This is a bad idea on many levels. First off: cost. It would cost a fortune not only to send the prisoners to Mars, but to build the proper facilities to sustain life on Mars would cost even more.

Secondly, there is plenty of room left on Earth to send prisoners. Even in the United States, there is a lot of land still unsettled. It would cost less to build a new prison here.

Thirdly, there would no doubt be problems in the government. The bill would take months if not years to pass, and even then there would most likely be protesting, etc. It's just a bad idea in general.