They would still have to live through the 6+ months of hard space before making it to Mars. So you'd also have to include a heater and a window, at a minimum. A

They would still have to live through the 6+ months of hard space before making it to Mars. So you'd also have to include a heater and a window, at a minimum. Also, it would need to be a biosphere, to generate carbon dioxide until it reached Mars.