The use of rockets as delivery systems for artificial ice nuclei in modern cloud modification programs has been an important part of the developing technology for more than 30 years. The use in the United States has been limited to a few small scale operational efforts in such areas as Colorado and Utah, and in one major research program, the National Hail Research Experiment in Colorado. However, cloud seeding rockets have found extensive program use in countries such as Argentina, Bulgaria, China, France, Hungry, Italy, Switzerland and Yugoslavia. The most impressive rocket effort in both operation and research has been in the Soviet Union. The major research program designed to test the efficacy of Soviet rockets to suppress hail damage is Grossversuch IV. This has been a collaborative program, coordinated the Institute for Atmospheric Physics of ETH in Zurich, Switzerland, and included the participation of the universities and government agencies of France, Italy and Switzerland. The objective has been to test whether a hail suppression method similar to the one proposed by scientists in the Soviet Union can successfully be applied in Central Europe. Since 1970, Dr. Bruno Federer was the able leader of the program and through the years developed an international reputation as a dedicated and enthusiastic scientist. The cover photographs show examples of the rocket activity under Dr. Federer’s direction during the Grossversuch IV program. Photographs by Thomas J. Henderson, Atmospherics Incorporated.