</p> <p>The basis for this report was President Bush's proclamation that the u.S. should land astronauts on Mars by 2019 A.D. In such a trip, astronauts would be in a weightless environment for a considerable length of time. This report examines different conditions and environments that could cause stress during such a long duration space mission. Both psychological and physiological conditions are examined and the human factors implications of those potential problems are discussed. Finally, recommendations are made as to potential countermeasures and/or standards that should be followed.</p> / Master of Science