Terraforming Venus, and Similar Planets, using a Pneumatically Supported Shell Author: Kenneth Roy, P.E,, Retired, TVIW Abstract Background: Venus is a terrestrial planet having a hot, thick atmosphere of mainly CO2. Various ideas have been proposed to terraform the planet into an Earth-like world but the scale of the effort is immense and the results are generally considered to be unsatisfying. The main difficulties involve removing or modifying the thick atmosphere, cooling the planet, adjusting the spin of the planet, protecting the planet from solar flares and solar radiation, and dealing with the long-term effect of a thick crust devoid of plate tectonics. These efforts, baring some magical technologies, will require time frames measured in tens or even hundreds of millenniums. A new, previously unpublished approach (to the best knowledge of the author) toterraforming Venus that avoids most of these issues is discussed in this paper. This is relevant to interstellar colonization because Trappist-1 has several planets that seem to be terrestrial with thick hot atmospheres, indicating that such planets may be very common around K and M class stars. If it is possible to terraform Venus using this approach with a time frame of one or two millennium then this approach should be workable for many other similar planets allowing for human expansion into the Galaxy. Abstract Objectives: This paper examines the possibility of constructing a material shell in the Venusian atmosphere at an altitude of approximately 40 kilometers above the surface using Venusian materials. The building blocks of this shell are brought to altitude using buoyancy of a large vessel containing oxygen and nitrogen gases similar to Earth’s atmosphere. Their shape and design are based on Geodesic Sphere theory. These building blocks can then be used as floating cities until enough of them have been positioned to create a solid Geodesic spherical shell. These building blocks are then lowered a few kilometers and a solid continuous shell is established as the building blocks are welded together. At that point gas processing begins where the atmosphere above the shell is separated into its components and oxygen and nitrogen (Venus has a lot of nitrogen) are released above the shell and most CO2 is compressed and released below the shell. Over time (estimated at about a millennium) the atmosphere above the shell is adjusted to Earth-normal composition with nitrogen, oxygen, and argon and Earth-normal pressures. The technology needed for the processing of atmospheric gases can be used to extract nitrogen and helium from the Venusian atmosphere. Nitrogen is useful for other terraforming operations throughout the solar system and helium production suggests He-3 availability on a fairly large scale. The pressure below the shell supports the shell and as been demonstrated in previous works, is stable. The shell is entirely supported by the Venusian atmosphere and not connected to the planet’s surface in any way. The original Venusian atmosphere is mostly unmodified and available for future use. The shell itself can rotate independently of the planet and can be spun up to duplicate Earth’s axial tilt and the 24-hour day night cycle. A device located at the Sun-Venus L1 point is discussed that can reduce the solar constant at the planet to Earth levels, or even lower, and can also supply energy to the planet using beamed energy. This device can also support magnetic fields to deflect solar particles away from the planet. Abstract Methods: A Spreadsheet is used to validate the approach and to quantify significant values. Abstract Results: A spreadsheet examines a number of the parameters necessary for this approach and concludes that materials and technologies available in the near term make this terraforming idea viable. However, a vibrant interplanetary society is required to provide the resources for this project. The resulting habitat will have near Earth gravity, a good view of the stars, a shirt sleeve environment for humans and plants. Oceans cannot be accommodated with this approach but, small shallow seas, lakes, rivers, and canals are possible. It also has an area in excess of three times the land area of Earth. And it has the planet Venus just a few kilometers away to support industrial and mining operations. There are open questions relating to the contained atmosphere under the shell and how it might react to lack of solar input. The heat transfer issue at and within the shell is considered but not evaluated in detail assuming that insulation and active cooling systems will be required. Abstract Conclusions: A significant effort will be required but Venus can be terraformed into a very Earth-like environment on the shell above the planet’s surface using near-term technologies and materials. This could serve as a template for later interstellar terraforming efforts.