A manned mission to Mars has been a longstanding goal of space programs worldwide: the Russian, Chinese, and American space programs all ostensibly have plans to land humans on the Red Planet. It's a bipartisan proposal: Presidents George H. Bush, George W. Bush, and Obama have all explicitly mentioned Americans hopping around the martian surface as a goal of U.S. space policy.
Grand plans have come and gone, stagnating due to flagging political will and seemingly prohibitive price tags. But just how difficult is it to fund a manned mission to Mars? Is the multibillion-dollar price tag really a deal breaker?