Langley, Samuel Pierpont (1834-1906), was an American astronomer, physicist, and pioneer in aeronautics. His interest in aerodynamics (the motion of gases around a body) led him to experiment with heavier-than-air flying machines. His power-driven models made some flights of about 1/2 mile (0.8 kilometer) in 1896. The U.S. government later gave Langley $50,000 to build a passenger-carrying "aerodrome." This machine twice was launched from a houseboat on the Potomac River in 1903. Both tests failed, but one using a smaller model succeeded. The second full-size model test was made in December 1903, shortly before the Wright brothers' epoch-making flight at Kitty Hawk, North Carolina.