Using Earth's magnetic field for space propulsion

PJay_A · Oct 3, 2008

I've been thinking about this for quite awhile now. Somehow I think there is something to it, but I have not quite put my finger on it. The Earth's magnetic field is a limitless natural renewable energy source that no one has tapped into to take advantage of. I suspect that there must be a way to utilize this as a source for space propulsion.My initial thinking was that it could be used to change a satellite's orbit. This would be done be creating an electromagnetic wave polarized to push the satellite away for the Earth's magnetic field of opposite polarity and to pull it to the field's same polarity on the other side, pulsed and syncted so that its speed and direction are controllable. Later, I realized that the Earth's maganetic field feeds into the ground to space at the polar regions. Additionally, I realized that the fields capture plasma in space and stream it to the ground at the poles. Could that plasma and magnetism get captured somehow and drive a rocket engine off the ground and ito space? Or at least can it be harnessed and converted to electricity for the world's energy needs?

glutomoto · Oct 3, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>I've been thinking about this for quite awhile now. Somehow I think there is something to it, but I have not quite put my finger on it. The Earth's magnetic field is a limitless natural renewable energy source that no one has tapped into to take advantage of. I suspect that there must be a way to utilize this as a source for space propulsion.My initial thinking was that it could be used to change a satellite's orbit. This would be done be creating an electromagnetic wave polarized to push the satellite away for the Earth's magnetic field of opposite polarity and to pull it to the field's same polarity on the other side, pulsed and syncted so that its speed and direction are controllable. Later, I realized that the Earth's maganetic field feeds into the ground to space at the polar regions. Additionally, I realized that the fields capture plasma in space and stream it to the ground at the poles. Could that plasma and magnetism get captured somehow and drive a rocket engine off the ground and ito space? Or at least can it be harnessed and converted to electricity for the world's energy needs?  Posted by PJay_A</DIV> I don't know about from ground to orbit but some work has been done on Electrodynamic Tethers that could allow a spacecraft to generate electricity from the earth's magnetic field and use it for propulsion. http://www.tethers.com/EDTethers.htmlhttp://antwrp.gsfc.nasa.gov/apod/ap050328.html Even when not generating electricity the tether could be used to move a spacecrafthttp://www.tethers.com/MXTethers.html Is it time for more experiments like Tethered Satellite System 1 ?you bet it is.  <div class="Discussion_UserSignature"> </div>

crazyeddie · Oct 3, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>I've been thinking about this for quite awhile now. Somehow I think there is something to it, but I have not quite put my finger on it. The Earth's magnetic field is a limitless natural renewable energy source that no one has tapped into to take advantage of. I suspect that there must be a way to utilize this as a source for space propulsion.My initial thinking was that it could be used to change a satellite's orbit. This would be done be creating an electromagnetic wave polarized to push the satellite away for the Earth's magnetic field of opposite polarity and to pull it to the field's same polarity on the other side, pulsed and syncted so that its speed and direction are controllable. Later, I realized that the Earth's maganetic field feeds into the ground to space at the polar regions. Additionally, I realized that the fields capture plasma in space and stream it to the ground at the poles. Could that plasma and magnetism get captured somehow and drive a rocket engine off the ground and ito space? Or at least can it be harnessed and converted to electricity for the world's energy needs?  Posted by PJay_A</DIV>You're referring to a magsail, or magnetic sail, and it's a device the propulsion scientists have been considering for some time:A magnetic sail or magsail is a proposed method of spacecraft propulsion which would use a static magnetic field to deflect charged particles radiated by the Sun as a plasma wind, and thus impart momentum to accelerate the spacecraft [1] [2]. A magnetic sail could also thrust directly against planetary and solar magnetospheres.In typical magnetic sail designs, the magnetic field is generated by a hoop of superconducting wire. Because loops of current carrying conductor tend to be forced outwards towards a circular shape by their own magnetic field, the sail could be deployed simply by unspooling the conductor and applying a current through it. For a sail in the solar wind 1AU away from the sun, the field strength required to resist the dynamic pressure of the solar wind is 50nT. Zubrin's proposed magnetic sail design would create a bubble of space of 100km in diameter where solar wind ions are substantially deflected, using a hoop 50km in radius. The minimum weight of such a coil is constrained by material strength limitations at roughly 40 metric tonnes, and it would generate 70N of thrust[1], giving a mass/thrust ratio of 600kg/N. It is not clear how such a coil would be cooled.The operation of magnetic sails using plasma wind is analogous to the operation of solar sails using the radiation pressure of photons emitted by the Sun. Although solar wind particles have rest mass and photons do not, sunlight has thousands of times more momentum than the solar wind. Therefore, a magnetic sail must deflect a proportionally larger area of the solar wind than a comparable solar sail to generate the same amount of thrust. However it need not be as massive as a solar sail, because the solar wind is deflected by a magnetic field instead of a large physical sail. Conventional materials for solar sails weigh around 7 grams per square meter, giving a thrust of 1e-5 N/m2 at 1AU. This gives a mass/thrust ratio of at least 700kg/N, similar to a magnetic sail, neglecting other structural components.http://en.wikipedia.org/wiki/Magnetic_sail <div class="Discussion_UserSignature"> </div>

billslugg · Oct 4, 2008

There are some misconceptions in the first two posts in this thread.The Earth's magnetic field, nor any static magnetic field, is a source of energy. Yes, you can push and pull on it, but you have to supply the energy. With a tether, if a space craft extracts energy using the Earth's magnetic field, the space craft will slow down and drop down lower in orbit. If you use solar cells to run a current through the tether, then its interaction with the Earth's magneteic field can raise the satellite's orbit.But you cannot extract energy from the Earth's magnetic field with a tether and use that energy to raise your orbit.  <div class="Discussion_UserSignature"> </div>

PJay_A · Oct 4, 2008

Would it be possible to use this technology (when and if it is ever developed) to traverse from LEO to lunar orbit? If so, it could provide permanent access to the moon without having to launch the expensive Altair V each time!Now, think about that! Hmmmm

billslugg · Oct 4, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>Would it be possible to use this technology (when and if it is ever developed) to traverse from LEO to lunar orbit? If so, it could provide permanent access to the moon without having to launch the expensive Altair V each time!Now, think about that! Hmmmm  Posted by PJay_A</DIV>Sure. It just depends of how long a tether you have, how big a solar cell and how long you want to wait. Eventually you would attain an orbit so high that the Moon would would be close enough for insertion. (I believe that would require some additonal energy (not from a tether) though.) <div class="Discussion_UserSignature"> </div>

DrRocket · Oct 8, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>Sure. It just depends of how long a tether you have, how big a solar cell and how long you want to wait. Eventually you would attain an orbit so high that the Moon would would be close enough for insertion. (I believe that would require some additonal energy (not from a tether) though.) Posted by billslugg</DIV>As you correctly pointed out the energy to raise the orbit is coming from the solar cell.  Given a means of capturing energy from the sun (the solar cell) there are plenty of ways to use that energy to raise and orbit without making any use of the magnetic field of the Earth.  Some of those ways, say using the electrical energy generated to power an arc jet are pretty efficient, although the thrust itself is pretty low. <div class="Discussion_UserSignature"> </div>

exoscientist · Oct 9, 2008

Something like this has been speculated on:GEOMAGNETIC LEVITATION http://www.islandone.org/LEOBiblio/SPBI133.HTM This is a nice site by the way for some proposed near term solutions for cheap access to space:EARTH-TO-ORBIT TRANSPORTATION BIBLIOGRAPHY. http://www.islandone.org/LEOBiblio/   Bob Clark   <div class="Discussion_UserSignature"> </div>

Search

Using Earth's magnetic field for space propulsion

PJay_A

Guest

glutomoto

Guest

crazyeddie

Guest

billslugg

Guest

PJay_A

Guest

billslugg

Guest

DrRocket

Guest

exoscientist

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page