1) Orders of magnitude cheaper, faster and more reliable travel in both directions. 2) Ability to recreate Earth-like conditions including gravity, atmosphere,

1) Orders of magnitude cheaper, faster and more reliable travel in both directions. 2) Ability to recreate Earth-like conditions including gravity, atmosphere, sunshine, farming and raising livestock on a massive scale (hundreds of square kilometers) on Mars. 3) Ability to create adequate conditions for the transport phase. 4) Ability to justify the investment (most issues on earth solved, remember opportunity cost).