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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
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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. 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