Astrobiology is the study of life in the universe. Robotic astrobiologists will one day search for life on other planets, but first we prepare robots to study life in extreme environments here on Earth.

Researchers from Carnegie Mellon and NASA are using robotic technologies to investigate the Atacama Desert of Chile. We are trying to understand how life survives in the driest desert on Earth; and in doing so, we are shaping the future of robotic astrobiology.

We have created a rover named Zoë equipped with cameras, a spectrometer, and a fluorescence imager to detect microorganisms living in the desert and to characterize their habitat.

Zoë’s stereo panoramic imager is a triplet of high-resolution cameras mounted atop a pan-tilt mechanism. The imager is used to observe geologic and biologic structures around the rover.

The fore optic of Zoë’s spectrometer also resides on the pan-tilt. It is sensitive to light in the visible- to near-infrared-range and is used to determine the mineralogy of rocks and soils.

The Fluorescence Imager is a new instrument created at Carnegie Mellon. It detects organic fluorescence in daylight by using a high-intensity flash-lamp and cooled-CCD imager. Paired excitation and emission filter wheels are used to image chlorophyll fluorescence as well as the fluorescent signatures of probes for amino acids, carbohydrates, lipids, and proteins.

Zoë can deploy its plow to uncover the desert’s shallow subsurface, where some organisms take refuge from the Atacama’s intense ultraviolet radiation.

Mapping the distribution of life in the Atacama requires observations across tens of kilometers. Zoë is therefore designed for desert mobility. Its onboard autonomy software allows scientists to explore the Atacama from a remote operations center in Pittsburgh.

Each morning, Zoë receives its daily exploration goals and priorities. Zoë’s planner uses an optimal search strategy in the space of position, time, and energy to generate a day-long schedule that maximizes science accomplishments and minimizes resource requirements. This path is executed by a navigator that uses stereo vision to produce traversability maps of the near-field. Four times a second, Zoë evaluates steering decisions and chooses a safe path to its waypoint.

Zoë has navigated autonomously over 250 kilometers with nothing but orbital terrain models. Zoë operates without a GPS or compass, devices that are unavailable on Mars. In seventy instances Zoë has navigated over one kilometer in a single command cycle.

Over three years of field work, Zoë has examined six sites yielding hundreds of panoramic and fluorescence image sets. Fluorescence imaging has revealed microorganisms in many areas. Imagery and spectroscopy have portrayed the surface geology and mineralogy of these habitats. Our science team is now building the first bio-geologic maps from data collected by Zoë.

Astrobiology rovers help us to understand how life may have developed and survived in extreme habitats here on Earth. They also help us to learn how to search for evidence of life on the surface of Mars.

The Atacama Desert is the most arid region on Earth. It may also be the most lifeless. In the interior of the desert, rain is measured in millimeters per decade and solar radiation is intense because of the high altitude and thin atmosphere. But there is life where the desert meets coastal mountains. The Life in the Atacama project mapping the distribution of microorganisms and seeking to characterize the habitats in which they survive.

Rovers are an important part of our work because they provide mobility to observe and measure with instruments at specific locations. This is how we will map the distribution of life. Our robotic field investigation will bring better understanding of the Atacama and how life survives in extreme environments.

Our three year investigation will use a rover to make long transects in the Atacama. The rover will carry high-resolution cameras, fluorescence imagers, spectrometers, as well as mechanisms for shallow subsurface access. Robotics research in addition to comprehensive integration includes robot configuration, power and mobility planning, localization and navigation, and autonomy and self- awareness. (more)