Challenges of a Manned Mission to Mars - Part 2: Human Factors

Once in microgravity, dramatic bone and blood volume loss, potential nausea, and extreme congestion are just the prelude to your experience. Thankfully, both anecdotal evidence and analysis of our accumulated time in manned space flight suggests that our bodies have a incredible capacity to adapt to those conditions, though we pay for those adaptations on our return to gravity. As concerns the long duration crew health and interaction facet, consider that the longest space mission to this point is 437.7 days, a record set by Valeri Polyakov, a Russian cosmonaut aboard Mir. This Mars mission would be longer by 240 days and involve multiple people interacting in an enclosed environment far from home. Crises involving small groups of humans in other dangerous environments highlight the potentially catastrophic effects of the interaction between mental pressures and physical danger. This is the reason why space programs choose their personnel in a manner very similar to nuclear submarine crews. As any college student who has had trouble with a roommate can tell you, close proximity has a way of magnifying character flaws and clashes, and there won't be much in the way of privacy during the mission!

A paper on supporting human spaceflight lists 38 “stressors” in long-duration spaceflight; among the effects of these stressors are listed exhaustion, depression, neuroses, and impacts on physiological performance. While maintaining contact with mission controllers, family members, and crews will help to ameliorate these concerns, the number of interpersonal interactions and the length of the mission prevent them from being dismissed out-of-hand. Magnifying this issue is the time lag that will be associated with communications. As I write this, Mars is 20 light minutes away. Try talking or playing your favorite Web-based game with that kind of lag! And, though the space agencies have shown signs of recognizing the potential seriousness of the issue and addressing this by creating new space specialties within traditional disciplines such as psychology, human factors, and sociology, there is still far too much we don’t know about long-term exposure to the space environment.

In the long run, it may happen that the best way of getting data on poorly-known conditions related to space habitation is the same way NASA built up information on the supersonic and hypersonic flight environments - by pushing back the boundaries of the unknown, one step at a time. The only way to find out for certain is to go out there and learn as much as we can while being as cautious as we can, and right now, we've got the time (and an intermediate destination) that will allow us to do precisely that.