Hail-suppression activities are undertaken in many countries to prevent the devastating effects of hailstorms. Among various hail-suppression techniques there is overseeding, where the hail formation process is influenced by seeding the clouds with artificial nuclei. An injection of artificial nuclei into supercooled parts of the clouds can be performed by small low-altitude rockets which carry a pyrotechnic substance impregnated with meteorological reagent. The reagent produces nuclei during burning of pyrotechnic substance and injects these nuclei directly into the cloud region where the hail develops and thus prevents hail formation. This paper reports on the development of a new generation of antihail rockets, where a rocket (which consists of a motor and a container with a pyrotechnic substance) is launched from its transport tube, i.e., the transport tube represents the launcher at the same time. In addition to motor thrust, the rocket escapes the launch tube at the expense of exhaust gases produced by the motor (hot-launch system). As the rocket launch velocity increases in this way, its operation range is extended and the surface wind sensitivity of the rocket trajectory is reduced. Thereby the total mass of the propellant and the diameter of the rocket are reduced, for the same maximum altitude and mass of the reagent, as compared to the rockets propelled during launching by thrust force only. This also ensures better performance, easy handling, and reliability of use.