John Grotzinger is leading a march up a mountain near Death Valley, the rocks around him streaked red, brown and purple-gray.
The geologist has often brought staff members up here, away from the blinking control rooms and glaring light of test beds at the Jet Propulsion Laboratory about 250 miles to the southwest.
Engineers who normally fiddle with electronics will smash rocks with geologists' hammers. Planetary scientists will practice tracking layers of rock to piece together the story of the land.
It's a break from the lab grind, but that's not the point. As project scientist for the Mars Science Laboratory, the NASA rover scheduled to land on the Red Planet on Sunday night, Grotzinger guides hundreds of researchers who work with rover instruments that will capture video of the terrain, scoop up soil or shoot lasers at rocks, in search of the ingredients for life.
Once the rover — nicknamed Curiosity — touches down, the crew will see the landscape through the machine's eyes only. These trips into the forbidding desert help them to develop a gut sense of the Martian terrain and to start thinking a bit like a Mars rover themselves.
"Until you're actually staring at a rock outcrop and walking around it, you don't have the intuition of what this rover's going to do on Mars," said Ashwin Vasavada, one of Grotzinger's two deputies, recalling a 2008 field trip.
"He would ask us, 'If you were the rover, where would you drive? Where would you point your camera? How would we, as a team, explore this particular site, if this was what was in front of us on Mars?' "