Venus cloud sample return concept for astrobiology

Abstract

The sulfuric acid clouds of Venus are of high scientific interest due to several intriguing observations from the past decades. These observations are not fully explained with current chemical models. Manyhypotheses have been posed to date, including the presence of complex organics or microbial life in the clouds. The possibility of life is primarily supported by the biologically benign temperatures in the cloud layers and is secondarily bolstered by several unresolved cloud-layer atmospheric chemical anomalies. Here we propose that a robust search for signs of life or life itself in the Venusian aerial environment requires a sample return of the cloud particles. We propose a Venus cloud sample return mission concept by performing key trade studies, and evaluating the requirements, feasibility, and technological needs. The baseline mission concept includes a Venus entry system, a balloon for sample collection and ascent in the clouds, a Venus Ascent Vehicle to deliver samples to orbit, a Venus orbiter, and an Earth return system. We present the concept of three critical systems that are the focus of our study: cloud sample collectors, an aerial platform, and a Venus Ascent Vehicle. We found an electrostatic fog collector for low-power, high-efficiency cloud sample capture. The most significant newly identified technology gaps for near-term focused development that we uncovered are the rapid inflation of a large 7000 m3 balloon and navigation and control of the ascent vehicle in a low-visibility and turbulent cloud environment. We discuss the various technologies of the sample return mission that need focused development and have synergies across multiple types of planetary missions.