Before travel is actually possible and life sustainable on any foreign body, the atmosphere has to be perfected.

At 6:31pm, (click here) Roger Chaffee reported “Fire, I smell fire.”  Seconds later, Ed White exclaimed, “Fire in the Cockpit.”  Several other voice transmissions included “They’re fighting a bad fire—let’s get out.”  “Open’er up.”  “We’re burning up….”  The last transmission ended within 17 seconds after the first report of the fire.  Grissom, White, and Chaffee perished within 30 seconds due to smoke inhalation and burns....

I am sure the International Space Station has addressed all that, but, changing a planet's atmosphere is quite different. Pure oxygen environments do not sustain life. That has to be perfected before life is viable anywhere else, but, Earth.