50 years ago, the Soviet Union launched the first artificial satellite, Sputnik 1, into orbit.

Novosti agency photo of Sputnik 1’s launch via spacetoday.org
A half century later, we have landed rovers on Mars, parachuted instruments onto the oven-baked surface of Venus, and put others in orbit around Jupiter and Saturn.
Humans haven’t been out further than the Moon, but our space probes own the Solar System. All that started back in 1957. To everyone building, flying, designing and managing unmanned spacecraft, thank you.
