Ariel 1 (also known as UK-1 and S-55), was the first British satellite, and the first satellite in the Ariel programme. Its launch in 1962 made the United Kingdom the third country to operate a satellite, after the Soviet Union and the United States. It was constructed in both the UK and the United States by NASA Goddard Space Flight Center and SERC, under an agreement reached as the result of political discussions in 1959 and 1960. The US Starfish Prime high-altitude nuclear test affected Ariel 1's operational capability.