Never happen, we will not go back to the moon, or ever try for Mars. After Jesus comes and kicks some evil bootay yes. Man by himself, we are too busy fighting each other and always will be.
Here is the correct answer.
A United Planet is required to do this and all we have to do is look at the DN (Do Nothing), oops, I mean UN.
Humanity needs to combine it's best resources working together in order to explore the stars and finance it.
To date, even America can't put a man in space anymore and relies on the Russkies.
Sad state of affairs...