Ultrathin “Flying Disks” Could Levitate On Sunlight To Explore Earth’s Upper Atmosphere

Ultrathin “Flying Disks” Could Levitate On Sunlight To Explore Earth’s Upper Atmosphere

Near the point where the atmosphere flows into space, there is an undiscovered region known as the mesosphere or, more commonly, the ignorosphere. The air is too thin to support planes or balloons. Yet, any satellite still has enough material to excite very little. Scientists are hoping to study the mesosphere using optimistic light-flying discs (best not to call them saucers) and have now demonstrated models of this concept in the lab.

The mesosphere is not a place that “nobody has ever been before”, as every astronaut has gone through it both up and down. The problem for those willing to study its mysteries, including any impact on the climate below, is that these types of passages have always been created very quickly, with no chance to stop and explore.

Mohsen Azadi, a graduate student at the University of Pennsylvania, hopes to change that through research published in Science Progress. Azadi and colleagues created a “light field” by flashing in a chamber where the air can remove to simulate conditions at an altitude of 50-80 km (10-30 feet or 0.0001-0.0003 bar pressure at sea level). They then make 500-nanometer-thick matching disks (1/50th of a human hair) and cover the bottom with carbon nanotubes. When place in the chamber and exposed to the equivalent of sunlight, the discs warm up to 100k near the warm air.

A molecule of gas facing the disk from below communicates multiple times with the high-structured nanotubes, like a ball where the corner walls and the floor meet. At the top, a molecule will have only a single contact with the mylar. As a result, once the warmer surface is heated, it significantly reduces the impact on the gas particles that hit it and provides a higher power to the disc. The top layer of Mylar gives very little power to anything that side creating net upward powers on the disk in other words, the light levitated them.

Sunlight alone heats the discs large enough to create a strong enough effect to balance the gravitational ball on the smaller weight of the disc. Azadi and co-authors report that it should be possible to guide them even by controlling the curls of the discs. 

Although the discs need to be exceptionally light for the whole thing to work, even in their current 6-millimeter (0.24-inch) diameter format they predict they can carry payloads up to 10 milligrams. As small as this is, it may be enough to suspend a dust sensor beneath them, increasing their durability and revealing the composition of the mesosphere. Radar tracking of disks can help us understand wind patterns at this altitude, which is currently lacking in global climate models. The research could continue even at night, with lasers burning on the discs and giving a completely new meaning to “Scotty Beam Me Up”.