Analytical review of development of aerostatic probes for Venus

Considered are projects of balloons for expeditions in Venus atmosphere, as well as publications on development and successful launch of balloons from descent vehicles VEGA 1, 2 in Venus atmosphere. Based on the analysis of project publications a classification of balloon schemes is proposed, and design solutions and schemes for maintaining and changing the floating altitude of the balloon using buoyancy control and propeller control are presented. Described are design solutions for a number of balloon projects for Venus exploration. Several balloon projects for navigating at low altitudes, and carrying and launching from a balloon at an altitude of more than 50 km above the surface of the return rocket for delivering soil and atmosphere samples to the Earth are considered. Design characteristics including estimation of mass, dimensions, altitudes being maintained and floating duration of the proposed balloons in Venus atmosphere are discussed. Design solutions with regard to maneuverability in Venus atmosphere with respect to complexity of their implementation are assessed. The progress trends in development of Venus balloons are evaluated.