Human Space Flight Independent Investigation Commission Act of 2003 - Directs the President to establish an independent, nonpartisan commission within the executive branch to investigate and report to the President, Congress, and the public on any accident or deliberate act that results in the loss of: (1) a space shuttle; (2) the International Space Station or its operational viability; (3) any other U.S. space vehicle carrying humans; (4) any space vehicle carrying U.S. citizens; or (5) a crew member or passenger of any such space vehicle. Requires the President to issue an executive order establishing such a commission within seven days after such an incident.
Requires the National Transportation Safety Board to: (1) assume responsibility for investigation of such an incident immediately after its occurrence; and (2) transfer investigative responsibility to such a commission as soon as the commission holds its first meeting.