The Risks of a Manned Mission to Mars, Part IX

Many could argue that the biggest risk of a manned mission to Mars is the human factor. The lowest energy round trip to Mars is nearly three years. During this trip, the astronauts are confined in such a small spacecraft that they are unable to distance themselves from each other. This may lead to unwanted tensions between the crew members. Many studies have indicated that due to the isolated and confined nature of spaceflight, there are many evidences of serious interpersonal conflicts between the crew members in long-duration space missions.

“The failure of flight crews to cooperate and work effectively with each other or with flight controllers has been a periodic problem in both US and Russian space flight programs. Interpersonal distrust, dislike, misunderstanding, and poor communication have led to potentially dangerous situations.”

http://bioastroroadmap.nasa.gov/User/risk.jsp?showData=24