Plasma and magnetohydrodynamic (MHD) propulsion and power for hypersonic vehicles, reviewed in PURSUE Release 06 record DOW-UAP-D149, MHD Air Breathing Propulsion and Power for Aerospace Applications, a Defense Intelligence Reference Document of 21 November 2010 (DIRDs).
The paper says an MHD generator behind a scramjet combustor could supply high onboard power with no moving parts, but that cold-air devices ionised by electron beams are quite impractical unless ultralightweight magnets become available. It traces the Ajax energy-bypass concept to the Leninetz enterprise in Leningrad in the 1980s and calls it meaningless below at least Mach 12, and says the shock-weakening effects some Russian groups attributed to an unknown mechanism are purely thermal. Its military applications are global-strike hypersonic gliders, aeroassisted orbital manoeuvring and lift-to-drag gains it calls a game-changer, and it predicts that Russia, China and Japan could develop such technologies within several years.
A companion paper on tracking hypersonic vehicles names the same Leninetz design, the Ayaks, among hypersonic aircraft. The Laser Lightcraft paper makes its heaviest launch case conditional on MHD research.