Atacama I: Science Results of the 1997 Nomad Rover Field Test in the Atacama Desert, Chile. Cabrol, N. A., Chong-Diaz, G., Dohm, J. M., Arredondo, M., Dunfield, G., Gulick, V. C., Jensen-Iglesia, A., Keaten, R., Lamelli, C., Landheim, R., Lee, P., Pederson, L., Roush, T., Schwehr, K., Stoker, C. R., & Zent, A. In Lunar and Planetary Institute Conference Abstracts, volume 29, pages 1013, 1998.
Atacama I: Science Results of the 1997 Nomad Rover Field Test in the Atacama Desert, Chile [pdf]Paper  abstract   bibtex   
The Nomad rover was deployed for 45 days in the Atacama Desert, Chile, during the summer of 1997. During this period, the rover set the record of the longest traverse ever performed by an automated vehicle (220 km), while controlled by operators either at NASA Ames and Carnegie Mellon. During this traverse, between June 20th and 27th, the rover was used to perform science experiments. Both Science and Operation Team controlling the rover were located at NASA Ames, while a Field Science Team was in the Chilean Desert to ground-truth the operations. The Atacama Desert: The Atacama desert includes a variety of features and characteristics that make this site a unique place to perform experiments on planetary-analog surfaces (i.e., Mars and the Moon): craters from meteoritic impacts, volcanoes, rocks and sand fields, total lack of vegetation due to the absence of rain (1 cm/year from fog), ancient - and now dry - lake beds and sea floor. The average elevation of the test area (23Ą20ŐN/68Ą37ŐW) was 2400 m, and the diurnal temperature variation from 0Ą to 25ĄC. The terrain offered challenges to test the vehicle mobility and trafficability capacities, with a succession of soft surfaces due to the accumulation of smooth materials, and ravines left by ancient channels currently dry which eroded the desert in the past. Overall Project and Science Objectives: The field test was designed to demonstrate and validate: (a) robust locomotion, navigation, visualization, and communication in a long-distance, long-duration traverse in ChileŐs Atacama desert, (b) perform end-to-end trial under remote control; teleoperation and autonomous control with simulated time delays. The objectives pertaining to the NASA Ames science field experiment were to: (1) provide realistic desert experience for remote operators through highquality imagery, (2) simulate NASA missions (Mars, Moon, and Antarctica) by: (a) training scientists, (b) evaluating control environment appropriateness, (c) developing and evaluating exploration strategies, (d) evaluating best interaction by distributed science teams, (3) evaluate the importance of various image techniques, i.e., panospheric imaging, pan/tilt camera, stereo imaging, close-up imagery, (4) understand the reasons of data misinterpretation in previous field experiments by ground-truthing with feedback to the Science Team at NASA Ames, and careful evaluation of scientistsŐ procedures and protocols. Nomad Rover: Capabilities and Science Package: Nomad is a four-wheel drive, four-wheel steer robust rover (wheel diameter: 76.2 cm), of 2.4 x 2.4 x 2.4 m deployed, and 550 kg mass, with a transformable chassis. The rover used an actively pointed antenna to support high-bandwidth telemetry [1], [2]. NomadŐs average speed was 0.3 m/sec, though it was able to sustain 0.5 m/sec during the simulated Mars and Moon operations in open terrain. Navigation was enabled by Inertia Measurement Unit, Gyrocompass, and Global Positioning System (GPS), with a precision of about one meter. The imagery system included a panoramic camera with an ultrawide field of view (360Ą x 40Ą above horizontal) using a spherical mirror mounted above the vertically oriented digital camera [3]. The science imaging system (high resolution cameras) was designed to reach the resolution of the human eye (see specifications below): Ľ Color Stereo Cameras: 640x480 pxl; 0.29865 mrad/pxl; 8 x 11Ą FoV; 8 bit per color (24 total); left/right stereo separation: 25 cm; Ľ Black and White Stereo Cameras: 640x480 pxl; 0.895 mrad/pxl; 25 x 33Ą full FoV; left/right stereo separation: 12.5 cm; Ľ Panospheric Camera: 1024 x 1024 pxl; 360Ą FoV; 1 Mbyte per image; Ľ Science Instrument: Magnetometer: sled dragged behind Nomad on rigid towbar; sensor footprint: 8Ó at 13 cm. Ľ Aerial Photos: 1 m/pxl resolution Ľ Weather Sensors: Temperature; humidity, wind velocity. Exploration Strategies: The goal was to prepare near-term planetary missions by testing different exploration strategies. The planetary mission scenarios included: (1) Mars Caching Samples by a thorough examination of the sites, with and without panospheric

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