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by stcredzero
3979 days ago
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There's been some nifty work done on the practicality of electrodynamic tethers and using them to turn a starship against the galactic magnetic field. You won't get sci-fi ship maneuverability out of this, but it's useful for course corrections without having to carry or expend reaction mass. As far as onboard power sources go, fission seems perfectly cromulent. You just have to protect those radiators. |
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> Since the tether current is 1,333 amps, ne = 3 X 10‘‘ m-3 and the ship’s velocity is 900 km/sec, the effective electron-collector radius is approximately 3 13 km.
This appears to have a toroidal-field ramscoop as a prerequisite.
For thrustless turning, a 0.06 degree turn requires a tether 10^3 km long:
> To obtain a six-degree trajectory modification during a 1,400-year journey with the tether current assumed, the tether length must be increased by a factor of lOOX to equal l0^5 km. This would increase tether mass to 2.7 X lo5 kg.
And this is using a reference ship many scientists are skeptical about:
> ...it is assumed here that the primary propulsion for these ships is the ultra-thin, space manufactured solar sail unfurled as close to the Sun as possible at the perihelion of a parabolic or hyperbolic solar orbit. After acceleration to interstellar cruise velocity, it is also assumed that sail and cables are wound around the habitat section to provide extra cosmic ray shielding. The sail is unfurled again for deceleration at the destination star.... since the baseline sailcraft for this analysis is somewhat faster, either more advanced sail/cable materials are required or the pre-perihelion orbit is hyperbolic.
I'd definitely categorize that under "experimental power sources and unproven physics." Perhaps you are thinking of a different article?