A floating habitat on Venus is actually more attractive. Venus (upper atmosphere): -human livable temperatures with modest temperature control -Earth-like pressure (Himalayans) leads to slow leaks that can be patched, and pressure can be increased inside to stop the leaks inward -protected by thick atmosphere from radiation, meteors, asteroids -strong magnetic field against radiation -atmosphere still thin enough for solar panel energy use -the sulfuric acid atmosphere requires a Teflon coating and/or mixing Teflon particles with the metals during fabrication -the escape velocity from the upper atmosphere is low and requires a small rocket and not much fuel, leaving more fuel for return trips -distance between Earth and Venus is 3 months, versus 6 months to a 1 year depending on the window of opportunity.. that means you can rescue crews faster, get them supplies quicker, and replace crew sooner on Venus -oxygen on Venus has a strong lifting power, you can float entire heavy concrete and steel cities on massive platforms, think cloud city from Star Wars(tm) -aerodynamics work similarly to Earth; airships (dirigibles), airplanes, drones are all possible here Concept mission to Venus compliments of NASA: https://www.youtube.com/watch?v=0az7DEwG68A

Mars: -inhospitable temperatures not suitable for human or plant life -explosive decompression due to a micro-meteorite causing a hole -no atmosphere to protect against radiation or projectiles -weak magnetic field providing no protection -violent unpredictable wind storms on the surface -unbreathable atmosphere -the escape velocity from Mars requires a massive rocket equivalent to the one we use to leave Earth and therefore more fuel leaving less payload for delivering other resources or supplies -the distance is 6 months to 1 year depending on the window of opportunity, leading to some NASA scientists to suggest we should find it acceptable that it as a suicide mission with no hope of return

Rotating space station: -high risk from impacts -no atmosphere to protect against radiation or projectiles -no magnetic field providing no protection -danger from space debris from previous missions -no surrounding breathable atmosphere -close distance makes resupplying and re-crewing more tenable -requires constant fuel and attention to not de-orbit -does not establish a permanent residence -not a base of significant distance for further operations to the rest of the solar system