chriscdc said, "<font color="yellow">I strongly suggest that you look up the meaning of hibernation. The very fact that the metabolism slows down, means that damage caused during the day can not be repaired. Sleep is more complex than just saving energy. For example when you use your muscles, you cause microscopic rips in the tissue. During sleep the muscles repair themselves. Repairing the tissue requires alot of energy. With the lower metabolism you do not have that energy and so cannot repair themselves. Even in zero G you will feel like hell after a few days. Hibernation could be used for the trips to and from mars, but that is not what you indicated in your original post. The thread is also about how to extract a breathable atmosphere from the martian environment. Also I would suggest that you do not take wikipedia as your source material for any official use. Useful as it is, it is inherently not reliable.</font><br /><br />Jatslo said, "<font face="verdana" color="#99FFFF" size="3">The amount of sleep and hibernation needed depends on both the individual and the environment. For instance, Mars is far, far away and absent of nourishing fuel that a crew of seven will require, and the time spent getting their is chalk full of all kinds of biohazards. Effective hibernation will offer protection from cold when normal body temperature cannot be maintained and food is scarce. Growth and repair of cellular non-essentials in terms of biology during hibernation, and all body activities are reduced to a minimum: there may be as few as one or two heartbeats a minute. This by no way means that the body cannot repair itself similarily the way sleep does.</font>"<br /><br /><b>SLEEP:</b><br /><br />The encyclopedia said, "<font face="verdana" color="#99FF00" size="3">Resting state in which an individual becomes relatively quiescent and relatively unaware of the environment. During sleep, which is in part a period of rest and relaxation, most physiological funct</font>