In the early morning on Saturday , February 1 , 2003 , the Space Shuttle Columbia broke up during entry . After extensive investigation of the accident and recommendations made by the Columbia Accident Investigation Board , President Bush gave the vision for space exploration for NASA , which include return the Space Shuttle to flight as soon as practical , complete assembly of the ISS by the end of the decade , initiate robotic missions to the moon no later than 2008 , develop a new Crew Exploration Vehicle , conduct first robotic , then human missions to Mars and extend human exploration across the solar system .