Later this month, the recently concocted NASA Mars Program Planning Group will present options for "low-cost" Mars missions that could be launched over the next five years. Do not believe for a moment that scientists do not know what they want to do next in exploring Mars, or that anyone needed a new "planning group" to come up with ideas.
The next step in Mars exploration was laid out last spring, through the National Academy of Sciences' Planetary Decadal Survey, led by Dr. Steve Squyres, science lead for the Spirit and Opportunity rovers. While more orbital infrastructure around Mars is needed, the study participants restated the consensus that has existed for decades in the scientific community—that the next big step in exploring Mars is to return samples to laboratories on Earth. Any proposed missions that do not contribute to that end, should not be done, they conclude. Only by applying the tools that can only be deployed in our best scientific laboratories can answers be found to profound questions, such as the possibility of life, past or present, on Mars.
But the Obama Administration cancelled U.S. participation in the joint project with Europe, to land, rove, and collect samples on Mars. The soil and rock samples would be cached on the spacecraft, waiting for a future vehicle to retrieve them and return them to Earth. In the proposed FY13 budget, not only participation in Europe's ExoMars was ended—Mars exploration funding was emasculated, being cut by 40%. To placate furious Mars scientists and an almost equally furious Congress, the White House set up a planning group, just days after the budget was released, to try to find "cheaper" missions to Mars. There can be no more "flagship" missions, in the $1+ billion range, in this "cheaper" world. A Mars sample return mission is off the table. As Steve Squyres said in reaction to this approach, you cannot answer big questions with small missions.
But now, the situation has changed. Does the American public believe that counting pennies should determine what discoveries we make in science? Curiosity has not even started its scientific mission yet, but it has rekindled a spark of optimism about the future.