Lunar Drilling and Driving Carnegie Mellon December 2007 Red Whittaker

Carnegie Mellon | 13 December Mission Scenario Land on crater floor Operate in perpetual darkness Multiple drill-drive cycles

Carnegie Mellon | 13 December 20074

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7 Coring 1 meter drilling –ø30 cm borehole –ø1.5 cm continuous core –~50 kg –0.5 m x 0.5 m x 1.5 m volume Operations: –Drill to depth –Capture core, transfer –Chop core segments –Crush –Load oven

Carnegie Mellon | 13 December Coring, Crushing, Baking, Analysis Coring Sample transfer MeteringCrushingBaking Extraction Sensing

Carnegie Mellon | 13 December 20079

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Carnegie Mellon | 13 December

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December Polar Scenario Land in crater –Direct to floor, no crater wall descent –Minimal lander Communicate by polar orbiter relay Power from isotope source, no solar Navigate in darkness –Active sensing using laser light-striping Operate with supervised autonomy Survey multiple locations –Characterize regolith composition and physical properties –Determine nature and abundance of hydrogen Survive 7 months –25 drill sites x (5 days/site, 3 days/traverse) = 200 days Mass kg

Carnegie Mellon | 13 December Issues for Robotic Drilling Drill dominated Robot Design –Stiffness & Reaction to drill –Crouching to lower drill before boring Mobility over rough terrain –Suspension and flotation for lunar terrain –Sensing and operation in darkness Power –Radioisotopic power scenario

Carnegie Mellon | 13 December Mass and Scaling of Robot Robot weight on lunar surface enables drilling Applied thrust Resisted torque

Carnegie Mellon | 13 December Scarab Rover

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December System attributes Drill implementation –Central location on vehicle to maximize weight for downforce –Direct mounting to chassis –Fixed drill structure Reduced actuation Functions as navigation mast Simplifies kinematics & mass properties Adjustable kinematic suspension –Body roll averaging over terrain –Bring drill to surface to operate –High stiffness platform to react drilling forces Skid steering –Reduced actuation –Increased stiffness Thermal approach –Utilize heat from radioisotope power supply –Shunt excess heat to radiator surface

Carnegie Mellon | 13 December Straddling

Carnegie Mellon | 13 December Drilling

Carnegie Mellon | 13 December Pose adjustment mechanism Raises & lowers by actuating wing angle (independent L & R) Center link bisects wing angle: enables lift-and-level body averaging Retains advantages of passive rocker bogie

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December Leveling

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December Differencing

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December Objectives Develop Drill-dominated Mobility –Accommodate drill and sample processing payload –Stabilize mechanism during drilling –Access sites of interest Address Lunar Polar Considerations –Operation in darkness No solar power Constant low-temperature (80K) Active perception –Mission relevant concept Multiple drill-drive cycles over kilometer scale Rover scale and mass

Carnegie Mellon | 13 December Vehicle requirements Drill dominated design –Bring drill to surface to operate –High stiffness platform to react forces Mobility over rough terrain –30 cm obstacles –Steep soil slopes Environments –Fine, abrasive dust –Vacuum, 40 K ground, 3 K sky Power –Radioisotopic power supply

Carnegie Mellon | 13 December Integrated Driving and Drilling Drill implementation –Central location on vehicle to maximize weight for downforce –Direct mounting to chassis –Fixed drill structure Reduced actuation Functions as navigation mast Simplifies kinematics & mass properties Adjustable kinematic suspension –Body roll averaging over terrain –Bring drill to surface to operate –High stiffness platform to react drilling forces Skid steering –Reduced actuation –Increased stiffness Thermal approach –Utilize heat from radioisotope power supply –Shunt excess heat to radiator surface

Carnegie Mellon | 13 December Specifications Mass: 280 kg Weight:460 N  2750 N  Power (driving): 200 W (peak)  Power (posing):380 W (peak)  Power (idle): 78 W Speed: 5.0 cm/s (6.0 cm/s max) Height (with drill tower): 2.2 m high stance, 1.6 m low stance Width (wheelbase):1.4 m Length (wheelbase): m Aspect (track/wheelbase):1:1 low stance, 1:2 nominal, 1:7 high Wheel diameter:60 cm

Carnegie Mellon | 13 December Specifications CG height: 0.64m nominal, 0.60m low, 0.72m high Static pitchover: 42° nominal stance, 29° high, 45° low Static rollover: 53° nominal stance, 48° high, 55° low Maximum / minimum straddle:57 cm, Belly contact Approach / departure angle:105° nominal stance Breakover angle:115° nominal stance Rim pull (single wheel): 2500 N Drawbar pull:1560 N (medium-coarse grain sand)

Carnegie Mellon | 13 December Driving in the dark Localization –Rim camera Terrain Mapping and Obstacle Detection –Light striping (front/rear) –Both horizontal and vertical stripes for terrain mapping while driving straight and turning Imaging –Flash stereo / Flash ladar –Mounted on a pan/tilt for 360º coverage Dead reckoning / mapping support –IMU –Wheel encoders Workspace imager –Underbelly mounted camera with LED illumination

Carnegie Mellon | 13 December

Carnegie Mellon | 13 December Future Evolutions Internal actuation; eliminate external wiring;Shaft-drive Actuated suspension to surmount extreme obstacle or extricate from twist Space-relevant wheels & tread: design, fab, mount Hosting more of RESOLVE subsystems Adding Nav sensors and position estimation from rim Increase dimensions of chassis and body-averaging beam Thermal isolation of cold drill and warm body Use Scarab to load RESOLVE experiments ‘Inchworm’ locomotion