How I Landed on Mars

Caltech geology graduate student Katie Stack says her Caltech experience has provided her with the best of both worlds. Literally.

As one of five Caltech graduate students currently staffing the Mars Science Laboratory mission, Stack is simultaneously exploring the geologic pasts of both Mars and Earth. She and her student colleagues apply their knowledge of Earth's history and environment—gleaned from Caltech classes and field sites across the globe—to the analysis of Curiosity's discoveries as well as the hunt for evidence of past life on the Red Planet.

"Mars exploration is that perfect combination of understanding what is close to home and far afield," says Stack, who studies sedimentology and stratigraphy in the lab of John Grotzinger, the mission's project scientist and Caltech's Fletcher Jones Professor of Geology.

"The mission is providing a different perspective for seeing the world . . . as well as for seeing myself," she adds. "As a graduate student, you often struggle with your place in your academic community, and taking part in the mission is one of the ways that we are just thrown into the mix. We are working on the same level as a bunch of senior scientists, who have a lot of experience, and yet they are asking us questions—seeking our expertise. That's an experience you don't often get to have."

Caltech's graduate student participants on the MSL—who include Stack, Kirsten Siebach, Lauren Edgar, Jeff Marlow, and Hayden Miller, all from the Division of Geological and Planetary Sciences—represent the largest contingent of students from any one institution in a mission that has more than 400 participating scientists. Caltech's strong student presence is aided in large part by the leadership role that faculty are playing in the mission as well as the Institute's close proximity to mission control at the Jet Propulsion Laboratory (JPL), which Caltech manages for NASA.

Caltech's graduate students are among the mission personnel responsible for sequencing the scientific plan and programming the rover each day, as well as for documenting the scientific discussion and decisions at each step of the mission. As the mission's blogger, Marlow also helps share the science team's work with the public.

"The graduate students are the heart of the mission," Grotzinger says. "They are the keepers of the plan and are able to efficiently operate the technology to run the rover every day, especially when senior scientists are unable to do so."

Making the science plans for the rover, says graduate student Kirsten Siebach, is "as close as I get to driving the rover. I can help program it to take pictures, analyze samples, and shoot the ChemCam laser."

"It's always fun when something that I helped command the rover to do, like take a picture, ends up making the news," she adds. "I helped command it to take one such picture of the Hottah outcrop that showed evidence of an ancient streambed."

In addition to staffing operations for the mission, Caltech's students are also key contributors to the scientific analysis of the data and help make decisions about where Curiosity goes.

Before Curiosity landed, for instance, Stack and Lauren Edgar, helped compile a geologic map of the Gale Crater landing ellipse, using orbital images to identify the geologic diversity and relationships among rocks. Their work has continued to serve as a "road map" for the rover's research. Meanwhile, Siebach has been exploring the history of water on Mars, looking at the geomorphology of channel structures and fractures on the planet.

"We really have grown up in the golden age of Mars exploration," Edgar says, noting that while at Caltech, she's had the opportunity to contribute to three Mars rover missions—Spirit, Opportunity, and now Curiosity. "They just keep getting better and better."

In addition to the graduate students, several undergraduate students have taken part in the mission, participating through Caltech's Summer Undergraduate Research Fellowships (SURF) program. This past summer, a student working with Bethany Ehlmann, an assistant professor of planetary science at Caltech and an MSL science team member, helped to characterize and classify hundreds of Earth rock samples for potential comparison with Mars specimens that will be analyzed by the ChemCam instrument. Meanwhile, over the past two summers, Solomon Chang, a Caltech sophomore studying computer science, worked with JPL engineers to model Curiosity's mobility to ensure that it would actually move on Mars as it had been programmed to do.

Those summer projects have ended, but for the Caltech grad students on the MSL team, the work continues. Indeed, says Grotzinger, because many of the mission's scientists will be leaving Pasadena to return to their home institutions during the coming months, the grad students will be called upon to fill additional roles in the rover's daily operation and science.

"One of the great things about working on a mission as a student is that science is a fairly merit-driven process," says Ehlmann, who participated in Mars exploration missions as both an undergraduate and graduate student. "So if you have a good idea and you are there, you can contribute to deciding what measurements to make, can develop hypothesis about what's going on. It's a very inspiring and empowering experience."