program has given us an enormous understanding of our universe. in 1977, a pair of voyager space craft set off to explore jupiter and saturn. they have traveled further than any manmade object ever. in 1990, the u.s. launched the hubble telescope. space also brought together cold war enemies. in the year 2000, russia and american astronauts moved into the international space station cooperating for a cause to benefit mankind. in 2012, nasa's enthusiasm was contagious when a risky move to lower rover to mars worked. >> touchdown confirmed. we're safe on mars. all of these developments helped pave the way for private space companies like virgin galactic and space x and it all started when america looked to the stars