Ranges depend on whether you measure from the first or last flight of a program that was active over some time period.
Past achievements in space exploration:
- First US satellite in orbit to first man in space: 3 years
- First US satellite in orbit to first man in orbit: 4 years
- First man in orbit to first Moon landing: 8 years
- Moon landings to LEO space station: 1-4 years
- Moon landings to LEO Space Shuttle: 9-11 years
- Pioneer 10 to Voyager 1 and 2: 5 years
Current vision of space exploration:
- First LEO Space Shuttle to LEO space station completion: 19 years
- From LEO Space Shuttle to Moon landing: 10-29 years
- From LEO Space Shuttle to Mars landing: 17-36+ years
- Cassini to Europa Jupiter System Mission: ~10 years
Where did the ambition go?! Maybe I will help re-inject some this summer.