Ion Propulsion

Improved designs in ion engines may be the ticket for making trips to the outer solar system quicker and more feasible both for unmanned probes and (I hope) manned spacecraft. I haven’t been keeping up with space exploration as much as I used to, so I am glad to find this article in Gizmag which explains a little about ion engines and how scientists have been making them better.

The phrase “engage the ion drive” still has the ring of a line from Star Wars, but these engines have been used in space missions for more than four decades and remain the subject of ongoing research. Ion engines have incredible fuel efficiency, but their low thrust requires very long operating times … and therein lies the rub. To date, erosion within such an engine seriously limits its operational lifetime. Now a group of researchers at NASA’s Jet Propulsion Laboratory (JPL) has developed a new design that largely eliminates this erosion, opening the gates for higher thrust and more efficient drives for manned and unmanned missions to the reaches of the Solar System.

There are many varieties and more proposals (the VASMIR engine comes to mind), but the operating principle is quite simple. There are two basic styles of ion engines, electrostatic and electromagnetic.

An electrostatic ion engine works by ionizing a fuel (often xenon or argon gas) by knocking off an electron to make a positive ion. The positive ions then diffuse into a region between two charged grids that contain an electrostatic field. This accelerates the positive ions out of the engine and away from the spacecraft, thereby generating thrust. Finally, an neutralizer sprays electrons into the exhaust plume at a rate that keeps the spacecraft electrically neutral.

An electromagnetic ion engine also works by ionizing a fuel. In this case a plasma is created that carries current between the ionizing anode and a cathode. The current in turn generates a magnetic field at right angles to the electric field, and thereby accelerates the positive ions out of the engine via the Lorentz force – basically the same effect on which railguns are based. Again a neutralizer keeps the spacecraft electrically neutral.

There are many varieties and more proposals (the VASMIR engine comes to mind), but the operating principle is quite simple. There are two basic styles of ion engines, electrostatic and electromagnetic.

 

There is a lot more in the article.

Even Scotty would be impressed by this.

Though, what we really need is warp drive. Anyone doing research on that?

 

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2 Responses to “Ion Propulsion”

  1. Kevin Edwards Says:

    The quote includes a duplicated portion.

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