The Destiny module is the primary operating facility for U.S. research payloads aboard the International Space Station (ISS). It was berthed to the Unity module and activated over a period of five days in February, 2001. Destiny is NASA's first permanent operating orbital research station since Skylab was vacated in February 1974. Astronauts work inside the pressurized facility to conduct research in numerous scientific fields. Scientists throughout the world will use the results to enhance their studies in medicine, engineering, biotechnology, physics, materials science, and Earth science.