Which year marked the launch of the first satellite?

The correct answer is 1957 because this year marked a significant milestone in space exploration with the launch of Sputnik 1 by the Soviet Union on October 4. Sputnik 1 was the first artificial satellite to orbit the Earth, and its successful deployment initiated the space age and the broader exploration of space. The event not only showcased advancements in technology and science but also intensified the space race during the Cold War era, influencing international relations and scientific endeavors in the years to come.

While 1956, 1958, and 1959 are years that saw various developments in space technology, none of them had a satellite launch that predates or compares in significance to Sputnik 1. For instance, 1958 is notable for the launch of Explorer 1, the United States' first satellite, and 1959's developments included the beginning of lunar exploration; however, the actual first satellite launched into orbit was firmly in 1957.