NASA will soon test a hypersonic plane cruising at Mach 7 and using turboreactors running at Mach 2.8, with the help of an engine brake MHD system. The hypersonic air bursting in at Mach 7 is slowed down at a supersonic speed (just below Mach 3) at the engines intake.
Dr Isaiah Blankson, plasma physicist and hypersonic flight specialist at NASA, tells that such a system might extract 30 to 40 % of the air kinetic energy, which would decrease the air speed from 50 to 75 %. The by-pass MHD principle also allows to reuse elsewhere the energy collected during the deceleration of the air, for example to power several systems as ionisators or MHD accelerator at the exhaust of the engines.
Studies are going to be undertaken until 2009 at the Glenn Research Center Cleveland, Ohio, on the basis of new ionisators at pulsed high voltage offering a ionisation performance of 40 % recently developed by NASA.