Fifty-five years ago today, the Soviet Union launched history's first artificial satellite.

Sputnik was an innocuous satellite; Soviet scientists behind the launch were just happy to successfully put the probe into orbit. But in the United States the reaction was different.

The engineering feat very quickly gave way to hysteria and paranoia. President Eisenhower initially downplayed the role of the satellite as a threat to find that he'd grossly underestimated its psychological impact. 

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The 17 months between July 1957 to December 1958 saw a peak in solar activity. Scientists around the world agreed that it was an optimal time for investigation into atmospheric phenomenon, and deemed the period an International Geophysical Year (IGY). The goal was to advance scientific understanding of the environment around the planet, and both the United States and the USSR planned to launch satellites as part of their IGY programs.

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By the fall of 1957, it looked like the Soviets would get their satellite up before the Americans launched theirs. The end of September saw the Comité Speciale de l'Année Geophysique Internationale (CSAGI) host a six-day conference at the National Academy of Sciences in Washington. Rocketry and satellite research for IGY programs took center stage, and throughout the meeting Soviets in attendance made mention that they were "on the eve" of a satellite launch.

Americans took these remarks to be little more than boastful rhetoric. But the last night of the conference — Friday, October 4 — Sputnik zoomed overhead and proved the Soviets weren't all talk. 

The immediate reaction of U.S. leaders was diplomatic. Eisenhower and members of his administration congratulated the Soviets on their accomplishment while the news reached the Soviet people with a small article in the newspaper Pravda.

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While U.S. leaders wouldn't deny the importance of this first satellite, they also recognized that Sputnik wasn't the most sophisticated piece of hardware. It was heavy, 184 pounds, but American scientists knew its size and weight was due to its primitive instruments.

The spherical satellite held a transmitter that beeped, hardware that changed the pitch of the beep depending on temperature, and batteries to run the instrument. Ham radio operators could pick up the signal as the satellite passed overhead every 96 minutes. 

But the public didn't focus on Sputnik's basic instruments; the public focused on its size. Sputnik's 184 pounds was massive compared the 3.5 pound satellite the United States was planning to launch on the Navy's Vanguard rocket. Vanguard was also a fairly simple satellite, but its instruments were smaller and more refined. No one cared. The bigger satellite was the scarier satellite.

People were worried about the beeping, too. Some thought the signal was somehow telling the Soviets the exact locations of U.S. cities. It wasn't, though that wasn't a farfetched guess; the U.S. Army had at one point at least considered using a satellite to triangulate the exact position of cities in Russia. 

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What no one failed to recognize, from White House administrators to the man on the street, was that the rocket that put the 184-pound Sputnik in orbit was far more powerful than the rocket that was going to put the 3.5 Vanguard satellite in orbit.

The 1950s Cold War mentality turned this weight disparity into one of capability, and the implications were terrifying from the American perspective. If the Soviets could launch Sputnik, what else could they put into orbit? What might soon be zooming over our heads?

That Sputnik came on the heels of a successful test flight of a Soviet intercontinental ballistic missile just a month before surely increased the sense of fear, but being clearly visible in the night sky made the satellite more ominous than a missile test on the other side of the world. People started talking about a  "missile gap" and "technology gap."

History became divided into two eras: pre-Sputnik and post-Sputnik.

Two events the following month fed the fire that Sputnik had sparked. On November 3 the Soviet Union launched a second satellite, Sputnik 2. This second launch was much more impressive. Weighing a staggering 1,120 pounds, this spacecraft was equipped with a rudimentary life support system to keep its passenger, a dog named Laika, alive. Sputnik 2 made it clear that the Soviets' launch capability exceeded the Americans', and suggested that a manned satellite would follow before long. 

A presidentially commissioned review of U.S. nuclear policies — the so-called "Gaither Report" –  warned that the Soviet Union might have a significant ICBM capability by the end of 1959, though it wasn't definitive. And although the report was classified as top secret, details and some of its conclusions were leaked to the press.

As the news spread, it fueled the sense that a missile gap existed between the two countries. This intensified the shock of the Soviet double whammy in space. The perceived missile gap turned into a very real fear and sparked the need to match then beat the Russians in space.

The race was effectively on.

Photo: The Soviet Union launched Sputnik 1 on

Oct. 4, 1957. The world’s

first artificial satellite, Sputnik 1 was a 183-pound beach ball-sized sphere

that took about 98 minutes to orbit Earth. Credit: JPL/NASA