Rover and Instrument Capabilities

Life in the Atacama 2004Science & Technology Workshop

Michael Wagner, James Teza, Stuart HeysRobotics Institute, Carnegie Mellon University

Life in the Atacama 2004 Workshop 2 Carnegie Mellon

Introduction

The purpose of this talk is to summarize how our new rover chassis, called Zoë, can be used to explore the Atacama DesertIn particular, the following aspects of Zoë will influence your strategy:Long-distance explorationScience payload Power limitations

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Motivation

Our work is making possible a type of planetary exploration that has long been requested:"Further Martian exploration, both geological and biological, cries out for roving vehicles capable of landing in the safe but dull places and wandering hundreds or thousands of kilometers to the exciting places. Such a rover would be able to wander to its own horizon every day and produce a continuous stream of photographs of new landscapes, new phenomena and very likely major surprises on Mars.”

Carl Sagan, Broca's Brain

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Distance Per Day

MER5 cm/s max speed0.6 km in 90 sols (0.007 km/sol)

Hyperion, Atacama 200330 cm/s max speed10 km in 5 sols (2 km/sol)

Zoë, Atacama 2004 (projected)100 cm/s max speed50 km in 10 sols (5 km/sol)

Distance Per Sol

0.007

2.000

5.000

0

1

2

3

4

5

6

MER Hyperion Zoe

Roverkm

/sol

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Reachable Terrain

MERTraverse 30 deg slopeSurvive 45 deg slope25 cm obstacles

HyperionTraverse 10 deg slope (loose sand)30 cm obstacles

Zoë (projected)Traverse 20+ deg slope (loose sand)Survive 45 deg slope30 cm obstacles

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Obstacle Avoidance

Hyperion and Zoë both use stereo vision to detect obstacles several meters aheadPath planning algorithms guide the robot around obstacles to a waypoint Obstacle Detection Obstacle Avoidance

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Long-distance Exploration Strategy

The rover should be used to survey large portions of terrain“Drive” the robot with distant waypoints, not small movesThe robot will arrive safely if there is a path availableThe robot should recover on its own from steep slopes or large obstacles

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Zoë Science Payload 2004

Stereo panoramic imagersFluorescence instrumentVIS/NIR spectrometerPlowWorkspace camerasWeather / environmental sensorsPotential, auxiliary science sensorsStereo navigation camerasSun sensorWheels / power sensors

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Science Return

100 MB of data will be returned to the science team each solContents are up to the scientists but could include:Data from any instrument, with adjustable• Instrument settings (filters, positions, etc.)• Resolutions• Compression levels

Weather station data (“from lander”)Rover telemetry, including but not limited to:• Dead-reckoned position• Power levels• Slope measurements

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Size and Duration of Data Products

Accurate data product sizes are TBD – stay tuned

* Assumes lossless compression

Product Minimum Size*

Maximum Size*

Duration Parameters

SPI panorama 1 MB 60 MB 10 min Color depth, resolution, FOV, cropped areasSPI snapshot 100 kB 500 kB < 5 sec Resolution

VIS/NIR panorama 1.5 MB 10 min +

warm-up FOV

VIS/NIR reading 10 kB < 5 sec +

warm-upFluorescence

image set 500 kB 100 MB < 1 min to ~1 hr

Number of images, resolutions, excitation filter settings, emission filter settings

Workspace image 100 kB 500 kB < 5 sec Resolution

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Science Data Requests

The science team can command the rover to take science readings of terrain not seen in the start-of-day panorama

Zoë will be able to handle requests such as:1.Drive to this DEM cell2.When you get there, plow a trench 2 m long3.Next, take a 3 x 3 mosaic of fluorescence

images of the trench4.Finally, take a SPI panorama

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Rover Power

Zoë is solar powered by 2.4 m2 of panelsOnboard Li polymer batteries store solar energyZoë will be capable of monitoring its battery levels

and autonomously handling low energy levels:Recharging if necessarySwitch off power to optional components (science instruments, non-essential computers)Hibernate through the night in very low power modeSwitch on components when solar power is again available

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Night Operations

The end-of-sol rover location can be the site of “night science operations”Most useful for collection of fluorescence dataRover movements limited to a few metersDuration of night science TBD, but we hope to support about 1 hour of scienceAfter night science operations are complete:Download data from roverRover goes into hibernation mode

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Conclusions and Questions

Zoë provides the science team with the ability to remotely explore large distancesThis promotes a new exploration strategy more like a survey than an investigation of nearby rocks

Remaining issues:Create a comprehensive “menu” of rover actionsUpdate data product size and duration estimatesTest night operation capability