A thruster for exo-atmospheric vehicles with electro-thermal thrust augmentation and having internally embedded heating elements for direct contact heating of gaseous products released by a propellant, particularly hydrazine, so as to increase the Specific Impulse (Isp) of the thruster. The electrical heating elements are resistant to hydrazine products. The thruster is configured as a closed sealed chamber divided into a decomposition section upstream and a heating section downstream. At least one heating element is disposed in the heating section, directly in a mixture catalyst forming a porous bed, or within a concentric ceramic tube operative as a heat exchanger, to heat the gaseous products by direct contact. The heater indirectly heats the catalyst in the decomposition section and directly heats the heating section. The thruster is operable both in space and at sea-level gravity and barometric pressure.