about space elevator

1. The Space Elevator
… building our future

2. Space Elevator
SHIVAM GAUTAM
MECHANICAL 4th Yr
ROLL NO. 134054

3. WHAT IS SPACE ELEVATOR

4. SPACE ELEVATOR
• Basic description :The
space elevator is a cable
with one end attached to
the Earth and the other end
roughly 60,000 miles out in
space.
• Will be able to transfer
materials and eventually
humans into space for
much cheaper than it costs
now

5. Deployment Overview

7. THE COMPONENTS
The Ribbon
The Anchors
The Initial spacecraft
and the Climbers
The Power

8. 1.THE RIBBON: DESIGN

9. THE RIBBON: CONSTRUCTION

10. WHAT IS CARBON NANOTUBE?
Can be thought of as a
sheet of graphite (a
hexagonal lattice of
carbon) rolled into a
cylinder

11. TYPES OF CARBON
NANOTBES
• Classified mainly in two types:
1. SINGLE WALLED NANOTUBES
2. MULTI WALLED NANOTUBES
• OTHER RELATED STRUCTURES:
#TORUS
#NANOBUD
#GRAPHENATED CARBON NANOTUBES (g-CNTS)
#NITROGEN DOPED CARBON NANOTUBES (N-CNTS)
#PEAPOD
#CUP-STACKED CARBON NANOTUBES

12. SINGLE WALLED CNT
• Diameter :- 1 nanometer
• Band gap :- 0-2ev
• A one atom thick layer of
graphene into seamless cylinder .
• Their electrical conductivity
can show metallic or semiconducting
behaviour.

13. MULTIWALLED CNT
• Multi-walled nanotubes (MWNT)
consist of multiple rolled layers
(concentric tubes) of graphene.
• Interlayer distance :- 3.4 Å
• To describe structure of MWNT
there are two models:-
• 1. Russian doll model
• 2. Parchment model

14. OTHERS STRUCTURE
TORUS NANOBUD
PEAPOD CUP – STACKED CNT

15. WHY NANOTUBES
Fiber material Specific
Density
Young's
modulus(Tpa)
Strength
(Gpa)
Strain at
break(%)
Carbon
Nanotube
1.3 – 2 1 10 – 60 10
HS Steel 7.8 0.2 4.1 <10
Carbon fiber-
PAN
1.7 – 2 0.2 – 0.6 1.7 – 5 0.3 – 2.4
Carbon fiber-
Pitch
2 – 2.2 0.4 – 0.96 2.2 – 3.3 0.27 – 0.6
E/s-Glass 2.5 0.07 – 0.08 2.4 – 4.5 4.8
Kevlar-49 1.4 0.13 3.6 – 4.1 2.8
Material Thermal conductivity Electrical conductivity
Carbon Nanotube > 3000 10^6 – 10^7
Copper 400 6 x 10^7
Carbon fiber-Pitch 1000 2 - 8.5 x 10^6

16. CHEMICAL VAPOUR
DEPOSITION
• Involves heating a catalyst material to high temperatures in a tube
furnace and flowing hydrocarbon gas through the tube reactor
• The materials are grown over the catalyst and are collected when the
system is cooled to room temperature
• Key parameters are:
– Hydrocarbons
– Catalysts
– Growth Temperature
• CVD process involves the dissociation of hydrocarbon molecules
catalyzed by the transition metal, and the dissolution and saturation of
carbon atoms in the metal nanoparticle
• Both MWNT and SWNT can be grown by CVD methods
– MWNTs use acetylene gas for the carbon source and a growth
temperature between 600 – 800°C
– SWNTs use carbon monoxide or methane for a carbon source and a
much higher growth temperature (900 –1200°C)

17. CNT FABRICATION

18. ARC METHOD
• Carbon Atoms are evaporated by a plasma of Helium gas
that is ignited by high currents passed through opposing
carbon anode and cathode.
He Arc-Discharge
• Excellent Method for the production of both MWNT and
SWNT
• CNTs are obtained by controlling growth conditions
– Pressure of gas in discharge chamber
– Arcing Current on a collector outside the furnace zone

19. CNTS MANUFACTURER
•Carbon Solutions
•CarboLex
•Carbon Nanotechnologies, Inc.
•Fullerene International
Corporation
•Junye Nano Materials, Co.
•Luna Nanomaterials
•Luxtera
•Nanocs International
•Nanoledge
•Oxonica
•Showa Denka KK
•Deal International Inc.
•Micro Tech Nano, Inc
•Nano Carb Lab(NCL)
•NanoLab, Inc
•Nanostructured and
Amorphous Materials, Inc
•Nanosys
•Catalytic Materials LLC
•INPT

20. ANCHOR
 Anchor station is a mobile, ocean-
going platform identical to ones used
in oil drilling
 Anchor is located in eastern equatorial
pacific, 1500 miles from the
Galapagos island

21. ANCHOR

22. The initial spacecraft
 It is used to deploy the first
cable.
 The spacecraft will have
a large payload mass,
require a specific set of
mechanical actions, have a
short lifetime, and minimal
power, attitude control, and
communications
requirements.

23. CLIMBERS
 Climbers built with current
satellite technology
 Drive system built with DC
electric motors
 Photovoltaic array (GaAs or
Si) receives power from
Earth
 7-ton climbers carry 13-ton
payloads
 Climbers ascend at 200
km/hr
 8 day trip from Earth to
geosynchronous altitude

24. CLIMBERS

25. THE POWER BEAMING
• Free-electron lasers used
to deliver power
• Adaptive Optics on
Hobby-Eberly telescope
used to focus Earth-based
beams, (25cm spot @
1,000km altitude)
• Reduced power delivered
at high altitudes
compensated by reduced
gravitational force on
climber, (~0.1g)

26. Challenges
 Induced Currents: milliwatts and not a problem
 Induced oscillations: 7 hour natural frequency couples
poorly with moon and sun, active damping with anchor
 Radiation: carbon fiber composites good for 1000 years
in Earth orbit (LDEF)
 Atomic oxygen: <25 micron Nickel coating between 60
and 800 km (LDEF)
 Environmental Impact: Ionosphere discharging not an
issue
 Malfunctioning climbers: up to 3000 km reel in the
cable, above 2600 km send up an empty climber to
retrieve the first
 Lightning, wind, clouds: avoid through proper anchor
location selection
 Meteors: ribbon design allows for 200 year probability-
based life
 LEOs: active avoidance requires movement every 14
hours on average to avoid debris down to 1 cm
 Health hazards: under investigation but initial tests
indicate minimal problem
 Damaged or severed ribbons: collatoral damage is
minimal due to mass and distribution

27. Advantages
 Low operations costs - US$250/kg to LEO, GEO,
Moon, Mars, Venus or the asteroid belts
 No payload envelope restrictions
 No launch vibrations
 Safe access to space - no explosive propellants or
dangerous launch or re-entry forces
 Easily expandable to large systems or multiple
systems
 Easily implemented at many solar system locations

28. Applications
 Solar power satellites - economical,
clean power for use on Earth
 Solar System Exploration - colonization
and full development of the moon, Mars
and Earth orbit
 Telecommunications - enables extremely
high performance systems

29. REFERENCEES
• http://www.pbs.org/wgbh/nova/space/spac
e-elevator.html
• http://www.howstuffworks.com/space-
elevator.htm
• http://www.spaceward.org/elevator
• http://phys.org/news151938445.html
• http://nextbigfuture.com/2009/01/cambridg
e-making-carbon-nanotubes.html