Between High Altitude Balloons and Low Satellites Will Be Photophoretic Propulsion
by Brian Wang from NextBigFuture.com on (#6ZNP4)
NASA is working on photophoretic levitation to uase light-induced heating to create a force that lifts and propels specially designed structures in rarefied atmospheres, such as Earth's mesosphere (approximately 50-80 km altitude). This involves metamaterial plates or 3D hollow geometries (e.g., cones, spheres, or rocket shapes) with porous sidewalls that act as Knudsen pumps: light ...