THE EFFECTS OF CHEMICAL PROPULSION ON THE ENVIRONMENT

This paper seeks to quantify the effects of chemical propulsion exhaust on both the local launch site and the global environments. Four major areas of concern are discussed: the stratospheric ozone, acid rain, toxicity, and the greenhouse effect. The environmental impacts of both solid and liquid rocket propulsion systems are evaluated. The exhaust species and launch profile of the Space Shuttle, which injects the greatest mass of exhaust products into the atmosphere of any current system, are discussed in some detail. Model calculations predict a global stratospheric ozone reduction of about 0.01% due to chemical propulsion. Acid rain due to the HCl in solid rocket exhaust has a small measurable impact on the local environment, with the mortalities of some plants and small fish very near (<2500 ft) the launch site having been documented. Based on history, the handling of potentially toxic species from the use of chemical propulsion systems is manageable. The relative contribution of chemical propulsion to the global CO2 burden, the increase of which may lead to global warming, is insignificant. It appears that the perturbation to the natural environment caused by chemical propulsion exhaust is very small and manageable, even for the most optimistic projections of future launch rates.