Acoustical measurement and analysis of an Atlas V launch

In September 2021, an Atlas V rocket without solid rocket boosters was launched from Vandenberg Space Force Base, California, carrying the NASA/USGS Landsat 9 satellite. In this launch configuration, the plumes from the RD-180 engine’s two nozzles are unobstructed, providing the opportunity to analyze the sound generated by a liquid-fuel rocket engine with an azimuthally asymmetric nozzle geometry. Acoustical data were collected at various locations surrounding the launch pad, ranging from a few hundred meters to several kilometers. This paper discusses an overview of the measurement logistics, maximum overall sound pressure levels at the measurement stations, and an initial analysis of the azimuthal variability of the overall sound pressure level and spectra along two radials. Within the constraints of this measurement, the Atlas V radiation does not appear to be azimuthally asymmetric.