Why Is It So Hard to Go to Mars?

Why Is It So Hard to Go to Mars? | Russia & Phobos-Grunt Mission, Mars Exploration | NASA & Mars Science Laboratory, Curiosity Rover | Space.com: "As NASA prepares to launch its huge new Curiosity rover toward Mars on Saturday (Nov. 26), the current travails of a robotic Russian probe stranded around Earth offer an uncomfortable truth: Getting to the Red Planet is tough"