The F-35 is descended from the X-35, the product of the Joint Strike Fighter (JSF) program. JSF development is being principally funded by the United States, with the United Kingdom and other partner governments providing additional funding. The partner nations are either NATO members or close U.S. allies. It is being designed and built by an aerospace industry team led by Lockheed Martin. The F-35 took its first flight on 15 December 2006. This specific F-35A is painted in the Thunderbird paint scheme. The Thunderbirds are the air demonstration squadron of the U.S. Air Force (USAF), based at Nellis AFB in Las Vegas, Nevada. The squadron tours the United States and much of the world, performing aerobatic formation and solo flying in specially-marked USAF jet aircraft. The name is taken from the legendary creature that appears in the mythology of several indigenous North American cultures.