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'Acceleration without fuel:' Revolutionary superconducting thruster harnesses Earth's magnetic field in 1st orbital test (www.space.com)
submitted 3 months ago by to c/space@mander.xyz
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..."Once you have super-conducting technology available in space, you can then create very strong magnetic fields and you can use them for various use cases," he said. "You can accelerate things in space very fast or change the trajectory of a satellite completely without fuel."...

"When we go to space, we get hurt by radiation, and these superconducting magnets can create umbrellas of magnetic fields around the spacecraft to protect the interior," said Arshavsky. "So we can shield people in space from that radiation."...

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[–] 14 points 3 months ago (10 children)

Except right now, superconductors only work at very low temperatures, and keeping things at low temps in space requires energy.

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  • [–] 21 points 3 months ago (2 children)

    Energy is easy enough to get in space with some solar panels and a battery, while fuel has to be sent with the payload. Even if it's not good enough for constant function, being able to spin them up long enough for a course correction is a pretty big deal.

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  • [–] 0 points 3 months ago (1 child)

    Right, but then it's not really "without fuel." It's hopefully less fuel, and if you can run it on solar panels, it would be without resupply, but nuclear power could also provide long-term functionality. As always, the most fuel is spent getting things into orbit.

    For me, the exciting bit is the magnetic radiation shielding. If we're going to leave earth behind, radiation shielding is currently a significant missing piece of the puzzle.

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  • [–] 3 points 3 months ago

    They're not claiming the launch won't use fuel, just manoeuvring in space, which still solves the problem of getting fuel for manoeuvring while in space. Fuelless launches are a separate issue that other people are working on.

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  • [–] 7 points 3 months ago

    Technically, it needs insulation and a way to radiate heat. I read a while back that the superconductors used in space are often wrapped in several concentric shells to avoid being exposed directly to the sun and other onboard heat sources.

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  • [+] -10 points 3 months ago* (last edited 3 months ago) (5 children)

    No, keeping parts of things cold in space is easy. As long as something isn't being hit by direct solar radiation then the default temperature is negative several hundred degrees

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  • [–] 20 points 3 months ago (4 children)

    Technically yes, due to the extreme distances between particles in space we'd average a volume and say "negative temperature!".

    However.

    Those individual particles are shooting at extreme speed and momentum, so they're individually very hot.

    And due to the lack of particles bouncing around in a given volume of space, you can't use conduction/convection (aka, here fellow particles, take some of my energy). Instead you can only use radiative cooling, which is crazy inefficient. For example, the ISS has 75KW of cooling across 1000 square meters.

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  • [–] -4 points 3 months ago (3 children)

    But once it's cool it stays cool. Anything behind a radiation shield will stay cool forever

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  • [–] 17 points 3 months ago (1 child)

    Until it turns on. Then boom, waste heat.

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  • [–] 3 points 3 months ago*

    Though in all fairness that isn't much of a problem for a superconductor - no resistance, no waste heat when power runs through it.

    The main problem would be the waste heat from the rest of the system rather than the superconductor itself, so maintaining a superconductor cool is more a thermal insulation problem and the near vacuum of space actually helps in doing it because it removes the heat transmission from the hotter parts of the system to the superconductor via the environment (though, of course, it still happens via the solid parts in contact with it, so the thermal insulation is needed there)

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