Arrange the following events in space exploration in chronological order. Humans orbited Earth. Sputnik I was launched into space. The first human stepped onto the moon. Explorer I was launched.

The events in the early stages of space exploration in chronological order are as follows:

Sputnik I was launched into space.

Explorer I was launched.

Humans orbited Earth.

The first human stepped onto the moon.

The main characters of the Space Age that was held at the beginning of the second half of the 20th century were the Soviet Union and the United States wherein the Soviets launched the first satellite to the outer space, but the United States were the ones that brought man to the moon.