It was a Cold War propaganda machine, launched for reasons of pride, territoriality, greed, and a passel of other human failings, but it also separated all of history into Pre Space Age and Post Space Age.
No one thought the Soviet Union could do it, but on October 4, 1957 at 19:28:34 UT, they launched Sputnik, the very first artificial satellite into Earth orbit. The shock of this -- Red Star in Orbit! -- motivated the Space Race, and in just 12 years put men on the Moon.
Sometimes, out of bad comes good.
Your life depends on satellites in more ways then you might know. Weather forecasting? Check. Communications? Check. GPS? Internet? Intelligence Ops (which prevent wars, mind you)? Yup.
Don't forget astronomy! Oh no, don't you dare forget that: Hubble, Chandra, Spitzer, SOHO, Swift, Uhuru, Einstein, COBE, WMAP... these all revolutionized our understanding of the Universe, in more ways than can be easily recounted, and they're all satellites.
I am still amazed that most folks don't know that they can easily see satellites on any clear night. Got to Heavens Above. Enter your coordinates. Then find out when the ISS passes overhead, or a rocket booster, or Hubble. Please, go look for Iridium satellites! They'll rock your world.
In the mean time, read up on the littlebasketball beachball-sized doohickey that changed the world, and humanity, forever.
- Fraser wrote an interesting article on Wired about the sons of Sputnik; the satellites we have up now.
- The official NASA history of Sputnik, which is very sparse and a little boring. They have a better one here. Tom's Astronomy Blog entry is pretty good, too.
- The Wikipedia entry for Sputnik is actually pretty entertaining.
- Did people really see Sputnik, or just the second stage booster? Here's an interesting backstory of Sputnik, claiming that what we thought we knew about it was wrong.
Update: What was I thinking??? I forgot to add: On this date, just three years ago, SpaceShipOne rocketed to an altitude of 100 km above the ground for the second time in a week, winning the X-Prize. It was the first private spaceship to do so. Tip o' the nosecone to Dispatches from the Final Frontier for reminding me.