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Asteroid ISRU

Kris Zacny Honeybee Robotics, Pasadena, CA

SBAG, Tucson , AZ

13 Jan 2017

Resources: Recap

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Asteroid

Free Water Hydrated Water Regolith Metals

Metals: REE and PGM

• Economic value is uncertain:

– Schedule/ cost for metallurgical processes?

• If returned to earth:

– Price change given high supply?

– New markets (increased demand) as a result

of price drop?

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Aluminum

Example: Aluminum

• Bayer process (bauxite is purified).

– aluminum ore is mixed with the sodium

hydroxide oxides of aluminum and silicon

dissolve

– Carbon dioxide gas is bubbled through weak

carbonic acid forms causing the aluminum

oxide to precipitate. After filtration, and boiling

to remove water, purified aluminum oxide can

be obtained.

• The Hall Heroult Process (aluminum removed

from oxide)

– aluminum oxide is mixed with cryolite and

heated to about 980 °C to melt the solids.

– molten mixture is electrolyzed aluminum

ions are reduced to form aluminum metal (at

the cathode)

4 http://sam.davyson.com/as/physics/aluminium/siteus/extraction.html

Regolith – Not a Bad Resource

• 3 D printing and sintering

– Fuel tanks, spacecrafts structures, habitats,

radiation shielding

– Not necessarily as strong as on earth

• Zero gravity

• No launch loads

• Radiation shielding

• Soil for agriculture

5 NASA

ContourCrafting

Water: Low Hanging Fruit

• Propellant

– LOX and LH2

– Oxidizer: LOX

– Solar thermal engines

– Could be large market

• Sustain human presence in space

– e.g. drinking water, O2

– over 90% of water is recycled on ISS

• Radiation shield

– Market is limited and finite

• Agriculture

• Market is subject to recycling of the water

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O2 H2

3 Step Approach For Mining Water

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• Reconnaissance

– From a safe distance

– Density, porosity, ‘strength’

– Includes Kinetic Impactors

– Guides sampling approach

• Prospecting

– Need a sample

– Ground truths resources, contaminants

– Allows selection of the optimum mining approach

• Mining

– Recovery and processing of water

– Delivery to a customer

NASA

3 Step Approach For Mining Water

8

• Reconnaissance

– From a safe distance

– Density, porosity, ‘strength’

– Includes Kinetic Impactors

– Guides sampling approach

• Prospecting

– Need a sample

– Ground truths resources, contaminants

– Allows selection of the optimum mining approach

• Mining

– Recovery and processing of water

– Delivery to a customer

NASA

3. Mining

< ~20 m size > ~20 m size

Capture, extract resource in situ,

return final product

Extract In-Situ and

deliver final product

Mine feedstock and

deliver for processing

Reconnaissance

Spider RAP

2. Prospecting 1. Recon

Exploration Hierarchy

1st Step Reconnaissance:

Kinetic Impactor

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Overview

Titanium Ceramic “Paintball”

• Crater sizes = regolith strength

• Rebound vel. = rock strength

• Ceramic shell, breaks at

set rock strength

• Retro reflectors spill out

~100 shots ~10 shots

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See

https://www.youtube.com/watch?v=Hr4kUFB8LCg

2nd Step: Prospecting

Capture Sample

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PlanetVac

Soil Sampling Tube

- in each leg for redundancy

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See

https://www.youtube.com/watch?v=JzMn5DbhpjE

Step 3: Mine Water-Ice

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3. Mining

< ~20 m size > ~20 m size

Capture, extract resource in situ,

return final product

Extract In-Situ and

deliver final product

Mine feedstock and

deliver for processing

Reconnaissance

Spider RAP

Water Extraction

Spider Miner For Large Asteroids

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Reactor and

Anchor

Captures, Processes and Recovers in Situ

Volatile Extraction Options

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Sniffer MISWE Corer Porcupine

Perforated cone is heated,

volatiles flow through holes up

the hollow center to the cold

trap.

Deep fluted auger captures

sample and retracts into tube.

The tube/auger is preload

against the ground. Auger is

heated and volatiles flow

through the holes, up the

annular space and into a cold

trap.

Double wall corer with

outer insulating auger and

inner perforated and

conductive tube. Material

within inner tube is heated,

volatiles flow through

holes and up the annular

space into a cold trap.

Cartridge heaters

penetrate the surface to

heat volatiles that flow

through a perforated sheet

into the greenhouse dome,

which funnels them into a

cold trap.

Eff Low High V. High Low

Comp

lexity Low Medium Low Low

Risks Auger freezes

Holes clog with material

Material does not fall off the

flutes

Cannot empty the corer

Holes clog with material

Poor surface contact

allows volatiles to escape

Heating elements freeze

Corer: C1 Asteroid Simulant (Metzger et al., 2016)

• 2 inch diameter version

• 50 W, 1 hour

• Results: 2.9 g, 1.5 wt%

• Recap: JSC-1A with 12 wt% water

– Best case: 67% extracted, 8wt% collected

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Power (W) Time (Hr) Vacuum/Ambient Extracted (g) Simulant (g)

50 1 Ambient 5.1 203

50 1 Vacuum 3.8 183

50 1 Vacuum 2.2 198

50 1 Vacuum 1.8 206

2 inches 5.3

5 i

nch

es

Pressure cooker (Metzger et al., 2016)

• “Pressure cooked” volatiles

• Up to 4.4 g/hour

– 2 hour cook time

• Over 400 °C external

– Thermal camera where

thermocouples fail

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For Small Asteroids

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Bags, Heats up, Captures Volatiles

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Acknowledgements

• NASA SBIR Program

• NASA BAA ARM

• NASA NIAC

• The Planetary Society

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References

Zacny et al.,

“Drilling and excavation for construction and in situ resource

utilization,” in Asteroids: Prospective Energy and Material

Resources, by V. Badescu

Kris Zacny , Phil Chu , and Jack Craft, Marc M. Cohen, Warren

W. James, Brent Hilscher, Asteroid Mining, AIAA

Space2013, San Diego, CA, 10-12 Sept, 2013

Zacny, K., B. Yaggi, P. Chu, J. Johnson, A. Kulchitsky, M.

Hedlund, K. Davis, B. Hermalyn, P. Less, G. Paulsen, and J.

Abrashkin, DB., et al., (2015), Thumper and Shotgun: Low

Velocity Kinetic Penetrometers to Estimate Regolith and

Rock Properties for NASA’s Asteroid Redirect Mission

(ARM), IEEE Aerospace conference, 9-13 March 2015, Big

Sky, MT.

Zacny, K., B. Betts, M. Hedlund, P. Long, M. Gramlich, K. Tura,

P. Chu, A. Jacob, A. Garcia, (2014), PlanetVac: Pneumatic

Regolith Sampling System, IEEE Aerospace Conference, 3-7

March 2014, Big Sky MT

Philip T. Metzger, Kris Zacny, Kathryn Luczek, Magnus Hedlund,

Analysis of Thermal/Water Propulsion for CubeSats that

Refuel in Space, ASCE Earth and Space Conference, April

11-15, 2016, Orlando, FL