Dr. Z's Zombie Apocalypse

Doctor Abraham Henry Zolnikov has spent the last seven years isolated in his orbital laboratory, watching the Earth below descend into chaos. A biological virus and a nanite programming virus have combined to create flesh eating, mindless abominations that hunt all other living things for food. Human civilization fell in a matter of weeks. There has been no indication of any living survivors on Earth's surface for over two years. As far as he knows, he is the last living human in the entire solar system. Then one day the power begins to fail on the space station he’s called home for over a decade. Stepping outside the lab will be risky. But remaining means certain death. The good doctor is a curious man, however. If he manages to survive, who knows what hidden secrets he will discover?