Ariel, the first international cooperative Earth satellite, launched April 26, 1962, as a joint project of agencies of the United States and the United Kingdom. Design, construction, telemetry, and launching of the 14.5-kilogram (32-lb) satellite was handled in the United States by the National Aeronautics and Space Administration (NASA). The United Kingdom was responsible for designing the equipment and the experiments to measure electron density and temperature and composition of positive ions, intensity of solar radiation in ultraviolet Lyman-alpha line, and cosmic rays.