Deployment mechanism for nanosatellite dipole antenna

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.

The Splashing of Melt upon the Impact of Water Droplets and Jets

Small-scale experimental studies of melt splashing upon the impact of water are presented here, with a focus on the fluid dynamics and thermal aspects of these interactions. Gravity-accelerated droplets and forced short-duration water jets interacted with liquid Rose’s alloy superheated to 100–200 degrees above its melting point. A repeatability study was performed for better-control of the gravity fall of a droplet. The amount of perturbation on the melt surface was obtained from a video recording, and indicated the existence of three principal stages of interaction. The cases using the forced water jet demonstrated the occurrence of a cumulative jet of melt following the collapse of the cavity caused by the water impact. Also, it was shown that numerous small-diameter melt droplets were scattered by the primary impulse, and small-scale micro-eruptions were observed, which generated small but fast melt droplets at the later stages of interaction.