Space Travel Future

From Einstein's special theory of relativity we learn that time is not uniform. For different observers in space time passes differently depending upon their relative speeds. 

The following is the expression for time dilation:

Where T= change in time of a body moving with velocity v 

           Tr = change in time of a body at rest 

             c= velocity of light in vacuum

Now for small values of v the time passing in both the mediums is same, that's why here on earth we find that there is hardly any difference between the time passing for a man standing in a bus stop as compared to a man travelling in a car. 

But if we build a spacecraft which has some kind of fuel that can constantly accelerate it and gain speeds upto 99.9999% , in that case 1 day (24 hours) in the spaceship would be equivalent to 707 days on earth. Such space ships can reach distant stars and for the astronauts on board very little time would passed in the entire travel . But when they come back to earth thousands of years would have passed. 

      NASA's Kepler mission is observing 150000 stars with earth like planets in their orbit. Maybe in the future a 100 ,200 years from now we would send batches of humans to those planets , to start a human colony over there. A few hundred years from now when we have the technology . Human civilizations main target would be to travel explore and spread around the universe.