A photographic analysis of Mach wave radiation from a rocket plume

Abstract

At 7:30 AM on October 6, 2020 Space-X launched a Falcon-9 rocket from pad 39A at Kennedy Space Center. Photographer Trevor Mahlmann had positioned his camera in the location where the rocket would pass in front of the rising sun and took a series of images of that encounter. These images are visually stunning, but they are also scientifically useful. The high-intensity sound and shock waves originating in the plume are imaged by passing in front of the sun, particularly near the edge of the sun. This can be considered a background-oriented schlieren system. The sound from a supersonic rocket plume is thought to be due to Mach wave radiation, but the details are not yet well understood. We are analyzing these images to determine the position and radiation characteristics of the sound source in the plume. The results of this analysis will be presented.