The shock of Sputnik, launched 50 years ago today, propelled the United States to land men on the moon. DAVID ABBOU

How has the space race changed in the 50 years since Sputnik?

Date published: 10/4/2007

ON AN October day 50 years ago, the world changed forever. The space age began as the Soviet Union successfully launched the Sputnik 1 satellite into orbit on Oct. 4, 1957.

The satellite did not make any new discoveries about the Earth or the universe, but its reverberations were felt throughout the world.

The satellite carried a radio transmitter that transmitted constant beeping tones heard by radio operators on Earth. More than anything, hearing those beeps probably served as a reminder that our Cold War foe, the Soviet Union, had beaten us in the opening chapter of the space race.

I can imagine how Americans felt when Sputnik was launched. Knowing it was orbiting the Earth every 96 minutes or so, I am sure most citizens felt some sort of fear or insecurity as it passed overhead. Was it a device meant to spy on us, or was it some sort of Soviet space weapon?

Of course, Sputnik was neither of those, but the 184-pound satellite shocked the United States into a sense of urgency as the groundwork for the space race was laid.

America's answer to the Soviet's first satellite came on Jan. 31, 1958, with the successful launch of Explorer I, a small satellite that discovered Earth's radiation zones.

As a direct result of Sputnik's launch, the National Aeronautics and Space Administration was created in October 1958.

In July 1969, almost 12 years after the initial shock of Sputnik, the United States made what is arguably the greatest technological achievement of the 20th century, landing Americans on the moon and returning them safely to Earth. For once, we beat our foes at their own game, but did it really matter?

More than three years later, in December 1972, the last Americans left the lunar surface as the United States' interest in the space program waned. No human has set foot on the moon since.

Today, 50 years after Sputnik, what have we learned about exploring the universe?

For one thing, space exploration must be conducted for the right reasons. Racing to space to achieve military or political dominance may engage the public for the short term, but those reasons will not justify serious, long-term objectives.

Date published: 10/4/2007