Every challenge astronauts will face on a flight to Mars

In 1972, the space race officially ended as NASA sent one last crew of astronauts to the surface of the moon (Apollo 17). This was the brass ring that both the US and the Soviets were reaching for, the "moonshot" that would determine who had supremacy in space. In the current age of renewed space exploration, the next great leap will clearly involve sending astronauts to Mars.