Abstract: Existing spacecraft accelerate by ejecting propellant, and VTOL craft hover by creating violent downdrafts of air. We describe a propellantless propulsion system that can achieve practical spaceflight and hovering flight by exchanging momentum with normally unobservable quantum particles that pervade all of space. High-polarizability nanoparticles with electromagnetic resonances in the petahertz range are formed into nanoantennas, and exposed to high fields in the terahertz range. The fields increase the density of naturally occurring vacuum fluctuation (VF) petahertz oscillations in the nanoantennas. The nanoantennas are assembled into arrays, such that their naturally occurring zero-point oscillations are amplified by the terahertz fields, producing enhanced oscillations in VF densities during each petahertz oscillation period that interfere constructively in the intended direction of emission.