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Behind the X Prize

        Science | Spaceflight

What is the Ansari X Prize?
Space Transport's Eric Meir with two-stage rocket
Space Transport's Eric Meir with two-stage rocket

So, just what is the Ansari X Prize? Simply put, it's a contest that promised a cash prize of $10 million to the first registered team to:

  • Build a spaceship able to carry three adults (height up to 188 centimeters [6 feet, 2 inches] and weight up to 90 kilograms [198 pounds] each).
  • Launch the spaceship with three soon-to-be astronauts to a height of 100 kilometers (62.5 miles), the internationally recognized altitude at which sub-orbital space begins.
  • Return the spaceship to Earth safely -- no broken bones on the astronaut, no severe damage to the ship, etc.
  • Repeat the flight within two weeks using the same ship, having replaced no more than 10 percent of the ship's parts (with the exception of fuel), thus classifying the spacecraft as a Reusable Launch Vehicle (RLV).

The feat had to be completed by January 1, 2005, so SpaceShipOne took the prize with lots of time to spare. In addition to the cash purse, the winner received a 5-foot-tall (152-cm), 200-pound (90.7-kg) bronze trophy. (See Ansari X Prize Trophy for a look at the design.)

No financial help could be accepted from any government -- this means no government grants, no government subsidies, no NASA ships and no NASA parts. There was no lack of private donors, however. The star-studded list of contributors include Microsoft co-founder Paul Allen (Scaled Composites' SpaceShipOne), the original space tourist and millionaire Dennis Tito, Charles Lindbergh's grandson Erik Lindbergh, former astronaut and U.S. Senator John Glenn, author Tom Clancy and actor Tom Hanks.

People from all countries of the world were able to compete for the X Prize, and more than 20 teams from seven countries were registered. Contestants had to submit a $1,000 registration fee along with a detailed description of the proposed vehicle and mission, and they had to agree to follow the rules and specifications above (for a look at the specific documents that were required, see Ansari X Prize: Register as a Team).