2002: SpaceX was founded by Elon Musk with a goal of reducing the cost of space travel thus getting humans on Mars.
2008-2015: Numerous successful tests of the Falcon 1, and Falcon 9 rockets as well as the Dragon cargo ship.
2016: Musk announces his Mars colonization plan.
2018: Send unmanned Dragon capsule to deliver cargo to Mars, as well as begin ship, booster, and orbital testing.
2022: Actual manned flights to Mars set to begin.
50-100 years down the road: Establish sustainable million person civilization on the Red Giant.