Course Summary Session:Course Summary Session:

Trajectories, Chemical Rockets, Trajectories, Chemical Rockets,

Plasma Propulsion, Fusion PropulsionPlasma Propulsion, Fusion Propulsion

John F SantariusJohn F Santarius

Lecture 43Lecture 43

Resources from SpaceResources from Space

NEEP 533/ Geology 533 / Astronomy 533 / EMA 601NEEP 533/ Geology 533 / Astronomy 533 / EMA 601

University of WisconsinUniversity of Wisconsin

Efficient Solar-System Travel RequiresEfficient Solar-System Travel RequiresHigh-Exhaust-Velocity, Low-Thrust PropulsionHigh-Exhaust-Velocity, Low-Thrust Propulsion

• Electric power can be used to drive high-exhaust-velocity Electric power can be used to drive high-exhaust-velocity plasma or ion thrusters, or fusion plasmas can be directly plasma or ion thrusters, or fusion plasmas can be directly exhausted.exhausted.

– Allows fast trip Allows fast trip times or large times or large payload fractions payload fractions for long-range for long-range missions.missions.

• Uses relatively small Uses relatively small amounts of propellant, amounts of propellant, reducing total mass.reducing total mass.

Fusion rocketFusion rocket(( specific powerspecific power))

2JFS 1999 University of Wisconsin

3JFS 1999 University of Wisconsin

Plasma Thrusters Give High Exhaust VelocityPlasma Thrusters Give High Exhaust Velocity

Electrostatic thrusterElectrostatic thruster Electrodynamic thrusterElectrodynamic thruster

From University of Stuttgart’s web page:From University of Stuttgart’s web page:

www.irs.uni-stuttgart.de/RESEARCH/www.irs.uni-stuttgart.de/RESEARCH/

EL_PROP/e_el_prop.htmlEL_PROP/e_el_prop.html

Electrothermal thrusterElectrothermal thruster

From Robert Jahn,From Robert Jahn,Physics of Electric Propulsion (1968)Physics of Electric Propulsion (1968)

D-D-33He Fusion Would OutperformHe Fusion Would Outperform D-T Fusion for Space Applications D-T Fusion for Space Applications

• High charged-particle fraction allows efficient High charged-particle fraction allows efficient direct conversion to thrust or electricity.direct conversion to thrust or electricity.

–Increases useful power.Increases useful power.

–Reduces heat-rejection (radiator) mass.Reduces heat-rejection (radiator) mass.

–Allows flexible thrust and specific-impulse Allows flexible thrust and specific-impulse tailoring.tailoring.

• Low neutron fraction reduces radiation shielding.Low neutron fraction reduces radiation shielding.

• D-3He eliminates need for a tritium-breeding D-3He eliminates need for a tritium-breeding blanket.blanket.

4JFS 1999 University of Wisconsin

Field-Reversed Configurations Appear Field-Reversed Configurations Appear Attractive for Fusion Space PropulsionAttractive for Fusion Space Propulsion

From Univ. of Washington web page for the Star Thrust Experiment (STX):From Univ. of Washington web page for the Star Thrust Experiment (STX):www.aa.washington.edu/AERP/RPPL/STX.htmlwww.aa.washington.edu/AERP/RPPL/STX.html

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