Bioengineering 155 Group Presentation Spring 2004

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Emerging Possibilities in Interstellar
Travel Investigating the Potential Development
and Operation of Worm Holes, Warp Drive, and
Solar Sails to Further Mans Exploration of Space
Bioengineering 155 Group PresentationSpring
2004 University of California BerkeleyPrepared
by Andy Chiang, Bridgit Dubrall, Charlene
Kemmerer, Terry Ma, Neil Parikh, and Maelene Wong
Group 1
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Exploring The Solar System Searching for
possible life, alternative living environments,
and resources in solar system.Expanding our
knowledge and trying to understand the universe.
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Outside of Solar System
Interstellar Travel

Travel between or among the stars.
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Early 1500s Leonardo da Vinci
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1903 Orville and Wilbur Wright
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Rocket Technology and Aviation in Early 1900s
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Wernher Von Braun
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1971 Salyut
1957 Laika
1961 Yuri Gagarin
1957 Sputnik I
1969 Apollo 11
The Space Race
1958 NASA
1958 Explorer I
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What are our limitations in space travel? Can we
travel faster and further in space?
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Rockets
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Space Travellets try rockets!!
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How do they work?

• Use a propellant (solid, liquid, composite)
• In a combustive process, propellant is ignited,
  burns, and is released posteriorly
• Gases produced provide propulsive force for
  rocket

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Consider the Forces

• Three main forces which affect rockets usage in
  space travel
• 1) Thrust
• 2) Aerodynamic
• 3) Gravitational

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Maybe, try using different propellants

• Solid
• Oxidizer Ammonium Perchlorate
• Fuel Aluminum Powder
• Beryllium Powder
• Liquid
• Oxidizer Liquid Oxygen O2
• Fuel Liquid Hydrogen H2
• Performance can be compared based on
• Specific Impulse
• Thrust
• Effect Exhaust Velocity

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Maybe, make different propulsion systems?

• Cold gas
• Bipropellant
• Hybrid
• Electrical
• Nuclear
• Laser

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Keys to Using Rockets For Travel

• Propulsive force must be generated by expelling
  least mass possible (greater exhaust velocity)
• Propulsion system must be simple enough to be
  used in space avoiding possible complications
• (according to NASA)

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• According to the Breakthrough Propulsion Project
  we need the following three breakthroughs in
  order to make interstellar space travel a
  reality
• Discover new propulsion methods that eliminate or
  dramatically reduce the need for propellant.
• Discover how to attain the ultimate achievable
  transit speeds to dramatically reduce deep space
  travel times.
• Discover fundamentally new on-board energy
  production methods to power propulsion devices.

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Warp Speed
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Warp Speed

• To Infinity and Beyond

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Warp Drives

• Science Fiction has long talked of a warp
  speed, or faster than the speed of light
  transportation.
• 93 Mexican Physicist Miguel Alcubierre wrote
  paper on the physics behind a warp speed.
• First time scientist could talk about it in a
  scientific way.

• Chris Van Den Broeck followed up these ideas and
  wrote another influential paper.
• Van Den Broeck concludes "The first warp drive
  is still a long way off but maybe it has now
  become slightly less improbable."

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Warp Drive Theory

• Contracts Space-time in front of the ship, and
  expand it behind the ship, propelling the ship
  forward.
• Would require exotic material that Scientists are
  still debating about.

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Wormholes

• Can it be done?

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The Science Fiction Wormhole

• A hole in space time that links two places very
  far away from each other together
• Allows people to travel great distances in very
  short periods of time
• Better than traveling light speeds because light
  can take hundreds of thousands of years to travel
  the distances between galaxies

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History

• First discovered early in the 20th century, from
  Einsteins equations of general relativity
• Provide a connection between two regions of
  space-time, known as an Einstein-Rosen bridge

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Before the 1980s

• Wormholes were thought of as rotating black holes
• Two event horizons would emerge one as a result
  of gravity, the other the result of the black
  holes spin
• Gravity wants to pull the wormhole shut, but the
  force due to the black holes spin causes the
  wormhole to stay open
• Wormhole connects to many different places and
  many different times
• Time travel is also possible in this worm hole

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The Traversable Wormhole

• Carl Sagan was writing the novel Contact, and
  needed a way to travel great distances in space
  in a short period of time turned to his friend
  Kip Thorne at Caltech
• Thorne along with two graduate students
  discovered in 1985 nine golden rules for the
  traversable wormhole

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A wormhole that works???

• The wormhole must be static and spherical.
• The wormhole must obey Einsteins equations of
  general relativity.
• The wormhole must look like a flattened
  hourglass, with two basins connected by a
  narrow throat.
• There can be no event horizons.
• Gravitational tidal forces experienced by a
  traveler must be as small as possible.
• The trips duration according to the crew and to
  those left behind on earth must take less than
  one year.
• The matter and energy needed to form the wormhole
  must be physically reasonable.
• The wormhole must remain stable under the
  influence of the mass of the spaceship.
• It must be possible to complete the wormhole in a
  reasonable amount of time.

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But we cant use them

• A wormhole has a lot of mass to create the
  curvature of space time that is needed
• Therefore, requires exotic matter throughout
  the wormhole to prevent collapse due to
  gravitational forces
• Exotic matter is theoretically allowed through
  quantum mechanics- in empty space, matter and
  anti-matter (particles that have negative mass
  and negative energy) constantly appear out of
  nothing, come together and annihilate each other
• By placing a net near a black hole,
  theoretically, if the anti-matter particles get
  sucked into the black hole but are captured by
  the net, can obtain a supply of exotic matter
  to use on wormhole
• But that is far beyond our current technological
  capabilities

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This means

• Wormholes are theoretical possibilities, but no
  concrete evidence has ever been found to support
  their existence
• No technology available today to make use of
  them an advanced civilization might be able to
  use them, but for humans in the near future,
  travel through wormholes is impossible !

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Solar Sails
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What is a Solar Sail?

• Large, this, lightweight mirror
• Propelled by sunlight (9 N/km2 )

http//science.howstuffworks.com/solar-sail.htm/pr
intable
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What are Carbon Fibers?

• Micron thick carbon fibers woven together
• Stiff, withstands extreme heat of sun
• Density 1/10 oz/yard2

http//science.howstuffworks.com/solar-sail.htm/pr
intable
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Launching the Sails

• Launch sail via secondary vessel
• Can of gas
• NASA's Advanced Spin-Stabilized Sail
• Launch with microwave beams
• Laser beams to propel

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Considerations

• Stability
• Micrometeorites
• Return Voyage?

http//science.nasa.gov/headlines/y2000/ast28jun_1
m.htm
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Future

• 2005Demos
• 2010Interstellar Probe
• 2018Catch up with Voyager I
• Long distance exploration!

http//science.nasa.gov/headlines/y2000/ast28jun_1
m.htm
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Conclusion

• We are stuck! Space exploration is limited by
  our current technology in rocketry and space
  travel.
• Rocket propulsion is not the best way. We need
  alternatives.
• New ideas are based on both existing knowledge
  and imagination.
• Its possible! We can do it!