Preparation for future crewed missions to Mars will require
utilization of space analogs for research (such as for feasibility and verification of monitoring technologies or countermeasures) and for training of flight crews and ground support personnel. Although several ground-based analogs mimic various aspects of space exploration missions, the influence of Earth s ever-present surface gravity cannot be ignored. Until recently, lunar missions were expected to be a stepping-stone for Mars expeditions, but recent programmatic de-emphasis of lunar missions has encouraged consideration of piloted missions to Near-Earth Asteroids (NEAs) instead. It has been suggested that in-space simulations of Mars (and now NEA) missions be conducted on the International Space Station (ISS). Some possibilities for, and space life sciences implications of, such an effort are described. A brainstorming session involving space life sciences subject matter experts associated with the NASA Human Research Program, the Johnson Space Center Space Life Sciences Directorate, and the Ames Research Center Exploration Technology Directorate was convened on September 25, 2009, to respond to two questions: how can the ISS be used to mimic Mars missions; and how can crew increment duration be increased to 9 to 12 months from the existing 6 months. Positions and recommendations are indicated.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110008393_2011008928.pdf