On the Possibility of Using Water as a Propellant for Powerful Plasma Thrusters

Abstract

The strategy of intensive space exploration (already announced missions of creating a habitable base in the Moon's orbit, lunar bases and flying to Mars) requires the creation of "space cargo" with a powerful energy source and an electric propulsion system, as well as a sufficient amount of propellant. Achieving megawatt power levels is possible using a nuclear power plant in space and plasma thrusters a kind of plasma accelerators or with high-frequency heating in presence of a longitudinal magnetic field. Now, the most proven version is the VASIMR VX-200SS, similar thrusters are being developed in Russia. In the future, the propellant for the plasma engine needs to be replenished directly by the substances available in space, for example, using extensive water supplies. There are some encouraging results on the use of water as a propellant for powerful plasma thrusters - these are experiments with microwave heating, where the efficiency gain is about 20% compared to argon, and theoretical work on the helicon discharge, which shows that the efficiency comparable to argon should be achieved at a plasma temperature above 5 eV. Now, direct experimental confirmation of the efficiency of the helicon discharge in water vapor is required. Keywords: plasma thruster, water, helicon discharge, auto-oscillations