The Centennial Challenges are based on a long history of technology prize contests, including the Longitude prize (won by John Harrison), the Orteig Prize (won by Charles Lindbergh), the Ansari X PRIZE (won by Scaled Composites), and the DARPA Grand Challenge (won by Stanford University in 2005 and Carnegie Mellon University in 2007). A key advantage of prizes over traditional grants is that money is only paid when the goal is achieved. A 1999 National Academy of Engineering committee report recommended that "Congress encourage federal agencies to experiment more extensively with inducement prize contests in science and technology". A 2003 NASA Space Architect study, assisted by the X PRIZE Foundation, led to the establishment of the Centennial Challenges.