The environment near the surface of airless bodies (asteroids, comets, Moon) is electrically charged due to Sun’s photoelectric bombardment. Charged dust is ever present, even at high altitudes (dust fountains), following the Sun’s illumination. We envisage the global scale exploration of airless bodies by a gliding vehicle that experiences its own electrostatic lift and drag by its interaction with the naturally charged particle environment near the surface. This Electrostatic Glider (E-Glider) lifts off by extending thin, charged, appendages, which are also articulated to direct the levitation force in the most convenient direction for propulsion and maneuvering. It thus carries out its science mission by circumnavigating the small body, and it lands, wherever it is most convenient, by retracting the appendages or by thruster/anchor.
Around airless bodies, the objects in space that range in size from asteroids to either small moons or large space stations, you can reliably find a sort of haze of dust, caused by the solar wind as well as solar illumination imparting energy to the surface which results in dust particles “fountaining” up. This energy transfer also causes the dust to become electrically charged, with the illuminated side of the body exhibiting a positive surface potential and the dark side of the body accumulating electrons which results in a negative surface potential. The terminator (the area between the dark side and illuminated side) can have an electrical potential of several hundred kilovolts per meter, while on average, the surface of an asteroid could exhibit electric fields of around 1 kV/m.
Usually, dusty and variably electrically charged environments are something that spacecraft do their absolute best to avoid, but JPL thinks that there may be a way to leverage this kind of environment to propel a spacecraft. A field of 1 kV/m has enough electrical potential to “lift” a small vehicle weighing about one kilogram. The vehicle would use 1-meter-diameter metal “wings” for electrostatic (rather than aerodynamic) flight, articulating them to move through ambient electrostatic fields. The energy to do this comes from the solar wind by way of whatever body the vehicle is next to, giving the craft maneuvering fuel that won’t run out until the sun shuts down (at which point you likely have bigger problems).
SOURCES – NASA, NIAC, Quadrelli, IEEE Spectrum