Harvard University scientists have created a lightweight, disc-shaped device capable of levitating in the mesosphere (48 to 96 kilometers above sea level) using only the energy of light. This technology opens up new opportunities for studying inaccessible layers of Earth's atmosphere and could be used for Mars research.
The mesosphere remains one of the least explored regions, inaccessible to aircraft and balloons and too high for satellites to reach. The device uses the principle of photophoresis: at low pressure, gas molecules repel heated surfaces more strongly, generating lift.
Due to the lightweight structure, this effect is sufficient to anchor the device in the mesosphere. The device was constructed using a thin ceramic membrane made of aluminum oxide and a low chromium layer, which effectively absorbs sunlight.
In tests conducted in a low-pressure chamber simulating mesosphere conditions, a disc-shaped object with a diameter of 1 cm was able to float at a pressure of 26.7 Pa—similar to an altitude of approximately 60 kilometers—when illuminated by an LED or laser with an intensity of only 55% that of sunlight.
The technology could be used in climatology, by placing wind, pressure, and temperature sensors directly in the upper atmosphere, as well as in telecommunications, for example by creating networks of hovering antennas. In the future, such devices could even be used to study other planets.
