This paper investigates the physics of air plasma formation at the entrance of the MHD slipstream accelerator for the ‘tractor‐beam’ Mercury Lightcraft. Two scenarios are analyzed. The first addresses the needs of the minimum power airspike assuming that all the power required for air plasma formation must come from the remote laser beam. The second case considers the constant‐focus airspike and assumes that the breakdown criteria is satisfied by an on‐board auxiliary source (e.g., electric discharge, RF source, microwave source, or E‐beam). © 2004 American Institute of Physics