You have 3 terminal windows running in a desktop version of ubuntu, I assume?
You cannot SSH directly into a terminal window so far as I know, but you can ssh directly into a "machine" and then open up as many terminal windows as you would like in the background using screen.
You have to have openssh installed and port 22 open on the machine you want to log in with. Then you can simply dial up the ip address (with putty or another ssh client of your choice).
Type screen to enter screen. Hit CTRL+C to "create" a new window. You can make as many as you would like.