The X Prize is designed to help create a space industry, and is modeled after many prizes from the early 20th century that helped prod the development of air flight—notably the $25,000 Orteig Prize that spurred Charles Lindbergh to make his solo flight across the Atlantic Ocean.
The X-Prize Foundation (based in St. Louis, Missouri) maintains a list of organizations registered for the prize, which makes a good overview of the companies presently developing means of low-cost access to space. However, to maintain secrecy many companies pop up out of the blue as their requests for air space permission generate publicity; such is the case with Scaled Composites, a company that remained unknown as a competitor until April 2003. This list notably does not include traditional space access companies like Boeing and Lockheed, which many in the industry believe to be incapable of replacing their present space transportation vehicles with low-cost alternatives. These critics claim as evidence the companies' several failed attempts to do so, such as the X-33 project, on contract from NASA and other U.S government agencies. However, the X-Prize Foundation itself does not bar these companies from applying, so long as they can prove their efforts on this project would be free of government funding.
As of November 15, 2002, the X-Prize's funding will expire on January 1, 2005, so most of the competitors are planning to launch before then.
Partial list of X-Prize contestants: