- Sputnik 1
Russia stunned the world in October 1957 when it announced it had placed the first man-made object in orbit around the Earth, the basketball-sized Sputnik 1.
- Explorer 1
America replicated the success of Russia three months later when it launched its first satellite, Explorer 1, which discovered the belts of radiation around Earth.
- Echo 1
NASA launched this giant balloon, 30 metres in diameter, in 1960. It reflected incoming signals and was the world’s first rudimentary communications satellite.
Developed by RCA Americom, Satcom 1 (launched 1975) pioneered US cable TV broadcasts with high-profile networks and spurned the age of satellite TV.
Construction of the world’s largest man-made satellite began with the launch of the Zarya module in 1998, and is scheduled for completion in mid-2012.