View Full Version : Propellant-free space propulsion

2002-Feb-07, 07:45 PM
Interaction between a tether and the ionosphere produces thrust (http://www.scienceagogo.com/news/20020106223110data_trunc_sys.shtml)

2002-Feb-07, 08:46 PM
On 2002-02-07 14:45, ToSeek wrote:
Interaction between a tether and the ionosphere produces thrust (http://www.scienceagogo.com/news/20020106223110data_trunc_sys.shtml)

Thanks for the very interesting article! Please excuse my ignorance in this matter, but the article did not say exactly how the propulsion itself works. The tether's contact with the ionosphere generates an electrical current, but what does the spacecraft do with that current to generate propulsion? Is it like that 1st grade experiment with the piece of soap sticking off the back of a matchbook in a sink full of clean water? Thanks!

2002-Feb-07, 08:53 PM
A bit more detail-


Very interesting stuff.

2002-Feb-07, 09:13 PM
Interesting. When I read the first article, I thought the were tapping into the solar wind. But upon reading the second, I realize I was way wrong. Using the Earth's own magnetic field, now that's clever.

<font size=-1>[ This Message was edited by: Wiley on 2002-02-07 16:18 ]</font>

John Kierein
2002-Feb-07, 09:25 PM
There are other ways to use tethers to help. You could tether a shuttle to the space station and as you reel it out the center of mass stays in orbit but the space station gets higher and the shuttle gets lower. Then you cut the tether and deorbit the shuttle. This raises the orbit of the space station without using propellant and lowers the orbit of the shuttle without using propellant.

2002-Feb-07, 09:26 PM
Basically, some of the electrons in the ionosphere flow through the cable, which then interacts with the Earth's magnetic field. This produces a force at right angles to both, the Lorentz Force.