Nothing shocked the modern world more than a simple "beep, beep" sound coming from the sky emitted not by mysterious aliens, but by a small spherical object, the Sputnik, the first manmade artificial object to defy Earth's gravity and circle Earth every 90 minutes, and heralding so the arrival of the space age. It also started a fierce competition between the Soviet Union and the United States to win the race to land the first man on the moon and prove so the superiority of their repsective political system. Although 50 years ago I was still a university student, shortly after that I was a participant on the first US mission to the moon and vividly remember Neil Armstrong's famous words from the Tranquility Base on the surface of the moon: "That's one small step for a man, a giant leap for mankind". As a participant on many space missions, I will reminisce on some of them and give a sense of what it feels to land on the surface of another heavenly body, have a comet flyby, return back to Earth a comet sample material and elaborate on the successes and failures in space exploration for the last 50 years.