A Mars analog habitat is one of several historical, existing or proposed research stations designed to simulate the physical and psychological environment of a Martian exploration mission. These habitats are used to study the equipment and techniques that will be used to analyze the surface of Mars during a future crewed mission, and the simulated isolation of the volunteer inhabitants allows scientists to study the medical and psychosocial effects of long-term space missions. They are often constructed in support of extensive Mars analogs (see List of Mars analogs). However, sometimes existing natural places are also valued as Mars analogs. Crewed Mars habitats are featured in most human Mars missions; an alternative may be terraforming or telepresence.
The ISS has also been described as a predecessor to Mars expedition. In relation to a Mars habitat, it was noted that they are both essentially closed systems.[1]