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Training thesis:
Feasibility study of extrac7ng
water from near-‐Earth asteroids
Nina Kallio M.Sc. student in EES University of Groningen Supervisors: Dr. C. Visser Dr. T. Schoot Uiterkamp
Mo7va7on and relevance (WHY?)
• Deple7ng resources • Water the first step, next other valuables • Companies interested • Resource boundaries for environmental science
• (PHA)
Picture source: ESA
Near-‐Earth asteroid? (What?)
• An asteroid, which could enter the neighborhood of Earth (asteroid belt further)
Apollos
Atens
Amors
A7ras (IEOs)
Research ques7on and methods
• Supply? • Demand? • Strategies? • Other sources?
Feasibility
Can the extrac+on of water from a NEO be seen feasible?
Distribu7on between classes by number
C 9%
Q 26%
S 36%
X 11%
others 18%
NEOs 2014 • Total of 11,665
• More informaBon known
from 1,690 • Taxonomy possible to
determine from 619
From the known NEAs, C asteroids have share of 0.7%
77
Distribu7on between classes by volume
!"#$%&!
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;-5<60"40.=00>".7?->-6@9"9572202"
• 166 km3 of C-‐asteroids • With 10 m-‐%
à 23 Gt of water
Theore7cal total mass and water mass of C-‐asteroids
Diameter (m)
Total massmin (t)
Total massmax (t)
Water massmin (t)
Water massmax (t)
10 650 1,230 55 245
50 81.3 * 103 153.2 * 103 6,900 30,600
200 52.0 * 105 98.0 * 105 4.4 * 105 19.6 * 105
Minimum density 1.38 g/cm3 Minimum water content 8.5 m-‐% Maximum density 2.60 g/cm3 Maximum water content 20 m-‐%
Poten7ally one million NEAs larger than 30 m
à expected propor7on of C-‐asteroids 10% à theore7cal amount of water substan7al
Use of water: Life support systems
• ISS: demand annually approximately 8.7 t for drinking, washing and oxygen produc7on
• Water recovery system drops the need to ≈ 3.1 t
• Mars mission of 500 days and 5 persons ≈ 35.5 t
Use of water: Propellant Diameter
(m) O2 massmin
(t)
O2 massmax (t)
H2 massmin (t)
H2 massmax (t)
10 49 218 6 27
50 6,100 27,200 770 3,400
200 393,100 1,742,500 49,100 217,800
• Reduc7on in launch mass
• Space debris removal
• Servicing, Recycling, Reusing • Taking control, possible reposi7on à life extension from 3 to 5 years
• Valuables or reusing parts
Use of water: Radia7on shielding
• Galac7c cosmic rays (GCR) • Solar par7cle events (SPE) • Hydrogen very effec7ve protec7on towards GCR and SPE due to high electron per nucleon ra7o
• NASA’s WaterWalls-‐concept
Theore7cal trajectories
• NASA’s Near-‐Earth Object Human Space Flight Accessible Targets Study (NHATS) with 1,232 targets – Δv (“effort needed”) – Total dura7on – Stay – Orbit condi7on code (OCC) (0= high, 9=low)
Theore7cal trajectories
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*+,'
-(./0''12'34#5,6'
78,,8(9'(:;(9,'
*+"$(!",-./"0!1$2"
*+"$%!",-./"0!1$2"
*+"3&!",-./"0!1$2"
*+"4#!",-./"0!1$2"
3&!",-./"0!542"
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40 t of water to LEO
Launch: Atlas V 80 t RP-‐1 3 t LH2 E = 4.1 TJ
Go to: ARRV SEP 40 kW E = 1 TJ
Fetch: E = 1.6 TJ
Safe storage: E = 0.6 TJ
L1 – LEO – L1: 3 * ARRV E = 3.3 TJ
Total: 12.3 TJ
FROM EARTH: 3 * Falcon 9 134 t of RP-‐1 E = 18.5 TJ
Conclusions and recommenda7ons
• Supply? • Demand? • Strategies? • Other sources?
Feasibility
Can the extrac+on of water from a NEO be seen feasible?
Reliability and costs should be determined next