One of the larger questions scientists and engineers must answer is what role in-situ resource utilization will play in supplying astronauts with drinking water, oxygen and rocket propellant. Up until now, NASA has focused mostly on the propellant aspect, proposing that oxygen extracted from the Martian atmosphere could be used as a fuel oxidizer to help blast astronauts back into space. The Mars 2020 rover will carry an instrument called MOXIE to test out the extraction technique.

But because a wide variety of water resources were proposed at the workshop, the team behind NASA's Evolvable Mars Campaign—the long-term effort to send humans to Mars using a capabilities-first approach—is expanding its options.

"Up to now, the Evolvable Mars Campaign has, when it comes to in-situ resource utilization, been considering taking oxygen out of the atmosphere to use as fuel for the return, the Mars Ascent Vehicle," said Ben Bussey, the chief scientist for NASA's human exploration division. "In part, because of the workshop, the Evolvable Mars Campaign team is now looking at, if you had access to abundant supplies of water, how does that affect the architecture of how you get to Mars with people?" he said.

Surface water on Mars falls roughly into two categories: mineral and ice-based. Near Mars' equator, most of the water is locked up in hydrated minerals, and freeing it involves an energy-intensive baking process. At higher latitudes, water exists in ice sheets just below the surface, but it can be hard to quantify exactly how much ice is present, and how easily it can be accessed.

Exploration Zone proposers are now being encouraged to submit up to three image and data requests for the HiRISE and CRISM instruments aboard NASA's Mars Reconnaissance Orbiter. NASA will use the results, as well as the original proposals, to bracket the range of engineering constraints for hardware on the surface. Two sample exploration zones—one near the equator, and one in a high-latitude region—will be used to establish "day-in-the-life" scenarios for astronauts living in the region. This includes temperature variations, dust storms and other weather challenges, as well as the creation of sample routes that human-class rovers would traverse to reach areas of interest.