Capillary-porous electrodes for plasma MHD devices are considered. The electrodes can be continuously renewable and allow one to use a scheme of the inverted MHD generator (i.e., MHD accelerator) as a thruster for interorbital flights. Two types of plasma acceleration are considered: (i) Lorentz force acceleration with a primary current perpendicular to the acceleration direction (Faraday scheme) and (ii) acceleration based on the Hall effect. In the first case, the thruster has advantages only at thrust powers exceeding 1 MW, while in the second case, the thrust and specific impulse are comparable with those of the known analogs (or even surpass them) already at powers of 500-1000 kW. The operating conditions of capillary-porous electrodes are formulated.