7 ms·

Hmm, could we use interactions with the Earth's magnetic field for thrust when in LEO? With the Sun's magnetic field? It would be slow going.

• hooo 8y ago
  Yes, I remember reading about people using this to deorbit satellites... though I can't find the link right now.
• db48x 8y ago
  Yes, satellites already do this.
• cheesepizza1077 8y ago
  Yes there are various forms of electromagnetic drives that use the earths magnetic field for small tasks like rotation and (maybe) station keeping. There are a few types, some which use propellant, and some that do not. More info here: https://en.m.wikipedia.org/wiki/Electrically_powered_spacecraft_propulsion https://en.m.wikipedia.org/wiki/Electrically_powered_spacecr...
• sigstoat 8y ago
  this is suggested frequently in these threads. it is already used in the very limited application where it is useful. https://en.wikipedia.org/wiki/Magnetorquer https://en.wikipedia.org/wiki/Magnetorquer "It is also impossible to control attitude in all three axes even if the full three coils are used, because the torque can be generated only perpendicular to the Earth's magnetic field vector." the non-earth orbiting mission i worked on didn't have any; it used little thrusters to desaturate its reaction wheels.
• ben_w 8y ago
  Yes, sort of, but that’s mainly useful for torque rather than thrust as thrust relies on (if I’m getting this right) field gradients rather than absolute field strength. It’s not nothing, but it might as well be. I back-of-enveloped a launch system with a very big magnet on the ground, supplying a much steeper gradient to push against, and it was still crazy expensive. (I wonder if it would be useful for skyhooks?)