Skylab launched May 14, 1973, nearly died minutes later, and hosted three crews over 171 days. Built from Apollo leftovers, saved by ingenuity, lost over Australia in 1979.
The real obstacles to Mars colonization: deadly radiation, -80°C cold, toxic perchlorate dust, ISRU fuel, muscle loss, and how SpaceX's Starship plans to solve them.
SpaceX Starship: 100+ tons to orbit, Raptor methane engines, orbital refueling and ISRU on Mars. The engineering of humanity's most ambitious interplanetary vehicle.
