The paper focuses on the design of the deployment mechanism for a nanosatellite with a fusible element. The main requirements for this mechanism were: relative simplicity of design, reliability, as well as simplification of the ground testing procedure. Using the principle of fixation on fusible elements, Rose’s alloy in particular, we designed a laboratory prototype of the antenna feed deployment mechanism for CubeSats. Furthermore, we developed a technology of flap deployment control by measuring the conductivity of the fusible element. We carried out a set of tests of the created laboratory prototype on a vibration stand and in a thermal vacuum chamber, as well as a series of functional tests. Comparison of the created prototype with the closest commercial analogs showed that a significant gain in the dimensions of the structure was achieved, as well as the number of elements of the mechanism itself was reduced, which positively affect reliability.