Vanguard 1 Takes Off
Next: March 17, 2027
The oldest satellite still circling.
The story
Where it comes from
This Story marks the anniversary of 17 March 1958, when the US Naval Research Laboratory launched Vanguard 1, a shiny aluminium sphere just 16.5 centimetres across. Built for the International Geophysical Year, a worldwide scientific effort, it was the fourth artificial satellite ever to reach orbit and the first to run on solar power, with six small solar cells feeding its radio. The radio fell silent in the mid-1960s, but the satellite never came down. It is still up there, the oldest human-made object in orbit.
How it's celebrated
There is no formal observance, but the Naval Research Laboratory has marked its big anniversaries. On a clear evening it is a good day to step outside after dusk and watch for satellites crossing the sky, and to remember that one of the first, no bigger than a grapefruit, is still among them.
Did you know
- Vanguard 1 was about the size of a grapefruit and light enough to carry in one hand.
- Tracking its orbit helped show that the Earth bulges slightly around the equator.
- The International Geophysical Year it was built for brought together scientists from 67 nations.
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