Colonization of Venus
Venus's atmosphere is made mostly out of carbon dioxide, which, after filtering from sulfuric acid, can be used to grow food. Because nitrogen and oxygen are lighter than the carbon-dioxide that makes the atmosphere, breathable-air-filled balloons will float at a height of about . At this height, the temperature is a manageable ; or if we could get higher (see ).
High Altitude Venus Operational Concept
Venus is a planet with a runaway greenhouse effect, with surface temperatures and pressure of and respectively. Conventional rocket engines will not work at those pressures. Hence, human missions to Venus have historically been thought impractical, if not impossible. However, Venus has advantages for crewed travel, such as Earth-like gravity (.90 Earth gravity), an atmosphere that provides a level of protection from solar and interstellar radiation, and a much greater proximity compared to Mars.