Yesterday marked the 55th anniversary of the Sputnik launch, which sent the first artificial satellite into orbit. It was actually a fairly small satellite, about the size of a basketball, but it had a big impact. It set in motion not only the space race, but jump-started a push for education and technology development. Thanks to the giant leap of Sputnik, we now use satellites for telecommunications, weather prediction, remote sensing, and navigation, not to mention the exploration of space.
This great video shows the notable events in the past 55 years of space exploration. It was put together by NU STARS, Northwestern University’s Space Technology and Rocketry Society
As for the history of Sputnik, you can read a great article by Amy Shira Teitel on Discovery Space News about the psychology of Sputnik, and another by Clara Moskowitz on Space.com about how Sputnik changed the world.