Measurements of cloud nuclei in the effluents from launches of liquid- and solid-fueled rockets
Airborne measurements of two types of cloud nuclei, cloud condensation nuclei (CCN) and ice nuclei (IN), were conducted in the stabilized ground clouds which resulted from the launches of a liquid-fueled ATLAS/Centaur rocket and a solid-fueled TITAN III rocket. Results show that the concentrations of CCN in both types of clouds were greater than ambient values for the 2 hours duration of the measurements. The initial production of CCN active at 0.5% supersaturation in the ATLAS and TITAN clouds was found to be equivalent to a 20 and 700 sec emission, respectively, by the city of Denver, Colorado. After the initial production, the clouds continued to generate CCN at a rate of about 1/cu cm sec. However, concentrations of IN in the ATLAS cloud were greater than ambient values for only a short period after launch, and it appears that the nuclei resulted from entrained launch pad and ground debris. The concentrations of IN in the TITAN cloud were found to be at or below ambient levels until about 2 hours after launch when they increased substantially above ambient values.