Space Exploration Question!?

Well one of the things you could look is cost and enormous resources it requires to launch such a mission. Travel time to really make any advancement is is very long 4 days to the moon 8 months to mars (one way) even our fastest craft take years to reach the outer planets. If space fairing nations where able to agree on common mission and pool resources technology and since we may be able to advance more quickly still the closest star system is 25,277,549,200,000 miles away which it would take the fastest man made object 19224.34 years to reach it.