Juno I was an American rocket that played a significant role in the early days of space exploration. It was developed in the 1950s and was primarily used to launch the first successful American satellite, Explorer 1, into orbit on January 31, 1958. The rocket was based on the Jupiter-C design and was a modified version of the Jupiter missile. The Juno I stood about 22 meters tall and was powered by a cluster of Redstone and Jupiter engines. Its successful launch marked a pivotal moment in the Space Race between the United States and the Soviet Union, showcasing American capabilities in space technology.