the v-2 would tumble in the rarefied atmosphere at high altitudes. having been designed as a weapon, the v-2 carried a large payload, approximately one ton of high explosive. this was more than was considered necessary for the scientific instrument payload of a high-altitude research rocket, but in the case of the v-2, used for research, most of the payload was lead ballast required for stable flight, limiting the potential speed and altitude that could be reached with the smaller payloads typically needed for early scientific investigations.