"Ionic wind"-propelled aircraft flies with no moving parts

For decades, science fiction creators have imagined new forms of propulsion to drive space- and aircraft through the atmosphere and cosmos. Many have turned to the concept of ion drive, where a stream of charged particles is expelled from the rear of the craft and pushes it forward in accordance with Newton's third law of motion. In recent years, ion drive has become a reality for spacecraft, with six missions now using this form of propulsion, including the gravity wave detector Lisa Pathfinder and the recently-launched BepiColumbo spacecraft, which will use an ion drive in his approach to Mercury. Now, researchers at the Massachusetts Institute of Technology claim to have installed an ion drive for the first time in an aircraft.

Described in the current issue of Nature, the as-yet-unnamed aircraft would be the first ever to fly using a propulsion system with no moving parts. Resembling a large glider, the aircraft has a 5m wingspan and weighs just over 2 kg. The drive system consists of two sets of wires, stretched taut underneath the leading and trailing edges of the wings, with the front set somewhat thinner than those at the rear. These are connected to a stack of lithium-ion batteries housed in the aircraft fuselage, which in turn is connected to a lightweight power converter that supplies 40,000 V to the wires. This voltage positively charges the wires at the front of the wings, which attract and strip away electrons from surrounding molecules in the air. This creates positive ions that are attracted to the negatively charged wires at the rear of the wings. The moving ions collide with air molecules between the two wire arrays, creating a an air current known as "ionic wind" which, passing over the wings, creates a thrust that moves the aircraft forward.