It has no moving parts like a propeller or a turbine engine, which is especially unusual for an aircraft. Instead, the plane is kept in flight by an ionic wind system. The thrust it needs to fly is provided by colliding electrically charged air molecules. To overcome this obstacle, the MIT test aircraft carries an array of thin wires strung beneath the front end of its wings. A high voltage current passed through the wires via a lightweight power converter strips negatively charged electrons from surrounding air molecules.