How long will it be until Humans can live on another planet?

Question: How long will it be until Humans can live on another planet?
- Keywords:
  future,
  human,
  planet,
  space travel
Asked by Maddie to Lisa, Kate, Jos on 20 Nov 2014.
- Kate Dobson answered on 20 Nov 2014:
  
  I don’t know if we ever will be able to. We may get to live in space stations built on the surfaces of other planets, but the atmosphere, gravity and temperatures of the known planets mean we won’t be running around playing football without life support!
- Lisa Simmons answered on 21 Nov 2014:
  
  I don’ think we will ever manage it. Space stations are an option, but I wonder how functional they would actually be.

Question: How long will it be until Humans can live on another planet?