The Space Elevator: An Exciting Challenge

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The Space Elevator An Exciting Challenge

• Tom Nugent
• Research Director
• LiftPort, Inc.
• tom.nugent_at_liftport.com

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Think Big!
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A Space Elevator?
Port of the Solar System
Railroad to space
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How Does It Work?

• Just like twirling a ball-on-a-string over your
  head

• Balance forces above and below GEO
• Taper ribbon cross-sectional area for constant
  stress
• Net tension in ribbon allows vehicles (Lifters)
  to climb into orbit

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The Liftport
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RibbonLifter
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Counterweight
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Deployment

• Seed ribbon
• 1 tonne capacity
• Assemble in LEO, boost to GEO via power beaming
• Lower one end of ribbon towards Earth, boost
  other end
• Gravity-gradient stabilization

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Why Build It? (1)

• Safety Reliability
• Rockets have 5 failure rate
• SE gives a gentle ride
• Reduced vibrations etc. for cargo

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Why Build It? (2)

• Economics
• Rockets are Expensive
• Ferries vs. Bridge, or Covered Wagon vs. Railroad
• Capacity
• SPS?
• Bigger satellites
• Real estate (GEO port)
• Profit!

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Why Now?

• Carbon nanotubes (discovered 1991) make the SE
  feasible
• High strength
• Low density

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Strength!

• Strength-to-weight is most important property
• Requires improvement of 11x-25x!
• Get mass reduction by factor of trillions
• What is appropriate safety factor?

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Research Questions (1)

• Lightning
• Wind
• Twist of ribbon
• Weight of precipitation
• Atomic oxygen
• Orbital Debris
• Deployment
• Power Beaming

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Research Questions (2)

• Elastic energy
• Cascading failure?
• Ribbon safety factor
• Learn from structural engineers, current systems

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Research Questions (3)

• Thermal flux
• Earth's shadow
• CTE mismatch between CNTs and matrix
• Electromagnetic interaction

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Research Questions (4)

• Lifter vehicle
• Endurance
• Multiple physical regimes
• Heat management
• Others
• Radiation damage to ribbon
• Ribbon inspection and position monitoring
• Adequate testing of pre-cursor components
• Cumulative damage
• Vehicle acceleration limits
• Alternate designs (e.g., balloon platform)

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Roadmap
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How Do We Tackle Questions?

• Piggyback on research in other fields
• Space tethers, laser launch, debris mitigation,
  weather forecasting, magnetosphere, material
  fatigue, etc.
• Volunteers
• Most current SE researchers
• Partner with interested researchers
• Collaborate on grant-writing
• Pay big for detailed engineering work

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Finding Solutions

• Partnering
• Universities professors, graduate students,
  undergrads, research staff
• Guidance
• Thesis topics
• Independent study projects
• Volunteers
• Interns and LiftPort in-house work
• Lets talk!

and more!
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Want More?

• To Learn More and Get Involved
• Sign up for our Newsletter
• Newsletter box at http//www.liftport.com
• Join our Forums
• http//www.liftport.com/forums/
• Buy our new book!
• Tell your friends and colleagues

www.LiftPort.com Tom.Nugent_at_LiftPort.com