In recent years, there has been keen interest in developing an air breathing plasma thruster (ABPT) for very low earth-orbit applications, typically in the 80 – 260 km range. However, there are some challenges like developing an optimum approach to efficiently ionize air in a low pressure environment. Collimator designs are often used, which introduces additional drag.
GW researchers have developed a plasma thruster for very low orbit satellites with an efficient acceleration mechanism. The thruster has a tunable electron source that is configured to provide electrons with controllable energy. There are two electrodes at entry and exit. The controller selectively controls these electrodes to accelerate positive and negative ions in the air. This is a scramjet type neutralizer-less Air Breathing Plasma Thruster (ABPT) configuration, where the incoming air is at high speed that is not decelerated, unlike with a ramjet. This potentially eliminates the complexity of using a collimator (which increases the pressure and reduces the velocity) and reduces drag.
Figure 1. Scramjet type neutralizer-less Air Breathing Plasma Thruster (ABPT)
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