Sara Seager
MIT
We propose to study a Venus sample return mission focused on the atmosphere—both the gas component and up to 1 g of cloud particles. The mission goal is to bring back the sample for Earth-laboratory-based study to assess the habitability of the cloud-region of the atmosphere and search for signs of life or even life itself in a much more robust way than possible in situ. Earth laboratories have a wider variety of equipment that may reach more sensitive levels of detection as compared to in situ space-based instruments. For decades people have speculated on Venus as a habitable world via its temperate cloud layer. Despite unique environmental challenges of the clouds, e.g., extremely low water content and the presence of concentrated sulfuric acid, long-standing and unexplained atmosphere measurements, as well as new findings and recent modeling, support the speculative idea that Venus may indeed be inhabited by microbes in an aerial biosphere. Despite renewed interest in Venus via two NASA and one ESA mission to launch in the late 2020s, astrobiology is not a focus. The proposed mission concept has a two-component flight system, an entry probe and orbiter. The entry probe consists of a variable-altitude balloon operating between 45-60 km altitude above the surface. The balloon’s gondola contains the sample capture hardware, as well as the ascent launch vehicle. After spending a few days capturing samples from different atmosphere locations, the aerial platform will rise to about 70 km altitude, the ascent vehicle would launch and rendezvous with the orbiter, followed by return to Earth and sample container recovery. The search for life in the Venus clouds and by atmosphere sample return matches the solicitation objectives as it is an “exciting, unexplored, credible aerospace concept.” The proposed concept is applicable to any solar system bodies with atmospheres. The proposed effort supports NASA’s goal to expand human knowledge through new scientific discoveries and NASA’s mission to “Drive advances in science, technology, and space exploration to enhance knowledge” (2021 mission statement). In addition, our proposed mission would directly address NASA SMD’s mission to “Search for life elsewhere” (2020-2024 NASA Science Plan).