Non-Keplerian Orbits Using Low Thrust, High ISP Propulsion Systems
Non-chemical Propulsion
Transcript of Non-chemical Propulsion
NON-CHEMICAL PROPULSIONPresented by:Mashooq O
CONTENTS Introduction Types of Non-chemical propulsion systems Description Advantages
WHAT IS PROPULSION? Means of creating force leading to movement Source of mechanical power used to
generate force
INTRODUCTION Chemical Propulsion involves the chemical
reaction of propellants to move or control a spacecraft
Primary propulsion, reaction control, station keeping, precision pointing, and orbital manoeuvring
Non-chemical Propulsion eliminates the use of chemical reactants
TYPES OF NON-CHEMICAL PROPULSIONElectric Propulsion Electro Thermal Resistojets
ArcjetsElectrostatic Ion Thrusters
Hall ThrustersElectromagnetic Pulsed Inductive
Magnetoplasmadynamic
Thermal Propulsion
Solar Thermal
Nuclear Thermal
Solar Sail Propulsion Solar Sails
ELECTRIC PROPULSION Uses electrical energy to change the velocity
of a spacecraft Work by electrically expelling propellant at
high speed
ELECTROTHERMAL Propulsion of spacecraft by using an electric
arc or other electric heater Bring propellant to high temperature
RESISTOJETS Use an electrically heated element in contact
with the propellant Increase the enthalpy prior to expansion
through a nozzle Commercial communications satellites for
station keeping, orbit insertion, attitude control, and de-orbiting
Power level ranging from 467-885W Low power (80%) and very high specific
impulse (2000 to over 10,000 seconds)
ARCJETS Uses electric arc to heat the propellant prior
to expansion through a nozzle Primarily used in commercial
communications satellites for station keeping Power level ranges from 1670 to 2000W
ELECTROSTATIC PROPULSION Rely upon electric fields for accelerating and
expelling ions to produce thrust and propel the space craft
Electrically charges atoms from an on-board fuel supply
Inert gas is injected into the ionisation chamber then expelled for propulsion
ION THRUSTERS Employ a variety of plasma generation
techniques to ionize a large fraction of the propellant
High voltage grids extract the ions from the plasma
Electrostatically accelerate them to high velocity
HALL THRUSTERS Utilize both electric and magnetic field to
generate the plasma Perpendicular electric field accelerates ions
to high exhaust velocities Transverse field inhibits electron motion that
would tend to short out the electric field Produces Isp 1200-2000 seconds and
efficiency of 50-70%
ELECTROMAGNETIC PROPULSION Accelerating an object by the utilization of a
flowing electrical current and magnetic fields Either create an opposing magnetic field, or
to charge a fluid, which can then be repelled
PULSED INDUCTIVE THRUSTER Creates plasma by inductive breakdown of
gaseous propellant transiently puffed onto the surface of an induction coil
Energy stored in a bank of capacitors Generates a flat ring of current Efficiency of greater than 50%, and an Isp of
2000-9000 seconds in a single pulse
MAGNETOPLASMADYNAMIC THRUSTER Employ the interaction of high currents with
magnetic fields to accelerate ionized propellant
Offer high efficiency and very high power processing capability in a small volume
Variants on the MPD thruster: steady state self-field engines, steady state applied-field engines and quasi-steady thrusters
Efficiencies of over 50% at Isp greater than 10,000 seconds
THERMAL PROPULSION Propellant is heated Heated propellant would be fed through a
conventional rocket nozzle to produce thrust
SOLAR THERMAL PROPULSION Heats the propellant with concentrated
sunlight inside an absorber cavity Solar energy is focused inside either a direct
gain or thermal storage type engine configuration
Engine operated as a heat exchanger with the propellant
Provides a very high specific impulse (~500–1200 seconds)
Solar concentrator may be rigid, segmented or inflatable
NUCLEAR THERMAL PROPULSION High thrust, high Isp propulsion technology Demonstrated thrusts double that compared
to chemical propulsion Comprises of two: Fusion and Fission
propulsion High Isp allows reductions of the initial mass
in low earth orbit 7,500 to 250,000 lbs of thrust with specific
impulses of 800 to 900 seconds
SOLAR SAIL PROPULSION Uses sunlight to propel vehicles through
space Technology uses solar photons which are
reflected off sails made of lightweight, reflective material
Continuous photonic pressure provides enough thrust to perform manoeuvres
SOLAR SAILS Require no on-board propellant, thus
reducing payload mass Produce thrust by reflecting solar photons
and thus transferring much of their momentum to the sail
Demonstrated both photon acceleration and attitude control
Due to the constraints of gravity, solar sail propulsion performance is limited
ADVANTAGES OF NCP SYSTEMS Non-chemical propulsion require much less
propellant to produce the same overall effect Produced force can be applied continuously
for very long periods Electric thrusters possess the ability to
regulate the force applied to the spacecraft very accurately
Solar thermal systems have longer-life, lower-cost, more-flexible cryogenic upper stage and reusable inter-orbital tugs
Nuclear rockets are more fuel efficient and much lighter than chemical rockets
Condensed trip times would help reduce astronaut and instrument exposure to harmful radiation
The major advantage of a solar-sail spacecraft is its ability to travel between the planets and to the stars without carrying fuel.
Solar-sail spacecraft, which have gradual but constant acceleration, can achieve greater velocities than conventional chemical rockets
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