Human beings finally realize the dream of colonizing Mars. The first colony is built in the year 2997. The subterranean colony is self sufficient to sustain continuous human life. This colony was only made possible after the colony on moon was successful. Moon colony serves as a stop on the way to Mars. Both the colonies are the results of joint efforts of all the nations on the earth. Initially, only the scientists migrate to Mars. Once the colonies are fully established normal travel between the Earth and Mars is started.