductor is some 20 orders of magnitude smaller! No evident rebuttal has been forthcoming from Li or Torr. At about this time, Torr and Li parted company, although both continued to work in the area. In 1995, Li was sufficiently convinced that she now had the answer to producing an artificial gravity field that could be measured outside a superconductor that she approached R. Kaczor at NASA to fund further development of her version of the theory. By this time the Podkletnov paper had been "discovered," and a few forward thinking NASA scientists determined that perhaps it was time to initiate some research in the area. After all, now there was a peer-reviewed theoretical basis for a peer reviewed experiment. Also at this time, this author and colleagues began preliminary experiments in Toronto after contacting Podkletnov. Our approach was to attempt to reproduce the 1992 Physica C spinning disk experiment with additional data from Podkletnov but using a better cryogenic design with the possibility of mechanically spinning the disk. This author and colleagues started manufacturing our own large YBCO disks in house. The following year, while still at the Tampere University of Technology's Institute for Materials Science, Podkletnov and Vuorinen attempted to publish updated spinning disk experiments in the British Journal of Physics D Applied Phys Vol. 29 (1996), but the paper was withdrawn in a cloud of controversy. It was later published on the Internet (Reference 28) under the authorship of Podkletnov and Levit and then Podkletnov alone. Vuorinen and Levit had coauthored papers on ceramic processing with Podkletnov previously. This new experiment involved a large AC levitated 27 -cm diameter bi-layer sintered YBCO disk spun to 5,000 rpm using two-phase high frequency radiofrequency (RF) "rotation" fields and allegedly showed gravitational shielding in the few percent range. The cryostat design was somewhat better in that there was considerably more shielding of the test mass from buoyancy and thermal UNCLASSIFIED/ /FOA OFFitl.t.k W&lii &P•kY 6
Not linked to a story yet.
Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 16 pages are in the text index: search them above, or from the library's search.