But the very last space ship to Io is leaving imminently. Sam, realizing she doesn't have enough oxygen to get to the launch site, is resigned to stay in her little tranquil corner of a changed Earth. Remember, Sam's been led to believe this is the most noble path. As her father intoned on TV's last-ever news broadcast, "Planet Earth is a miracle in the universe. We are its caretakers. It is our duty to stay and fight for our world. Humans may have nearly destroyed our home, but we can make it habitable again. We will breath the air again. The strong, brave souls that will stay will become a civilization of its own design."