Life Support
  Air, Water, and Nutrition
  Waste Management
  Mental Health
  Suits
  Radiation and Zero-G

Habitat On Mars
  Power
  Structure
  Daily Routine

Structure Overview

The structure of the habitat depends on many things and is influeced by just about every aspect of the mission. It must be strong enough to withstand wind and other surface weather patterns found in the Martian atmosphere and at the same time be light enought to make the decent to ths surface safely. It must also be large enough, or give the appearence that it is large enough to keep the mental health of the atronauts in good condition, and at the same time be able to survive a journey through space and more importantly the decent through the Martian atmosphere.

Specifics

The Habitat floor plan will have the general shape of an octagon for several reason. The two most influencing reasons being that an octagon can be cross braced and reinforced in mutliple ways and the second is that its shape will make the habitat appear larger. The circular pattern will create the idea that there is more area in the living quarters and thus reduce stress on the astronauts. This floor plan will also allow for sleeping and living quarters to be easily divided. The shape its self is very solid once constructed because it does not easily allow twisting and very evenly ditributes loads throughout the entire structure. The octagonal shape also will allow for less resistance of wind as there will be less of a flat wall to hit and instead a relatively curved object for air to smoothly flow around. At current it is believed that a habitat skeleto which have a protective skin will be what the habitat will be composed of. Ontop of previous layers will be shielding layers for radiation and heat.

Unkowns

Selected References:
http://spaceflight.nasa.gov/history
http://artic.marssociety.org
Zubrin, Robert "The Case for Mars" Touchstone, 1996