Should space exploration be a mankind venture or just NASA be in charge of it all?

It should be an international venture. I like my country but I'm afraid weve got some poor ideas on how to aproach the stars. Even the international space station is a waste of valuable time. We could have designed a platform that we could experiment from and later use it as a vehicle to the planets. To go to mars means a ship so big and full of redundancy not to mention a small colony of people from all facets of science and engineering, medical and technical expertise. We could have been there in orbit, safely around mars to study the planet from above. Sent missions to the surface and returned them safely. We could have acomplished this in as little as 20 years. An oneill colony would have been a good choice and would have eliminated alot of the physical problems we face.