stephen indyk - usra-houston · seismic probe 19 . seismic • seismic sensor to be placed 0.5 m...

Technologies for Lunar Exploration

Stephen Indyk Systems Engineer

Kris Zacny VP

LEAG 11 October 2017

Background

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• Over the past two decades, we developed numerous robotic

systems for lunar exploration

• These could be used on small and large landers, rovers, and

by astronauts

• Science:

– Heat Flow Probe

– Seismic

– Corner Cube Reflector

• Exploration

– ISRU

– Pneumatic Sampling

– Coring and drilling

– Scoops

– Geotechnical systems

– Rovers

Regolith Sample Acquisition and Delivery

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PlanetVac

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Project with The

Planetary Society

Vacuum Chamber Results

• Average sample mass captured: 20 grams

• Average gas mass at 160 kPa: 0.02 gram

• 1 gram of gas at ~160 kPa could loft over 1000 grams of soil

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Heat Flow Probe

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Heat Flow Probe

Nagihara et al., LSC, 2008

The big issues:

• thermal isolation between

thermocouples themselves

• and from a surface lander/system

Thermal conductivity k:

• heat regolith,

• measure T change

Flow = - k *

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• 2 Heat Flow probes 10 m apart: 2 independent measurement and lateral variation

• A15: drill got ‘stuck’ and never managed to drill deep enough (2.4 m)

• A16: astronaut tripped over the wires – experiment got damaged

• A17: success but it was a tough work!

Apollo Experience

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How to penetrate lunar regolith?

• Two options:

1. Remove regolith and make space for the probe

2. Crush regolith and push it into the borehole (pile driver)

• Examples

1. Drill a hole, insert a heat probe into it

2. Drill a hollow, low conductivity casing, insert a probe

(Apollo)

3. Drill a probe into the regolith

4. Pound the regolith into the regolith

1. Top hammer system

2. Mole

5. Pneumatic

http://www.astronautarchives.com/Apollo.htm

Not collapsed

Pneumatics: Proof of Concept

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• Excavation accomplished by injecting gas

• Use dedicated gas tank or He from propulsion

system

• Large gas efficiencies possible if deployed in

vacuum

Components and Deployment

• Compressed gas flows down the tube within the

stem and perforated cone and impacts regolith

underneath the cone

• Gas lifts regolith out of the hole

TRL 5 (1.2 kg)

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Proof of Concept to 3m: Pneumatic Spear/Drill

• Tests at 760 torr with 20 N Force in compacted (1.9 g/cc) NU-LHT-2M

• Gas Flow 2-2.5 ft^3/min. Approx. 67-83 grams of air at 120 PSI

• Reached 3 m in 1 min

3.5 m

NU-LHT-2M

Vibratory

compacted

Vibrator

Gas flows

down

Hollow

Rod

Testing deployment

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Test in NU-LHT-2M

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Vibratory

compacted

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Pneumatic drilling to 2 m

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Tests in NU-LHT-2M

• Reached 2 m in 2 min

• Stop and Go successful

(required for getting k

at various depths)

~2 m

Seismic Probe

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Seismic

• Seismic sensor to be placed 0.5 m – 1 m below the

surface to improve sensitivity (i.e. less noise from thermal

waves, better coupling to ground)

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PI: Matt Siegler

PSI

Seismic Testing

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• Pneumatically drilled with a 5 cm

diameter probe

• NU-LHT-2M compacted to 1.9 g/cc

• Tests in vacuum chamber

Seismic Testing

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• 1 m in 25 seconds

Acknowledgements

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• SBIR

• PIDDP

• PICASSO

• The Planetary Society

Thank you!

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