Long-Duration Interplanetary Spacecraft: A Design Study

1
Long-Duration Interplanetary Spacecraft A
Design Study
Ryan HaugheyUndergraduateDept. of Aerospace
Engineering Texas AM 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.
• gt24 Month Trip Time
• 12 Crew Members
• Capable of Interplanetary Space Travel

4
Whats 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 DriversDetailed DesignCompetitive
Advantages

• Presentation Outline

7
Design DriversDetailed DesignCompetitive
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

10
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

11
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

12
Countermeasures Artificial Gravity
1
To avoid motion sickness, we must rotate below 4
rpm (while keeping the rotation radius as small
as possible)
13
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 cant
  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)

14
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

15
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

16
The crew has to breathe!
2
Atmospheric compositionpO2 22.7 /- 9 kPa(170 /- 10 mm Hg)
p(inert gas most likely N2) 26.7 kPa
pCO2 lt 0.4 kPa
pH2O 1.00 /- 0.33 kPa(7.5 /- 2.5 mm Hg)
Total pressure ½ atm
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What Shape?

• ½ Atm pressurization centrifugal loading ?
  Solids of revolution are the most efficient
  pressure vessels

1
Torus Minimum ratio of pressurized volume to
useful floor space Rotation axis axis of
maximum inertia ? Attitude is passively stable
Sphere Large ratio of pressurized volume to
useful floor space (projected area)
Long cylinder Axis of minimum inertia rotation
axis ? Energy dissipation results in disruptive
nutation Active attitude control of this one
more thing to go wrong
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How Much Space Do People and Plants Need?
Space use Surface arearequired,m2/person No. oflevels Projectedarea, m2 Estimatedheight, m Volume,m3/person
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 andentertainment 1 1 1 3 3
Storage 5 4 1 3.2 16
Mech. subsystemCommunication distr.switching equipment 0.5 1 0.5 4 0.2
Waste and water treatmentand recycling 4 1 4 4 16
Electrical supply anddistribution 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 processingcollection, 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
Total Projected area per person 40 m2 Total
Volume per person 1050 m3
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.
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Is a Complete Torus Too Roomy?
1
z, zb
?
2 r
R
y, yb
x, xb
With R70m, r5m and three floors Projected
area 10X2?RX3 12,600 m2 Enough for 315
people! But we only need to sustain 12 ..
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Solution Use only what you need!

• Embed the hab modules in a stiff, light tensioned
  cable, compressed column structure a proven
  approach to precision space structures.
• Cables carry most of the centrifugal loading
• Junctions are statically determinite, permitting
  accurate analysis
• Stiffness is provided in all six rigid body hab
  module degrees of freedom.
• Lowest vibration modes avoid frequencies that
  induce motion sickness
• Design is expandable by adding more hab modules
  and more supporting cables

• Note
• A truss and walkway connect the hab modules
  (with each other and with agrimodules)
• Cross truss and rotation axis column serve to
  give sufficient stiffness.
• Cross truss supports agg modules
• Propulsion engines located at tips of cross
  truss. Protects Hab and Agg modules from
  radiation. Provides control authority for both cm
  acceleration and rotation control

• 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

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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

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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
• 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 Sun-Earth system

E-L1 to S-L2 ?V12m/s, 50 days
1
122,720 km
L1
L2
Sun
L2
Earth-Moon Frame
Sun-Earth Frame
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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
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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) 4. Mine Amors and Apollos on the way
(3 years) Then see next slide
1 AU
26
Heteroclinic Transfer Between Exterior and
Interior Realms
1

1. Follow homoclinic exterior domain orbit to L2 on
   the stable manifold (green line, pointing down,
   left). Refurbish and repair at L2 Station
2. 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

1. Deliver cargo to Earth-Moon system. Meld into L1
   Lyapunov orbit, Exchange crew and refuel at L1
   Station.
2. 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
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) 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.
Forbidden zone
Apophis
Sun
3-2 resonance
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Design DriversDetailed DesignCompetitive
Advantages

• Presentation Outline

29
SystemTeams
Management PM Ryan Haughey Assistant PM Blaise
Cole
Budget Scheduling
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System Overview ArchitectureMichael 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

31
Moment of Inertia Overview
z
x,y,z axes Principal axes of inertia Ixx
203,300 MT-m2 Iyy 463,600 MT-m2 Izz 641,300
MT-m2 Total Mass 350MT
15MT
18MT
23MT
y
x
46MT (total)
Izz is largest moment of inertia rigid body
nutation of the spin axis due to energy
dissipation coupling is suppressed
4MT
32
Architecture Overview
Nuclear Reactor and Engine
Water Ballast
40 m
70 m
70 m
17 m
40 m
Living Area
Agriculture Pods
Airlock/Dock
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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

34
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 Living Pod Summary
Floor Area per Pod (m2) 79.48
Number of Pods 4
Number of Crew 12
Floor Area per Person (m2) 26.49
Stanford Study per Person Requirement2 (m2) 19.83
Agriculture Pod Summary Agriculture Pod Summary
Floor Area per Pod (m2) 142.98
Number of Pods 2
Number of Crew 12
Floor Area per Person (m2) 23.83
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

40
40
System Overview Life SupportMegan 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

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 Aeroponics Farming Tower Gardens
Height (m) 1.83
Base (m2) 0.58
Number of Towers 12
Plants per Tower 28
Max Plant Output 336
Stored Farming (12 people, 2 years) Stored Farming (12 people, 2 years)
Total Stored Mass (kg) 8165
Total Stored Volume (m3) 13
Stored food consists of all which can not be
grown in tower gardens. Includes meats, grains,
sugars, salts, milk
Aeroponics Farming Shelf 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)

Water Summary 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) 1782 6.51 4.42
Total 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 Mitigation Summary
Solid Waste Production (kg/person/day)3 0.2
Number of Crew 12
Daily Waste Production (kg/day) 2.4
Waste Processor Performance (kg/unit/day)4 0.43
Number of Processors 10
Waste Capacity (kg/day) 4.3
Excess Waste Handling (kg/day) 1.9
Liquid Waste Migitation Summary Liquid Waste Migitation Summary
Liquid Waste Production (l/person/day)5 2
Gray Water Production (l/person/day)6 19
Number of Crew 12
Daily Waste Production (l/day) 252
Water Processor Performance (l/unit/day)7 140
Number of Processors 2
Waste Capacity (l/day) 280
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
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
• Waste used as fertilizer

48
48
System Overview Stress ThermalAlex Herring,
Brendon Baker, Scott Motl, Keegan Colbert, James
Wallace, Travis Ravenscroft

• Goal
• Develop a stable structure capable of
  withstanding loading profile
• Challenges
• Rotational Loading Rigidity
• Truss design
• Vibration Mitigation
• Cable design and placement
• Thermal Environment Management

49
Structural Layout Tensioned Cable

• 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

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 crafts 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 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
54
System Summary Stress Thermal

• Goal
• Develop a stable structure capable of
  withstanding loading profile
• Findings
• Tensioned-cable structure reduces
• truss mass, vibration
• Passive cooling can accomplish
• thermal control, with minor support

55
55
System Overview PropulsionKyle Monsma,
Benjamin Morales, Carl Runco, Paul Schattenberg,
Mark Baker, Steven Swearingen

• Goal
• Provide sufficient thrust to transport space
  craft into interplanetary travel
• Challenges
• Mission duration
• Long-duration thrust development
• Attitude control

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

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

Image credit University of Washington, Dept. of
Aerospace Engineering
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 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
 
60
60
System Summary Propulsion

• Goal
• Provide sufficient thrust to transport space
  craft into interplanetary travel
• Findings
• Low thrust, high-Isp engine (ELF)
• Xeon fuel
• Deflect engines to obtain spin

61
61
System Overview PowerCollin Marshall, Andrew
Tucker, Carl Mullins, Jack Reagan, Colby Smith,
Andrew Nguyen

• Goal
• Provide reliable electrical power to meet
  spacecraft systems requirements
• Challenges
• High power requirements by engines
• Mass, size constraints
• Radiation management
• System redundancy

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
• 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

To center of craft
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 Solar Panel Array Specifications
Panel Efficiency11 0.29
Panel Area per Pod (m2) 16.7
Panel Mass per Pod (kg) 176
67
67
System Summary Power

• Goal
• Provide reliable electrical power to meet
  spacecraft systems requirements
• Findings
• Dynamic cycle power generation
• Nuclear reaction heat production
• Solar panels provide back up power

68
68
System Overview Budget SchedulingBlaise
Cole, Kevin Davenport, Lisa Warren

• Goal
• Track the mass, power, and monetary requirements
  for the system, and prepare a feasible deployment
  plan
• Challenges
• Developing funding structure
• Creating deployment schedule

69
Systems Overview
System Mass (MT)
Architecture 235.4
Structure 7.0
Propulsion 40.8
Power 28.3
Life Support 34.9
Total 346.4
System Power (MW)
Architecture 0.35
Propulsion 1.9
Life Support 0.3
Power Required 2.56
Power Produced 3.02
70
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 RD of technology
• Develop LEO research, tourism platform for
  further partnerships revenue streams

71
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

72
Design DriversDetailed DesignSummary

• 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

74
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

75
Acknowledgements

• Dr. David Hyland
• Department of Aerospace Engineering, Dwight Look
  College of Engineering, Texas AM University
• The Fall 2012 AERO 426 team leaders and team
  members

76
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  0.
• 10 Webb, J. A., Gross, B. J., A Conceptual
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  Space 2011, Idaho National Laboratory, Feb. 2011.

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Questions?
Thank you very much for your time!