Answer: The launch of Explorer 1, the country's first satellite
Explanation: One of the most significant successes of the US rocket program was the launch of Explorer 1, the country's first satellite, in 1958. This was followed by a series of other successful satellite launches, as well as manned space missions and unmanned missions to explore the moon and other planets.
Ultimately, the US rocket program was a remarkable success, culminating in the historic landing of astronauts Neil Armstrong and Edwin "Buzz" Aldrin on the moon in 1969. The US continues to be a leader in the field of rocketry and space exploration to this day, with ongoing missions to explore the solar system and beyond.