 In late 2002 and early 2003, NASA astronaut Don Pettit, part of International Space Station Expedition 6, constructed a barn door tracker using spare parts he had accumulated from around the space station, permitting sharper high resolution images of city lights at night from the ISS.A simple single-arm barn door tracker can be made by attaching two pieces of wood together with a hinge.A camera is mounted on the top board, usually with some sort of ball joint to allow the camera to be pointed in any direction.