A seminar report on Electric Propulsion

A SEMINAR REPORT ON

ELECTRIC PROPULSION

BY

SAKTI PRASAD MISHRA

M.Sc. Applied Physics and Ballistics

PLANE OF TALK• What is propulsion

• About Electric Propulsion

• History of Electric propulsion

• Difference between Chemical & Electric propulsion

• Types of Electric propulsion

• Advantages

• Application

• Conclusion

• References

PROPULSION

• Propulsion in a broad sense is the act ofchanging the motion of a body.

• Propulsion mechanisms provide a force thatmoves bodies that are initially at rest, changesa velocity, or overcomes retarding forces whena body is propelled through a medium.

ELCTRIC PROPULSION• Propellant is heated electrically.

• The hot gas is then thermodynamically expandedand accelerated to supersonic velocity through anexhaust nozzle.

• Thrust ranges of 0.01 to 0.5 N, with exhaustvelocities of 1000 to 5000 m/sec.

• Ammonium, hydrogen, nitrogen, or hydrazinedecomposition product gases have been used aspropellants.

• Electric power can come from a battery, solarpanels or an onboard nuclear or solar generator.

HISTORY

1903 -- K. E. Tsiolkovsky derived the “Tsiolkovsky”or “Rocket” Equation commonly used to show thebenefits of electric propulsion

1906 -- R. Goddard wrote about the possibility ofelectric rockets

1911 -- K. E. Tsiolkovsky independently wrote aboutelectric rockets

1929 -- World’s first electric thruster demonstratedby V. P. Glushko at the Gas Dynamics Laboratory inLenningrad

1960 -- First “broad-beam” ion thruster operated inthe U.S. at the NASA Lewis (now Glenn) ResearchCenter

1964 -- First successful sub-orbital demonstration ofan ion engine (SERT I) by the U.S.

1964 -- First use of an electric thruster on aninterplanetary probe (Zond 2) by the USSR

1970 -- Long duration test of mercury ion thrusters inspace (SERT II) by the U.S.

1972 -- First operation of a xenon stationary plasmathruster (SPT-50) in space (Meteor) by the USSR

1993 -- First use of hydrazine arcjets on acommercial communications satellite (Telstar 401)by the U.S.

Difference between Chemical & Electric propulsion

Limitations of Chemical Rockets

• Chemical rocket: exhaust ejection velocity intrinsically limited

by the propellant-oxidizer reaction

• Larger velocity increment of the spacecraft could be obtained

only with a larger ejected mass flow.

• Mission practical limitation: exceedingly large amount of

propellant that needs to be stored aboard

Types of Electric propulsion

• Electrothermal

• Propellant is heated electrically and expandedthermodynamically; i.e., the gas is accelerated to supersonicspeeds through a nozzle, as in the chemical rocket.

• Electrostatic

• Acceleration is achieved by the interaction of electrostaticfields on non-neutral or charged propellant particles such asatomic ions, droplets, or colloids.

• Electromagnetic

• Acceleration is achieved by the interaction of electric andmagnetic fields within a plasma. Moderately dense plasmasare high temperature or non equilibrium gases, electricallyneutral and reasonably good conductors of electricity.

Electrothermal • RESITOJET

• Resistojets operate by direct heating of the propellant.

• In a typical resistojet, the propellant is heated in passingover a tungsten heating element within a heat exchangechamber before being exhausted, wherein heat istransferred to the propellant from some solid surface, suchas the chamber wall or a heater coil.

• Resistojets have been proposed for manned long-durationdeep space missions, where the spacecraft's waste products(e.g., H20 or CO2) could then be used as propellants.

Arcjets• The arcjet overcomes the gas temperature limitations of the

resistojet by the use of an electric arc for direct heating of thepropellant stream to temperatures much higher than the wall

temperatures.• The arc stretches between the tip of a central cathode and an

anode, which is part of the coaxial nozzle that accelerates theheated propellant.

Advantages• High exhaust speed (i.e. high specific impulse),

much greater than in conventional (chemical) rockets

• Much less propellant consumption (much higher efficiency in the fuel utilization)

• More energy available, less propellant, less mass required

• Continuous propulsion: apply a smaller thrust for a longer time

Application• For very precise low-thrust station-keeping and attitude

control applications, pulsed thrusters are generally bestsuited.

• Interplanetary Missions

• International space station(ISS)

• Commercial

• Defence

Conclusion

• If a system requires a propulsion system that is at the low endof the chemical thrust regime, then electric propulsion maybe a way to save spacecraft mass and/or increase the payloaddeliverable.

• For mostly political reasons, plans for deployment of nuclear high-powersources in space have so far failed to materialize, and consequently theuse of electric thrusters for primary propulsion in energetic missions hashad a cyclical history of false starts and disappointments.

• Now that many EP systems have entered the mainstream ofastronautic technology, their role in helping to expand humanambition beyond the inner part of the solar system, although stilldependent on the hitherto unrealized development of high-powersources, is perhaps on more credible ground.

References

• 1. Rocket and space craft propulsion book by Martin J.L.Turner Third Edition.• 2. Rocket propulsion element by George p. Sutton Seventh Edition.• 3. Electric Propulsion: Which One For My Spacecraft? Ian J. E. Jordan JHU, Whiting School of Engineering.• 4. A Critical History of Electric Propulsion: The First Fifty Years (1906-1956) Edgar Y. Choueiri∗ Princeton

University Princeton, New Jersey 08544• 5. Fundamentals of Electric Propulsion: Ion and Hall Thrusters Dan M. Goebel and Ira Katz• 6. M.S. El-Genk. Energy conversion options for advanced radioisotope power systems. In Space Technology

and Applications International Forum (STAIF 2003), volume 654(1), pages 368–375. American Institute of Physics, New York, 2003.

• 7. S. Oleson and I. Katz. Electric propulsion for Project Prometheus. In 39th Joint Propulsion Conference, Huntsville, AL, 2003. AIAA-2003- 5279

• 8. N.A. Rynin. Tsiolkovsky: His Life, Writings and Rockets. Academy of Sciences of the USSR, Leningrad, 1931.• 9. R. G. Jahn. Physics of Electric Propulsion. McGraw-Hill, New York, 1968.• 10. R.H. Goddard. The green notebooks, vol. # 1. The Dr. Robert H. Goddard Collection at Clark University

Archives, Clark University, Worceseter, MA 01610.• 11. Stuhlinger, E., Electric Propulsion Development, Progress in Astronautics and Aeronautics, v. 9, AIAA,

Academic Press, 1963.• Electric Propulsion Websites:• 1.Frisbee, R. http://sec353.jpl.nasa.gov/apc/index.html .• 2.Advanced Space Propulsion Research Workshop May 31 / June 2, 2000 - JPL. Proceedings papers• may be found at http://apc2000.jpl.nasa.gov/ .

3.A somewhat out of date compilation of electric propulsion sites may be found at http://www.irs.unistuttgart.de/SURF/ep_sites.html .