Space Exploration  From Sputnik to Mars
Space exploration is the practical side of astronomy  actually sending instruments and humans beyond Earth. It tests materials, trains engineers and returns unique scientific data.
Milestones
- 1957  Sputnik 1, the first artificial satellite.
- 1969  Apollo 11 Moon landing.
- 1977  Voyager 1 and 2 begin the grand tour.
- 1998  International Space Station assembly starts.
- 2012+  Mars rovers (Curiosity, Perseverance) and sample-return missions.