| Hmm, there's a throwback. I first encountered space tethers in 1980 reading an Introduction to Engineering text where the example was given of unrolling a flat spool of thin metal through shaping rollers to extrude a very long boom with a spring on the end to stabilise the orientation of a satellite. That was one of the first times I noodled about with the dynamics of a pendulum in a potential field. These days, of course, there's a few more tricks that can be done with a dangling lasso, including interacting with the magnetic field via a looped current. That aside, I was curious about traditional magnetorquers and their variations actively providing force in the magnetosphere. The Earths magnetic field has a lot of diurnal pulsing .. the gravitational field is lumpy but stable. There's a control challenge in getting a smooth desired response from a choppy field. Cheer's for the lookout though, it hadn't occurred to me that some would be talking about magnetic force against the field using "space tether" as the base description - my background was more about the field equations than the physical implementation. ( Magnetorquers are also used in the US Navy for twisting controls inside a fully sealed container. ) |