Space jail station.

Space is the place where there are no-escape zones like on other planets in solar system (Mars, Mercury)  from where are no escape abilities due to gravity force acting on every body in surrounding world. Well, if you want to jump up in the planetary gravity you must count with the fact that sooner or later you will fall down on the surface of a planet again, so as you know without a proper technical means to escape from the gravity you will be always a looser with this force. Also in the case of space station, this could be the kind of isolation for malicious and bad people with or without gravity - if we talk about stations without artificial gravity system or not, where the escape from is futile for one important reason, there is no life sustain outside the station, so if you want to avoid boiling up yourself in low pressure in vacuum condition existing outside you must stay at “home”. So these cases are ideal examples of hypothetical jail of couse in our days they are only hypothetical because the civilization is not yet propagated outside of our planet maybe with exception of such a small space station like ISS or MIR.  No man has walked on other planet since Apollo mission program. No planet was conquered with exception of our Moon, which is of course not a planet, saying exactly.