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IntroductionThe first-ever artificial satellite took to the skies on Oct. 4, 1957.
The launch of that craft, the Soviet Union's Sputnik 1, kicked off the space age and the Cold War space race, the latter of which peaked when Apollo 11 astronauts Neil Armstrong and Buzz Aldrin stepped onto the surface of the moon in July 1969.
Here are a few fun facts you may not know about Sputnik 1 and its brief but world-changing mission. [Sputnik 1, Earth's First Artificial Satellite (Photos)]
Sputnik 1 was the size of a beach ballSlide 2 of 16
Sputnik 1 was the size of a beach ballSputnik 1 weighed 184 lbs. (83 kilograms) and was 23 inches (58 centimeters) wide. (This measure refers to the satellite's body; Sputnik 1 also featured two double-barreled antennas, the larger of which was 12.8 feet, or 3.9 meters, long.)
So, the satellite was quite small compared to the spacecraft of today, such as NASA's Cassini Saturn orbiter, which was about the size of a school bus. But lofting something as heavy as Sputnik 1 was quite a feat in October 1957. Two months later, the United States tried to launch its first satellite — the 3.5-lb. (1.6 kg) Vanguard Test Vehicle 3 (TV3) — and failed.Slide 3 of 16
The Soviet Union had been aiming biggerSlide 4 of 16
The Soviet Union had been aiming biggerSoviet space officials had wanted the nation's first satellite to be much bigger than a beach ball. The original plan called for lofting a nearly 3,000-lb. (1,400 kg) craft outfitted with a variety of scientific instruments.
But development of this satellite, code-named "Object D," progressed more slowly than expected, and Soviet officials grew increasingly worried that the United States might beat them to space. So, they decided to precede the launch of Object D with a "simplest satellite," or "prosteishy sputnik" in Russian. Indeed, Sputnik 1 was also known as PS-1, Anatoly Zak noted at RussianSpaceWeb.com. (The literal translation of "sputnik," by the way, is "traveling companion.")
Sputnik 1 carried no scientific instruments. However, researchers did learn some things about Earth's atmosphere by studying the beep-beep-beep radio signals emitted by the satellite.
The hulking Object D reached orbit as Sputnik 3 in May 1958, six months after Sputnik 2, which famously lofted a dog named Laika.Slide 5 of 16
The launch almost failedSlide 6 of 16
The launch almost failedSputnik 1 came perilously close to suffering the same fate as the United States' TV3 satellite, which was destroyed in a launch failure on Dec. 6, 1957.
Sputnik 1 was lofted by an R-7 rocket, which consisted of four first-stage boosters — known as Blocks B, V, G and D — strapped onto a core second stage (Block A). During the launch, the Block G booster's main engine reached its intended thrust levels later than expected.
"As a result, 6.5 seconds after the launch, the rocket started to pitch, deviating around 1 degree from the nominal trajectory 8 seconds after the liftoff," Zak wrote. "In the effort to correct the increasing pitch angle, steering engines No. 2 and [No.] 4 on the core stage rotated as much as 8 degrees; similar engines on strap-on boosters of Block V and D rotated as much as 17-18 degrees, while tail air rudders rotated 10 degrees.
"Only a split second remained, after which the flight control system would terminate the flight of the underpowered rocket," he added. "Fortunately, the engine finally reached normal performance, and [the] rocket fully returned to nominal trajectory some 18-20 seconds after the liftoff."
Sputnik 1 eventually settled into an elliptical orbit, which took the satellite as close to Earth's surface as 142 miles (228 kilometers) and as far away as 588 miles (947 km). The satellite zipped around Earth every 96 minutes.Slide 7 of 16
Its mission was briefSlide 8 of 16