NASA Rocket Takes First Multi-Point Look Inside Radio-Disrupting Clouds

High above Earth, thin veils of metallic haze known as sporadic E layers drift through the edge of space. Formed from vaporized dust of burnt-up meteors, these clouds are unpredictable in their appearance and disappearance. For the first time, a NASA sounding rocket carried five detectors through one of these layers simultaneously, revealing unexpected complexity in the layer.

Sporadic E layers impact radio signals used for long-distance communication, causing signals to bounce off in unexpected directions and making technology temporarily unreliable. Until recently, scientists had only sampled these layers one narrow slice at a time. The sporadic E Electrodynamics Demonstration (SpEED Demon) sounding rocket launched from NASA's Wallops Flight Facility in Virginia on August 24, 2022, and demonstrated the first concurrent, multi-point view inside sporadic E. The rocket was equipped with ejectable probes called dropsondes that measured plasma along their own tracks.

This multi-probe approach turned the traditional narrow crack of observation into a picket fence, providing crucial context. The data revealed an uneven and structured layer, shaped by turbulent winds and atmospheric turbulences. The layer even split into two distinct peaks, a finding consistent with modulation by Kelvin-Helmholtz billows, wave-like instabilities producing breaking-wave patterns in ordinary clouds.

Although the flight couldn't directly measure local winds and electric fields, the researchers called this explanation plausible. The SpEED Demon mission was designed as a technology demonstration to test the dropsonde technique, which proved successful. The team has since used a similar multi-probe strategy to study the upper atmosphere during solar eclipses and is planning further missions to study sporadic E layers at lower latitudes.