Mars missions using solar electric propulsion

Successful demonstration of solar electric propulsion on the Deep Space 1 t echnology demonstration mission has paved the way for the use of this techn ology on future planetary missions. Currently there is much interest in ret rieving Mars surface samples for scientific exploration, as well as develop ing the technology to enable human missions to Mars sometime in the next fe w decades. Solar electric propulsion trajectories for Mars opportunities in the 2004-2011 time frame are examined. All of the trajectories shown were optimized with a gradient based calculus-of-variations tool. In addition, a genetic algorithm was used to search for more nonstandard trajectories. Mi ssion performance is presented as burnout mass along contours of constant E ight time. The superior specific impulse of these propulsion systems result s in a larger delivered mass at Mars than a conventional chemical mission. A very curious feature of these missions is that for longer Right times sol utions exist that permit a nearly continuous launch opportunity over an ent ire Earth-Mars synodic period.