"A robotic mission to collect soil and rock samples and return them to Earth for analysis would likely cost between $6 billion and $8 billion and not be feasible until the 2020s."

Gosh, do they mean that NASA lied, or were they simply incompetent way back LAST decade when Goldin et. al. talked about MSR circa 2003/4? Now it's 2 more decades before it's even feasible???

Guess rocketry and robotics is on a negative development curve. Remember, 3 decades ago in 1976 using electronics developed in the 1960s, two spacecraft landed safely on Mars. But hey, that program was run by the same folks and the same mindset that got us from sub-orbital to the moon in just a few years, not by the Powerpoint engineering culture.