When we hear the term "flying saucer", we immediately think of the spacecraft used by aliens in various science-fiction stories and films. But scientists and engineers at the Massachusetts Institute of Technology (MIT) have developed a flying saucer of their own design to conduct research on the moon. The interesting thing is that the saucer will use electrostatic repulsion to hover over the surface of the Moon.
Because the Moon has no atmosphere to defend itself, its surface is continuously bombarded by blasts of cosmic particles and ultraviolet radiation from the Sun. The vast majority of particles are positively charged and throughout its existence the Moon has accumulated a relatively strong positive potential. Due to this potential, lunar dust illuminated by the Sun can rise up to 1 metre above the surface, through the same effect that would make our hair stand on end when combing it with a plastic comb.
The idea of using electrostatic potential to fly over the surface of the Moon is far from new. Some time ago, a 'lunar electrostatic glider' project with wings made of mylar and powered by an artificial positive potential was proposed. The repulsive forces of equally charged objects are supposed to keep the glider above the surface of the Moon.
According to calculations conducted by experts from MIT, such a trick could only work on small asteroids, because the Moon has a strong enough gravity that would not allow the "lunar glider" to fly. But a flying vehicle that artificially amplifies electrostatic repulsion forces would be able to use this principle to enable flights over the surface of the Moon.
The structure of the lunar 'flying saucer' contains a device which generates two ion streams. A stream of negatively charged ions is directed into space, giving the saucer itself a positive electric charge. The second stream of positively charged ions is directed downwards towards the surface and is designed to increase the electrostatic repulsion forces in a local area of the surface.
The ion fluxes are created by miniature ion engines that use different types of fuel (melt of certain salts). Note that exactly the same engines are already used in miniature artificial satellites such as CubeSats.
To obtain proof of the feasibility of such a method, scientists conducted an experiment. A model of a "flying saucer", weighing 60 grams and as big as a human palm, was suspended on springs over an aluminium surface in a vacuum chamber. The springs simulated the reduced gravity of the moon and also measured electrostatic repulsion forces. The flux of negative ions was produced by one upward-facing ion engine, while the four downward-facing ion engines produced fluxes of positive ions.
During the experiment, it was found that a small enough power source to power the ion engines was enough to lift the 'flying saucer' one centimetre above the surface of the Moon. However, even higher altitudes are possible, but the power supply would have to be increased many times over because electrostatic repulsion decreases with distance according to the quadratic law. Nevertheless, the technology could already be used to conduct research on asteroids and other low-gravity space bodies.
