In the past few years the possibility of the space travel to Mars in the beginning of XXI century has been discussed. The main problem is the choice of an engine. Now, the primary engine is a chemical rocket engine with an exhaust gas velocity C of about 1 km/s. Such an engine is suitable for a rocketed space automatic station but is of little use for a Mars-earth return spacecraft. For a man-carrying spacecraft the jet velocity must be of about Earth orbital velocity Ve ≃ 30 km/s. The aim of this paper is to discuss the possibility of electrodynamic plasma accelerators for use as a main rocket engine with high jet velocity.