The Endeavour space shuttle is hanging in the California Science Center in Los Angeles. It was the last shuttle built and its last mission was May 2011. Dr. Kenneth Phillips of the California Science Center believes that the Shuttle Program inspires the human imagination to explore new ideas including colonizing Mars.
Elon Musk founded SpaceX in 2002 with the hopes of creating lower cost space travel and colonizing Mars.
Dr. Phillips believes we should be on Mars in the 2030's.