September 4, 2004
Salar Grande, Atacama Desert, Chile

Agenda
• Test sun tracking and orientation estimation
• Replace locomotion power enable switch
• Power up environmental monitoring station
• Calibrate navigation cameras and system
• Test visible-near-infrared and thermal infrared spectrometers

Status and Progress
Imaged sun. Zoë carries a sun tracking camera, a 180° field of view camera that looks up through a very dark filter, that sees only the white spot of the sun in the sky. Knowing only approximate position, within a few tens of kilometers, and accurate vehicle posture, the heading angle can be determined from observations of the sun. We’ve been able to get the camera system working an observing the sun and are now making sure that all of the parameters are set correctly in the ephemeris (Earth-Sun position) calculations. Observing the sun accurately is sporadic in Pittsburgh but we are having no trouble in the Atacama.

Enabled locomotion power. Zoë’s locomotion power system is back online with a manual switch replacing the relay which failed. This means that we have to throw a switch to turn Zoë on, it can’t be done remotely through radio command to the power management computer. A replacement relay will arrive later this week.

Started environmental monitoring. Yesterday the mechanical structure was assembled, and today we powered up the computer. that interfaces the data logger and controls the motion of the pan-tilt mechanism. It will run continuously while batteries remain charged; the station like Zoë is solar powered.

Cooled experimental spectrometer. We have a thermal infrared spectrometer this season to test as an independent experiment, meaning not aboard Zoë. This device requires liquid nitrogen to cool its detector. The spectra it produces, in the far infrared, is complementary to the visible-to-near infrared spectrometer on Zoë. Both provide information about the mineralogy of the site under examination.

Upcoming
• Resume testing of power management and distribution system
• Continue testing of orientation estimation
• Focus, balance, and calibrate stereo panoramic imager
• Test and tune autonomous navigation system
• Navigate autonomously

Weather
Morning: Clear, calm, 15C, humidity 80%, heavy dew
Afternoon: Clear, light breeze 15-25kph, hot 30, humidity 25%
Evening: Clear, light breeze, 10-15kph, cool 10C, humidity 65%

Quote of the day
"Who took my Sharpie? Gimme back my Sharpie! I’m holding you all responsible!"