Where in the solar system do we have Earth-like gravity, atmospheric pressure, density and radiation protection? The place that is most like the Earth is Venus 50,000 meters.
This means that we can blimps and build cloud cities for colonization on Venus. NASA had designed a blimp mission to explore the upper atmosphere of Venus.
A lighter-than-air vehicle could carry either a host of instruments and probes, or a habitat and ascent vehicle for a crew of two astronauts to explore Venus for up to a month. Such a mission would require less time to complete than a crewed Mars mission.
A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus’s atmosphere.
Key technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. With advances in technology and further refinement of the concept, missions to the Venusian atmosphere can expand humanity’s future in space.