1. The Economic Impact of Commercial Space Transportation on the US Economy, Futron Corporation, Federal Aviation Administration, Office of Space Transportation, Washington, DC, February 2006.
2. FAA Office of Commercial Space Transportation, 2006 Commercial Space Transportation Developments and Concepts: Vehicles, Technologies and Spaceports. January 2006. FAA, Washington, DC.
3. Federal Aviation Administration (2006). 2006 US Commercial Space Transportation Developments and Concepts. FAA, Washington, DC, available at http://ast.faa.gov
4. Federal Aviation Administration (2006). 2006 Commercial Space Transportation Forecasts. Office of Space Transportation, Washington, DC, May.
5. Futron Corporation (2002). Space Tourism Market Study, http://www.futron.com