The distribution of hydrogen chloride in the cloud was analyzed as a function of launch pad geometry and rate of rise of the vehicle during the first 24 sec of burn in order to define neutralization requirements. Delivery systems of various types were developed in order to bring the proposed chemical agents in close contact with the hydrogen chloride. Approximately one-third of the total neutralizing agent required can be delivered from a ground installed system at the launch pad; concentrated sodium carbonate solution is the preferred choice of agent for this launch pad system. Two-thirds of the neutralization requirement appears to need delivery by aircraft. Only one chemical agent (ammonia) may be reasonably considered for delivery by aircraft, because weight and bulk of all other agents are too large.
