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- From: hollis@titan.ksc.nasa.gov
- Newsgroups: sci.space.shuttle
- Subject: Electric propulsion
- Message-ID: <1992Aug18.122536.3200@titan.ksc.nasa.gov>
- Date: 18 Aug 92 17:25:36 GMT
- Organization: NASA, Kennedy Space Center
- Lines: 36
-
- Greetings and Salutations:
-
- >From: Nir.Oren@f54.n7101.z5.fidonet.org (Nir Oren)
- >How would one create thrust in space using an electric motor
- >(without firing electrons backwards etc...) ?
-
- A good book for good discussion of rockets is "ROCKET PROPULSION ELEMENTS : An
- introduction to the engineering of rockets" Sixth edition, George P. Sutton.
- Be sure to pick up the sixth edition (1992) because he put different types of
- oddball propulsion back in that he took out in the fifth edition.
-
- To produce thrust, you have to fire something backwards (exhaust), or use the
- forward momentum of SOMETHING to move (solar sail, etc.). TANSTAAFL - There
- Ain't No Such Thing As A Free Lunch.
-
- There are three fundamental types of electric propulsion.
-
- Electrothermal - Propellant is heated electrically and is thermodynamically
- expanded and the heated gas is accelerated to supersonic speeds through the
- nozzle as in a chemical rocket. Typical propellants H2, Ns, N2H4.
-
- Electrostatic - Acceleration is achieved by the interaction of electrostatic
- fields on charged propellant particles, such as ions and charged colloids.
- Typical propellants are Xenon, cesium or mercury.
-
- Electromagnetic - Acceleration is achieved by the interaction of electric and
- magnetic fields on highly ionized plasma. A plasma is a high temperature
- electrically neutral gas containing electrons, ions and neutral species.
- Propellant is not really applicable because of temperatures of 5600 K or 10,000
- R allow anything to be used, however Teflon was used as the solid propellant
- ablated off in the LES-6 pulsed plasma thruster.
-
- --
- -----------------------------------------------
- Ken Hollis INTERNET: HOLLIS@TITAN.KSC.NASA.GOV
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