Master templet

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Advanced Propulsion Concepts
ToNational Space SocietyHuntsville Alabama L5
Society John Cole November 12, 2004
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Contents

• The Goals and Objectives of the Presidents
  Vision
• The Horizons
• Avenues
• Chemical
• Electromagnetic
• Nuclear
• Concluding Remarks

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The Presidents Visionfor U.S. Space Exploration

• Goal and Objectives
• The fundamental goal of this vision is to advance
  U.S. scientific, security, and economic interests
  through a robust space exploration program.In
  support of this goal, the United States will
• Implement a sustained and affordable human and
  robotic program to explore the solar system and
  beyond.
• Extend human presence across the solar system,
  starting with a human return to the Moon by the
  year 2020, in preparation for human exploration
  of Mars and other destinations.
• Develop the innovative technologies, knowledge,
  and infrastructures both to explore and to
  support decisions about the destinations for
  human exploration.
• Promote international and commercial
  participation in exploration to further U.S.
  scientific, security, and economic interests.
• http//www.nasa.gov/missions/solarsystem/explore_
  main.html
• February 3, 2004

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The Horizons

• Human missions beyond Jupiter may require
• Velocity changes gt 200 km/s.
• Implies Initial Vehicle Specific Energy 14
  GJ/kg.
• For comparison a tank of H2 and O2 10 MJ/kg.
• Trip times of less than 23 years.
• Implies Initial Vehicle Specific power gt 310
  KW/kg.
• For comparison the Delta 4 provides 30 KW/kg.
• But Prometheus Jupiter Icy Moons Orbiter (JIMO)
  provides lt 20 Watts/kg.
• Payload mass similar to ISS plus an equal
  propellant mass.
• Extraterrestrial assembly, possibly lunar
  manufacturing.
• Many orbit transfer missions.
• Many launches from Earth.
• Propulsion technologies in the pipe-line can get
  us started (Atlas V, Delta IV, JIMO).
• Clearly, advanced propulsion technologies are
  needed.
• Very little is completely new, relook at
  overlooked ideas.
• Many Avenues Exist Some May Lead To Solutions.
• February 3, 2004

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Earth Escape

• Earth escape durations
• Of a few days will requiregt 100 W/kg, total
  vehicle.
• Of a few months will requirelt 10 W/kg.
• 100 MT to escape implies power levels of 110 MW.
• New solar array technologies ofgt 300 W/kg (just
  arrays) should enable vehicles withPsp 20 W/kg
  andfuel fractions lt 0.1.
• Prometheus nuclear electric propulsion (NEP) type
  technology will provide avehicle Psp gt 20 W/kg.

Assumes constant acceleration perpendicular to
the gravity.
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Round-trip Planetary Missions
Propellant Fraction 0.632

• Round trips of 2 to 3 years to points beyond Mars
  imply a large initial Vehicle Specific Power of
  3 to 10 KW/kg.
• This is well beyond the current capabilities of
  solid or liquid core reactor concepts.

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Potential Research

• Advanced chemical propellants
• Focus on high energy density materials (HEDM).
• Energy density of chemical propulsion is
  fundamentally limited but significant potential
  performance gains do exist.

High energy, environmentally benign
monopropellants.
Metallic Hydrogen Synthesis
Solid molecular hydrogen particles (H2 matrix)
formed on liquid helium surface (circled area)
EnergeticHydrocarbon Fuels
Ionic Liquid Monopropellant
Recombination Energy Fuels
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High-energy Density Monopropellants
The Air Force has formulated several
monopropellants that substantially outperform
hydrazine and even surpass bipropellants for some
applications.

NH3OH NO3-
Novel energetic salts have higher energy
densities and reduced vapor toxicities compared
with hydrazine.
Enabling new missionssmaller vehicles, more
payload, higher ?V, longer useful vehicle
lifetime. Cutting costsmonopropellant-based
propulsion systems are simpler, smaller, and less
costly than bipropellant systems.
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Metallic Hydrogen

• What is metallic hydrogen? Under intense pressure
  the hydrogen atoms become so close together that
  the electrons easily move from atom to atom.
• Most solid state theories predict metastable
  state, will remain in the metallic form when the
  pressure is released up to an unknown critical
  temperature
• Benefits
• The estimated specific impulse of metallic
  hydrogen is 1,700 second. Specific energy 140
  MJ/kg.
• The density will be much higher than liquid
  hydrogen.
• The performance improvement may reduce costs.
• Research Objectives
• To find whether metallic hydrogen can be
  produced.
• Then determine if metastable and critical
  temperature
• Can metallic hydrogen be affordably produced,
  handled, and used?
• Metallic Hydrogen enables single-stage-to-Lunar
  or Mars landing and return!

Diamond anvil cell, Silvera
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Energetic Combustion Devices

• Powdered Metal Combustion Technology
• Endoatmospheric Mars propulsion.
• Metals/CO2 combustion utilizes in-situ resources.
• Ascent stage for Mars sample return mission.
• Thermal driver for pulse power MHD generator.
• Nonequilibrium Plasma Generator (NPG) concept.
• High-power airborne auxiliary power unit (APU).
• Adapt existing experimental device to investigate
  fundamental combustion processes.
• Pressurized rig with optical access.
• Positive displacement fluidized bed feed system.
• Demonstrate prototypical rocket mode operation.

Powdered Metals Research Combustor
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Potential Research

• Electromagnetics and Plasma-based Propulsion
• Focus on MW-Class electric thrusters.
• Plasma production, control, and containment.
• Electromagnetic launch assist.
• Components (flightweight and high-power).
• Includes beamed energy propulsion.

Electric Microthrusters
Magnetohydrodynamic Augmented PropulsionExperimen
t (MAPX)
MHD-augmented Thrusters
Flightweight Magnets
Electromagnetic Launch Assist
MW-class Electric ThrustersEnabling for
High-power NSI
Beamed Energy Propulsion
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Horizontal Launch Assist

• Weight Savings
• Some fuel reduction from initial velocity
• For a Horizontal Take-Off, Horizontal Landing
  (HTHL) vehicle the thrust and engine weight is
  60 that for VTHL.
• Launch assist can reduce take-off and landing
  gear to that needed for landing.
• 200 m/s launch assist can reduce wing size to
  that needed for landing empty.
• Electromagnetic launch assist has now been
  developed by the Navy.
• Flywheel energy storage technology is mature and
  improving.
• This technology is ready forreconsideration.

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Gallium Electromagnetic Thruster

• Gallium Electromagnetic Thruster (GEM)
• Two-stage pulsed plasma thruster that avoids gas
  valves and high-current switches and mitigates
  electrode erosion.
• Performance characteristics
• 50500 kW power level.
• 5,000100,00 sec Isp, variable.
• gt50 efficiency.

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Plasmoid Thruster

• Plasmoid ThrusterAn inductive pulsed plasma
  thruster that repetitively forms and accelerates
  a compact toroidal (magnetized) plasmoid.
• Performance characteristics
• 100 kW1 MW power level.
• 5,00010,000 sec specific impulse.
• gt 50 efficiency.

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Variable Specific Impulse Magnetoplasma Rocket
(VASIMR)

• Helicon plasma is heated using ion cyclotron
  resonance heating (ICRH), ejected through
  magnetic nozzle.
• No electrodes or other materials in direct
  contact with the plasma.
• Therefore, potential for very high power density,
  high reliability, long life.
• Multiple propellants hydrogen, deuterium,
  helium, nitrogen, argon, xenon, and others.
• Scalable beyond 10s of megawatts.
• The biggest challenge is energy efficiency at low
  specific impulse.

NASA Johnson Space Center Advanced Space
Propulsion Laboratory
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Helicon-Electron-Cyclotron-Resonance Acceleration
Thruster (HEAT)

• Uses antenna and plasma waves instead of
  electrodes.
• Radio waves heat plasma.
• Magnetic field accelerates hot plasma.
• No electrodes
• Increases operating life.
• Allows in situ propellant use in space.

Small (10 cm long, 2 cm diameter) helicon source
in operation.
Glenn Research Center
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Jupiter Icy Moons Orbiter
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Advanced Nuclear Propulsion

• Advanced Nuclear Propulsion
• Focus on high specific energy/power concepts.
• Highly enabling for human/robotic exploration.
• 106 improvement in specific energy over chemical.
• Potential for system specific power gt 1 kW/kg.

(U,Zr,Nb)C Sample
High-temperature Fission Fuels
Nuclear Isomers (nonfissioning)
Aerojet Corp Test Rig LANTR hot fire test (251
area ratio)
Antimatter
Advanced Fission Systems
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Simulated ReactorSystem Demonstrations

• SAFE-100a Simulation
• Prototypical reactor power level.
• Vacuum environment.
• Insulated core, HX, HP condensers.
• Checkout testing ongoing.
• Goal is to demonstrate operation of integrated
  system.

SAFE-100a (uninsulated)
Automated Test Facility Operations
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Pulsed Gas Core ReactorNon-nuclear Test

• This schematic of the conceptual design for the
  PMI-FPS represents the most fully formed concept
  to date, incorporating all three prior aspects
  of
• Shockwave generation, shock collision and fission
  energy release, and magnetic flux compression
  power generation.
• In addition to a new fourth component, a radial
  compaction of plasma by theta-pinch.

INSPPI, Univ. Fla.
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Fusion Propulsion
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Human Outer Planet Exploration
Revolutionary Aerospace Systems Concepts
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Antimatter

• Annihilation with matter yields187 MJ/microgram.
• Compare with combustion, H2/O2at 10 MJ/kilogram.
• Penning traps can store gt 1014 antiprotons.
• Propulsion concepts use antimatter to trigger
  microfission or fusion.
• Example concept is an antimatter sail.

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Other Concepts
Solar Thermionic
http//www.inspacepropulsion.com/tech/aerocapture.
htmlAerocapture
Myrabo, RPI Microwave Beamed Energy Propulsion
http//www.grc.nasa.gov/WWW/bpp/ Emerging Physics
www.inspacepropulsion.com/tech/tethers.html MXER
Tether
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Concluding Comments

• Human missions beyond Mars will require
  propulsion technologies beyond those currently
  being developed.
• ChemicalSpecific Energy gt 10 MJ/kg.
• NuclearSpecific Power gt 10 KW/kg.
• Many old concepts that were immature may now be
  ready for another look.
• Research is slow business, but not expensive.
• Avenues exist.

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Back-up Charts
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Reusable Single Stage to Orbit

• NOT YET!
• SSTO is currently not quite achievable, limited
  by
• Fuel specific energy.
• Mass of wheels, wings, tanks, and engines.
• Reusable vehicles are not cost-effective until
  flight ratesgt 25 flights/year.
• What We Like to Have
• Ultimately, frequent flights of an SSTO vehicle
  are desired.
• Reduced fuel fraction enables
• More payload.
• Added safety features.
• Added operability features.
• What is needed
• High specific energy fuels (gt10 MJ/kg).
• Off-board energy, launch assist.
• Stages.

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Mag-Beam Concept
John Carscadden, University of Washington.

• A space-based station generates a stream of
  magnetized ions.
• The ions interact with a magnetic sail on a
  spacecraft to provide propulsion.
• NASA Institute for Advanced Concepts Phase I
  75,000 contract for a six-month study to
  validate the concept and identify challenges.

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