Earth to Mars trajectories for radiation study

Animation of the three round-trip trajectories between Earth and Mars. T1 stands for the minimum energy trajectory with a 450-day stay on the surface of Mars; T2 is a fast transfer trajectory that constrains the surface stay time on Mars to about 30 days; T3 stands for an even faster transfer trajectory based on T2, limiting the total mission duration to 440 days. The transfer trajectories are represented by grey dashed lines, and the asterisks indicate the midcourse impulse.