Transcript Document

1
Long-Duration Interplanetary
Spacecraft:
A Design Study
Ryan Haughey
Undergraduate
Dept. of Aerospace Engineering
Texas A&M University
2
Project Overview
 Design project for aerospace engineering students in final year of
undergraduate program
 Subgroups developed initial goals, which were later integrated into
a final spacecraft
 Presented to board of industry and academic reviewers in Dec.
2012
3
Mission Statement
“To expand the domain of humanity beyond the earth for the
betterment, preservation, and advancement of all humankind by
creating a self-sustaining, mobile habitat that ensures the physical and
psychological well-being of its inhabitants.”
>24 Month Trip Time
12 Crew Members
Capable of Interplanetary Space Travel
4
What’s the Purpose?
 Scientific
 Advance the state of the art in diverse technological areas
 Innovations for space usually have important terrestrial
applications
 Economic
 Mining of asteroids could yield many valuable materials
 High demand for space tourism, research opportunities
 Exploratory
 Spark a new age of enthusiasm for the sciences
 Inspire next generation of scientists and explorers
5
Ultimate goal
 Attain economic viability and sustainability of the interplanetary
habitat through a range of revenue-generating activities, primarily
mining of asteroids
6
Design Drivers
Detailed Design
Competitive Advantages
Presentation Outline
7
Design Drivers
Detailed Design
Competitive Advantages
Presentation Outline
8
Design Goals
 Elements of a viable system
 Livability – Crew must be able to function, survive
 Practicality – Magic solution will not appear, must deal with
proven feasibility of technology
 Modularity – Assembly must be simple, repairs must be efficient,
expansion must be an option
9
Challenges of a Interplanetary
Space
 Physiological
 Physiological
 Weightlessness
 Livability
 Radiation
 Cost barriers to entry
Design Driver: Physiological Factors in Prolonged
Spaceflight
 No human being has ever traveled into interplanetary
space
 In 5 decades of manned spaceflight, our understanding of
physiological change during long duration missions
remains limited
 Physiological impacts are significant and varied
 During the course of a mission: 0-g effects (bone loss,
muscle loss, immune system impairment, etc.),
radiation exposure and immunological depression
 Return to Earth: cardiovascular de-conditioning and
orthostatic intolerance
 Both in-flight and post-flight physiological issues must be
countered
Design Driver: Countering 0-g Effects
 There is no completely satisfactory approach to
countering 0-g effects aside from sustained artificial
gravity.
 We do not know how much “g” is required to maintain
human health indefinitely (besides zero g = bad, and
one g = good)
 We will not know the answer to this for a long time, since
long term experiments are required.
 Therefore, in this design study, we require:
 1 g artificial gravity.
 Acceptable levels of Coriolis effects
 Exposure to 1g almost all the time
Countermeasures – Artificial Gravity
1
To avoid motion sickness,
we must rotate below 4
rpm (while keeping the
rotation radius as small
as possible)
Onset of
motion
sickness
Comfort
zone
4 rpm
Artificial gravity
becomes more “normal”
with increasing radius
Physiological Factors  Size and Rotation Rate
1 g artificial gravity and acceptable levels of
Coriolois forces motivate:
 Rotation rate = 3.5 rpm
 Rotation radius = 70m
(Thus max dimension can’t be less than 140m)
Exposure to 1g almost all the time means entire
s/c must rotate (a separate wheel with an
attached zero-g component is not practical)
Design Driver: Interplanetary Space Environment
 High levels of radiation present in interplanetary space
 Material must limit radiation exposure to levels on par
with ISS astronauts
 Micrometeorite protection must also be included
 Livable temperature must be maintained
Design Driver: Mass
 Support needed to keep structure together
 Launch costs are around $2,000 per pound of material
 Standard trusses would add unnecessary mass;
alternative solution needed
The crew has to breathe!
2
Atmospheric composition
pO2
22.7 +/- 9 kPa
(170 +/- 10 mm Hg)
p(inert gas; most likely N2)
26.7 kPa
pCO2
< 0.4 kPa
pH2O
1.00 +/- 0.33 kPa
(7.5 +/- 2.5 mm Hg)
Total pressure = ½ atm
What Shape?
 ½ Atm pressurization & centrifugal loading  Solids of
revolution are the most efficient pressure vessels
1
Sphere
Long cylinder
Large ratio of
pressurized
volume to useful
floor space
(projected area)
Axis of minimum inertia =
rotation axis
 Energy dissipation results
in disruptive nutation
Active attitude control of this
= one more thing to go wrong
Torus
Minimum ratio of
pressurized volume to
useful floor space
Rotation axis = axis of
maximum inertia 
Attitude is passively
stable
How Much Space Do People and Plants Need?
Space use
Surface area
required,
m2/person
No. of
levels
Projected
area, m2
Estimated
height, m
Volume,
m3/perso
n
Residential
49
4
12
3
147
Offices
1
3
0.33
4
4.0
Assembly rooms &
radiation storm shelter
1.5
1
1.5
10
15
Recreation and
entertainment
1
1
1
3
3
Storage
5
4
1
3.2
16
Mech. subsystem
Communication distr.
switching equipment
0.5
1
0.5
4
0.2
Waste and water treatment
and recycling
4
1
4
4
16
Electrical supply and
distribution
0.1
1
0.1
4
0.4
Miscellaneous
2.9
3
1
3.8
11.2
Subtotals
65.0
-
21.43
-
212.8
Agricultural space
(a) Plant growing areas
44
3
14.7
15
660
(b) Food processing
collection, storage, etc.
4
3
1.3
15
60
(c) Agricultural drying area
8
3
2.7
15
120
Totals
121.0
-
40.13
-
1052.8
Note: This is Table 3.2 of cited reference 2, but with several categories of space removed owing to the
limitations of a 12-person vessel. The spaces removed are: Shops, schools and hospitals, public open space
(500 m3) service industry space, transportation and animal areas.
Total Projected
area per
person
= 40 m2
Total Volume
per person
= 1050 m3
Is a Complete Torus Too Roomy?
1
z, zb

R
2r
y, yb
x, xb
With R=70m, r=5m and three “floors”:
Projected area ~ 10X2RX3 ~ 12,600 m2
Enough for 315 people! But we only need to
sustain 12 …..
Solution: Use only what you need!
• Modular pod configuration
• Attach modules as needed to support volume requirements
• Addressing new challenges
• Vibration damping using tensioned cables and compression
columns
• Natural frequencies causing motion sickness are avoided
• Capitalizing new advantages
• Engines may be placed along outer radius of structure
without interfering with livable area
21
Mission Requirements
 Minimize delta-v required for transportation
 2-3 year mission duration
Solution
 Constant thrust departure from LEO to Lagrange points
 “Grand Tour” of interplanetary space in Earth – Sun system
 Drift along energy boundary of Earth-Sun system with little to no
delta-v
 Orbit cycle used by many asteroids, could allow for rendezvous
and mining
22
Initial Deployment: Spiral out to E-M L1
1

Start in 300 km circular
orbit about Earth
 Thrust always aligned
with the velocity vector
 Full thrust up until 11
days and coasting to
L1 thereafter
Spiral out to a coasting
trajectory to the E-M L1
“throat”.
 Meld into the Lyapunov
orbit of L1 Station and
refuel
385  103 km
Propellant mass: 21 MT
Trip duration: 5.6 months
23
From E-M L1 to S-E L2: Start of the First Grand Tour
 After refueling, leave L1
on the outward invariant
manifold.
 Swing by the Moon and
exit the E-M L2 throat in
time to meld with a
heteroclinic orbit leading to
the Sun-Earth L2
 Take one turn around the
Lyapunov orbit and enter the
external domain of the SunEarth system
L1 Lyapunov
Orbit
Moon
E-L1 to S-L2: V=12m/s, 50 days
Orbit of the
Moon
122,720 km
L1
Sun
Earth-Moon Frame
Sun-Earth Frame
L2
L2
1
24
Asteroid Mining Tours: Exterior Realm
1
1.
Drop off cargo at L1 Station. Leave L1 Lyapunov orbit.
Follow heteroclinic orbit to L2 (pink line, left to right)
(drop off cargo at Earth-Moon system)
2.
Meld into L2 Lyapunov orbit, follow for ¾ of a period,
then follow the unstabile manifold (green line, heading
down)
L1
L2
3.0 million km
Sun-Earth Frame
25
Through S-E L2 to the Grand Tour of the Exterior Realm
1
3. Follow the
homoclinic,
exterior domain
orbit (green path
issuing from L2
and going
clockwise)
Apophis
4. Mine Amors and
Apollos on the way
(3 years)
Then: see next
slide
Sun
3-2 resonance
1 AU
26
Heteroclinic Transfer Between Exterior and Interior Realms
1
5.
Follow homoclinic exterior domain orbit to L2 on the stable
manifold (green line, pointing down, left). Refurbish and
repair at L2 Station
6.
Meld into L2 Lyapunov orbit, follow for ½ of a period, then
follow the heteroclinic orbit to L1 (pink line, right to left).
L1
L2
3.0 million km
7.
Deliver cargo to Earth-Moon system. Meld into L1 Lyapunov
orbit, Exchange crew and refuel at L1 Station.
8.
Follow Lyapunov orbit for one period, then follow the
homoclinic interior domain orbit (blue line heading to the left).
27
Through S-E L1 to the Grand Tour of the Interior Realm
1
Forbidden
zone
Apophis
9. Follow the
homoclinic, interior
domain orbit (red
path issuing from L1
and going counter
clockwise)
10. Mine Atens and
Apollos on the way
(two years)
Sun
3-2 resonance
11. Then follow the
stable manifold to L1
(blue line in previous
slide, heading to the
right).
12. Refuel and
exchange crew at L1
station.
Go to step 1 and
repeat.
28
Design Drivers
Detailed Design
Competitive Advantages
Presentation Outline
29
System
Teams
Management
PM: Ryan Haughey
Assistant PM: Blaise Cole
Budget & Scheduling
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
30
System Overview – Architecture
Michael Pierce, Paola Alicea, Terry Huang, Luis Carrilo,
Christopher Roach, Mario Botros
Goal:
Synergize design concepts to meet functional requirements
Challenges:
 Physiological: radiation, bone loss, air
 Psychological: confinement, productivity
 System stability
Management
Budget & Scheduling
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
Moment of Inertia Overview
z
15MT
x,y,z axes = Principal
axes of inertia
18MT
Ixx = 203,300 MT-m2
Iyy = 463,600 MT-m2
Izz = 641,300 MT-m2
23MT
Total Mass = 350MT
y
x
46MT
4MT
(total)
Izz is largest moment
of inertia; rigid body
nutation of the spin
axis due to energy
dissipation coupling
is suppressed
Architecture Overview
33
Inflatable Living Pod
 Modeled on NASA Transhab study (Inflatable pod)
 Nearly 2 dozen layers in 1-ft thick skin provide thermal, ballistic, and
radiation protection
 Radiation Protection: conservatively 30 rem/yr (ISS is 50 rem/yr)
 Ballistic Protection: Micrometeorite and Orbital Debris Shield
 Each pod provides living space for four crew members
6m
32.5 m
8.4 m
10 m
13 m
Auxiliary pods
 Identical to living pods
 Low-gravity environment: sufficient to allow for proper survival by plants
 One pod optimized for food growth, other for oxygen generation
35
Engine & Power Pods
 Provides housing for power plant and engine
 Power plant selected as nuclear reactor (further discussion later)
 Shielding for nuclear reactor assists structure in deep space
radiation and micrometeorite protection
36
Water Ballast
 Stores system water
 Displace water along structure length to adjust
moments of inertia
 Thermal management of water could be accomplished
using heat pipes from power source
 High levels of redundancy needed to protect against
micrometeorite impacts on water column
37
Docking Module
 Standardized module allows for docking of rendezvous craft
 ISS PIRS module may serve as good model
 Combination docking port and airlock
Image credit: NASA
38
Floor Space Summaries
Living Pod Summary
Agriculture Pod Summary
Floor Area per Pod (m2)
79.48
Floor Area per Pod (m2)
142.98
Number of Pods
4
Number of Pods
2
Number of Crew
12
Number of Crew
12
Floor Area per Person (m2)
26.49
Floor Area per Person (m2)
23.83
Stanford Study per Person
Requirement2 (m2)
19.83
Stanford Study per Person
Requirement2 (m2)
18.70
39
System Summary – Architecture
Goal:
Synergize design concepts to meet functional requirements
Findings:
 Modular, inflatable habitation pods
 Water ballast
 Locate power, engine away from
the axis of rotation
Management
Budget & Scheduling
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
40
System Overview – Life Support
Megan Heard, Sarah Atkinson, Mary Williamnson, Jacob Hollister,
Jorge Santana, Olga Rodionova, Erin Mastenbrook
Goal:
Create an environment conducive to healthy human functions
with minimal re-supply for duration of mission
Challenges:
 Crew nutrition & health
 Water recycling & distribution
 Waste Management
 Oxygen regeneration
Management
Budget & Scheduling
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
41
Crew Nutrition
 Modeled on diet of residents of Greek island of Ikaria, noted for
exceptional health and longevity
 For missions past 21 months, more practical to self-sustain food
 Some portions of diet require bringing food along (meats, oils)
 Proposed solutions:
 Aeroponically grow food in low-gravity agriculture pods
 Maintain cold storage for stowed perishable food
Image credit: Tower Garden
42
Nutrition Logistics
Aeroponics Farming: Tower Gardens
Stored Farming (12 people, 2 years)
Height (m)
1.83
Total Stored Mass (kg)
8165
Base (m2)
0.58
Total Stored Volume (m3)
13
Number of Towers
12
Plants per Tower
28
Max Plant Output
336
Stored food consists of all which can
not be grown in tower gardens.
Includes: meats, grains, sugars, salts,
& milk
Aeroponics Farming: Shelf
Total Area (m2)
6.69
Tower gardens used to grow range of
fruits, vegetables, and herbs.
Shelf used to grow potatoes
Combination of produce and stored
food allow for full sustainment of crew
for around 3 years
43
Water Treatment
 Must handle waste-water and gray-water
 Prevent disease development
 Effective water recycling becomes advantageous after 0.5 months
 Proposed solution
 Utilize ECLSS system currently in place on ISS (~95% efficient)
Mass (kg)
Volume (m3)
Power (kW)
Water for Humans:
5100
5.1
N/A
Water for Algae:
7920
7.92
N/A
Water for Agriculture:
1514
1.514
N/A
ECLSS Water Recycling
System
(2 units):
Total:
1782
6.51
4.42
Water Summary
14801.87
18.81
4.42
44
Waste Management
 Isolation of outpost requires full effective recycling
 Human waste can serve as effective crop fertilizers, reducing need
for artificial fertilization (added mass)
 Proposed solutions
 Closed-loop system with high-efficiency composters & ECLSS
water filtration system
 Tie-in to agriculture system for fertilization
45
Waste Summary
Solid Waste Mitigation Summary
Solid Waste Production (kg/person/day)3
Number of Crew
Daily Waste Production (kg/day)
Waste Processor Performance
(kg/unit/day)4
Liquid Waste Migitation Summary
0.2
Liquid Waste Production
(l/person/day)5
2
12
2.4
Gray Water Production
(l/person/day)6
19
Number of Crew
12
0.43
Daily Waste Production (l/day)
252
4.3
Water Processor Performance
(l/unit/day)7
140
1.9
Number of Processors
2
Waste Capacity (l/day)
280
Number of Processors
10
Waste Capacity (kg/day)
Excess Waste Handling (kg/day)
Excess Waste Handling (l/day)
28
46
Oxygen Regeneration
 Standard CO2 scrubbing and Oxygen Generation Systems consume
water in production of oxygen
 After 21 months, a closed-loop system becomes more efficient
 Proposed solution
 Convert CO2 into O2 using green algae (Spirulina) tanks
 Mechanically filter other impurities
 Back-up system (in case of disease or catastrophic failure) would
be standard OGS/C02 scrubber similar to ISS
Image Credit: California State University – Long Beach
47
System Summary – Life Support
Goal:
Create an environment conducive to healthy human functions
with minimal re-supply for duration of mission
Findings:
 High-nutrition, efficient diet
 Recycle, grow as much as possible
 Multipurpose systems
Management
Budget & Scheduling
Life
Support
 Waste used as fertilizer
Stress &
Thermal
System
Architecture
Power
Propulsion
48
System Overview – Stress & Thermal
Alex Herring, Brendon Baker, Scott Motl, Keegan Colbert,
James Wallace, Travis Ravenscroft
Goal:
Develop a stable structure capable of withstanding loading
profile
Challenges:
Management
 Rotational Loading & Rigidity
 Truss design
Budget & Scheduling
 Vibration Mitigation
 Cable design and placement
Life
Support
 Thermal Environment Management
Stress &
Thermal
System
Architecture
Power
Propulsion
49
Minimum Breaking Load (N)
Structural Layout: Tensioned Cable
300000
250000
200000
150000
100000
50000
0
0
0.005
0.01
0.015
Cable Diameter (m)
 Cables connect pods in rotation plane to central column
 Transfers centrifugal loads from rotation plane
 Significantly reduces need for trusses, total structure mass
 Manages vibration propagation
 Total compressive force: 782 kN
 Vibration mitigation drives cable size
0.02
50
Why such a complicated design?
 Another structural configuration: “Bola”
 Habitation areas connected by cable in rotation
 Suited to small structures, with few crew members
 Scale, mass of current structure would cause serious vibration
problems
 Tensioned cable with column gives structural rigidity in all 6 rigid
body DOFs
 Additional benefits
 Thrust located off the spin axis
 More maneuverable, allows for easier docking
 Much more expandable
 Pods can be more easily located at intermediate points in structure
51
Structural Rigidity
 Trusses needed to maintain craft’s shape, operate in
case of no centrifugal loading (much lower loads)
 Dimensions of structure require advanced materials
to minimize weight
 Proposed solutions:
 Composite (carbon-fibre) truss structure
 Outer connecting tubes enclose truss, prevents
outgassing & radiation degradation of composite
52
Vibration Mitigation
 Torus has been segmented, resulting in vibration instability
 Cable dimension driven by vibration mitigation, not centrifugal
loading
 Failing to address vibrations could result in structure shaking itself
apart
 Augment tension cables to mitigate vibration in other planes
 Avoid natural frequencies which induce motion sickness (0.05 – 0.8
Hz), 8 Hz (need more detailed model to address)
Cable Sizing Summary
X-translation mode minimum size (cm)
2
Y-translation mode minimum size (cm)
0.8
X-rotation mode minimum size (cm)
0.8
53
Thermal Management
 Nuclear reactor will produce large amounts of waste heat
 Near constant exposure to solar radiation once in deep space
 Simple white exterior to living pods renders a temperature on order
of -60oF
 Proposed solution
 Black/white surface coating combination (43% white, 57% black)
passively raises temperature to comfortable levels
 Radiator of around 200 m2 sized using Idaho National Labs
CERMET study (design basis for nuclear reactor)10
 Heat pipes convey additional heat throughout structure to utilize
as needed
54
System Summary – Stress & Thermal
Goal:
Develop a stable structure capable of withstanding loading
profile
Findings:
Management
 Tensioned-cable structure reduces
truss mass, vibration
Budget & Scheduling
 Passive cooling can accomplish
thermal control, with minor support
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
55
System Overview – Propulsion
Kyle Monsma, Benjamin Morales, Carl Runco, Paul Schattenberg,
Mark Baker, Steven Swearingen
Goal:
Provide sufficient thrust to transport space craft into
interplanetary travel
Challenges:
Management
 Mission duration
 Long-duration thrust development
Budget & Scheduling
 Attitude control
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
56
Engine Selection
 Continuous thrust system is most practical
 Electrodeless Lorentz Force (ELF) thrusters are emerging as
(relatively) high thrust, high Isp engine at a low weight & size
Engine Comparison
ELF8
VASIMR9
Engine Mass (MT)
3.8
7.6
Thrust (N)
66.5
47.5
Fuel Mass (% total)
8.74
7.84
Burn Time (days)
279
389
57
ELF Operation & Fuel
Image credit: University of Washington,
Dept. of Aerospace Engineering
Xe
5.894
3.057
1,839
Kr
3.749
2.413
2,891
 Xeon provides maximum
efficiency
 Xeon has greater compatibility
with existing spacecraft
technologies
58
Spin-up & Attitude Control
 Need to attain 3.5 RPM for 1g conditions in given craft
 Engines are mounted on edge of rotation plane, allowing gimballing
to combine spin and forward propulsion
 Proposed solution:
 During transit to Lagrange point, angle both engines to produce
rotation
 CMGs could also be used to provide heading maintenance
59
Spin-Up Detail
Properties Summary
Total Mass (MT)
350
Principle Moment of Inertia (kg
m2)
6.63 E8
Required Angular Velocity (rpm)
3.5
Moment Arm (m)
70
Angle & Burn Time vs. Thrust
50
45
40
35
30
25
20
15
10
5
0
Angle (Degrees)
Burn Time (Days)
0
10
20
30
Thrust (N)
40
50
60
60
System Summary – Propulsion
Goal:
Provide sufficient thrust to transport space craft into
interplanetary travel
Findings:
Management
 Low thrust, high-Isp engine (ELF)
 Xeon fuel
Budget & Scheduling
 Deflect engines to obtain spin
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
61
System Overview – Power
Collin Marshall, Andrew Tucker, Carl Mullins, Jack Reagan, Colby
Smith, Andrew Nguyen
Goal:
Provide reliable electrical power to meet spacecraft systems
requirements
Challenges:
Management
 High power requirements by engines
 Mass, size constraints
Budget & Scheduling
 Radiation management
 System redundancy
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
62
Powerplant
 Estimated power requirements around 2
MWe
 Solar array would be prohibitively large and
expensive
 INL CERMET study demonstrated conceptual
feasibility of space nuclear reactors of this
rating10
 Emergency power must be available for
sustaining limited life support functions in
event of outage
 Power distributed using similar system to ISS
Image credit (modified):
Boeing Defense, Space &
Security
63
Reactor Core
 2 separate reactors placed on opposite arms of ship
 Each reactor supports minimum power requirements
 Location near engine reduces transmission cable mass
 Passively stable with active control rods
 Allows for variable power output
 Conserves fuel and reduces overall mass
64
Shielding & Power Generation
 Be-W-LiH Layered Shielding covers broad spectrum protection
 Required thickness: 0.28m; mass of 1,450 kg per reactor
 Shadow shielding – Only shield craft needing protection
To center of craft
 Power generated with standard Brayton cycle
 High efficiency due to near 0K heat sink
 Helium is working fluid
 No regeneration
 Each reactor-turbine combination produces
1.5 MWe
 Heat pipes circulate waste heat around structure
Note: Cut-away view,
shield is
hemispherical
65
Power Conversion
Power Conversion Specifications10
Turbine Inlet Temperature (K)
1500
Pressure Ratio
15
Specific Mass (kg/kWe)
7.67
Total Mass (kg)
23,000
Efficiency
52%
Total thermal output (kWt)
5770
Total electrical output (kWe)
3000
Total waste heat (kWt)
2770
66
Emergency Power
 Solar panels capable of providing minimum life-support functionality
paired with each pod
 Back-up OGS system & heating will require 20 kW
Solar Panel Array Specifications
Panel Efficiency11
0.29
Panel Area per Pod (m2)
16.7
Panel Mass per Pod (kg)
176
67
System Summary – Power
Goal:
Provide reliable electrical power to meet spacecraft systems
requirements
Findings:
Management
 Dynamic cycle power generation
 Nuclear reaction heat production
Budget & Scheduling
 Solar panels provide back up power
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
68
System Overview – Budget & Scheduling
Blaise Cole, Kevin Davenport, Lisa Warren
Goal:
Track the mass, power, and monetary requirements for the
system, and prepare a feasible deployment plan
Challenges:
Management
 Developing funding structure
 Creating deployment schedule
Budget & Scheduling
Life
Support
Stress &
Thermal
System
Architecture
Power
Propulsion
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Systems Overview
System
Mass (MT)
System
Power (MW)
Architecture
235.4
Architecture
0.35
Structure
7.0
Propulsion
1.9
Propulsion
40.8
Life Support
0.3
Power
28.3
Power Required
2.56
Life Support
34.9
Total
346.4
Power Produced 3.02
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Funding
 Program would have extremely high costs for full integration
 Significant levels of government support would be unlikely,
undesirable due to loss of control
 Very risky nature of project would make significant levels of debt
unattainable, equity can lose direction
 Proposed solution:
 Use bootstrapping plan: start developing core components of craft
with terrestrial applications; provides revenue stream while
supporting further R&D of technology
 Develop LEO research, tourism platform for further partnerships &
revenue streams
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Deployment
 Significant number of launches would be required to deploy full craft
 Assembling at Lagrange point would be extremely difficult and
impractical
 Proposed solution:
 Assemble the structure in LEO, use as platform for research and
tourism
 After built, transfer to Lagrange point (while unmanned)
 Crew rendezvous with craft at Lagrange point, mission starts at
this point
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Design Drivers
Detailed Design
Summary
Presentation Outline
73
Design Goals
 Livability
 Artificial gravity, radiation shielding, diet ensure long-term health
 Internal architecture provides psychological comfort
 Practicality
 All technology grounded in present or near-future developments
 Modularity
 Assembly, repairs simple due to common pod
 Can incrementally grow station by adding modular pods
 Potentially attain full torus
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Potential Applications
 Asteroid mining (would need further development of additional
spacecraft for use in mining)
 Space tourism (deep space or near-earth)
 Debris removal and recycling
 Scientific research platform
 Permanent space station at Lagrange point
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Acknowledgements
 Dr. David Hyland
 Department of Aerospace Engineering, Dwight Look College of
Engineering, Texas A&M University
 The Fall 2012 AERO 426 team leaders and team members
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Sources
1
Hyland, David, “Class Lectures,” AERO 426, Texas A&M University, Fall 2012.
2 R.D.
Johnson, C Holbrow, editors, Space Settlements: A Design Study, NASA, SP-413, Scientific and Technical.
3
“Feces,” Encyclopedia Brittanica Online Edition, 2013.
4
Oshima, T., Moriya, T., Kanazawa, S., Yamashita, M., “Proposal of Hyperthermophilic Aerobic Composting Bacteria and Their Enzymes in
Space Agriculture,” Biological Sciences in Space, Vol. 21 No.4, 2007.
5 “Urinalysis,”
Mercer University School of Medicine. 1994-2012 [http://library.med.utah.edu/WebPath/webpath.html#MENU].
6
Johnson, David, “Graywater Treatment and Graywater Soil Absorption System Designs for Camps and Other Facilities,” Alaska Department
of Environmental Conservation, May 2005.
7
Beasley, Dolores, “NASA Advances Water Recycling for Space Travel and Earth Use,” NASA News, Nov. 2004
8 Slough,
J., Kirtley, D., Weber, T., “Pulsed Plasmoid Propulsion: The ELF Thruster,” 31st International Electric Propulsion Conference. Sept.
2009.
9 Ad
10
Astra Rocket Company, Company Website, 2009-2013, [http://www.adastrarocket.com/aarc/VX200].
Webb, J. A., Gross, B. J., “A Conceptual Multi-Megawatt System Based on a Tungsten CERMET Reactor,” Nuclear and Emerging
Technologies for Space 2011, Idaho National Laboratory, Feb. 2011.
11 Gaddy,
Edward M., "Cost performance of multi-junction, gallium arsenide, and silicon solar cells on spacecraft," Photovoltaic Specialists
Conference, 1996., Conference Record of the Twenty Fifth IEEE, IEEE, 1996.
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Thank you very much for your time!
Questions?